1. A Successful Second Rehearsal Puts NASA’s OSIRIS-REx on a Path to Sample Collection

    August 12, 2020 -

    NASA’s first asteroid-sampling spacecraft just completed its second successful sample collection rehearsal and is now ready for the main event – touching down on asteroid Bennu’s surface in October. Yesterday, the OSIRIS-REx spacecraft performed its final practice run of the sampling sequence, reaching an approximate altitude of 131 feet (40 meters) over sample site Nightingale before executing a back-away burn. Nightingale, OSIRIS-REx’s primary sample collection site, is located within a crater in Bennu’s northern hemisphere.

    Captured on Aug. 11 during the second rehearsal of the OSIRIS-REx mission’s sample collection event, this series of images shows the SamCam imager’s field of view as the NASA spacecraft approaches asteroid Bennu’s surface. The rehearsal brought the spacecraft through the first three maneuvers of the sampling sequence to a point approximately 131 feet (40 meters) above the surface, after which the spacecraft performed a back-away burn. Credit: NASA/Goddard/University of Arizona

    The approximately four-hour “Matchpoint” rehearsal took the spacecraft through the first three of the sampling sequence’s four maneuvers: the orbit departure burn, the “Checkpoint” burn and the Matchpoint burn. Checkpoint is the point where the spacecraft autonomously checks its position and velocity before adjusting its trajectory down toward the event’s third maneuver. Matchpoint is the moment when the spacecraft matches Bennu’s rotation in order to fly in tandem with the asteroid surface, directly above the sample site, before touching down on the targeted spot.

    Four hours after departing its 0.6-mile (1-km) safe-home orbit, OSIRIS-REx performed the Checkpoint maneuver at an approximate altitude of 410 feet (125 meters) above Bennu’s surface. From there, the spacecraft continued to descend for another eight minutes to perform the Matchpoint burn. After descending on this new trajectory for another three minutes, the spacecraft reached an altitude of approximately 131 ft (40 m) – the closest the spacecraft has ever been to Bennu – and then performed a back-away burn to complete the rehearsal.

    During the rehearsal, the spacecraft successfully deployed its sampling arm, the Touch-And-Go Sample Acquisition Mechanism (TAGSAM), from its folded, parked position out to the sample collection configuration. Additionally, some of the spacecraft’s instruments collected science and navigation images and made spectrometry observations of the sample site, as will occur during the sample collection event. These images and science data were downlinked to Earth after the event’s conclusion.

    Because the spacecraft and Bennu are currently about 179 million miles (288 million km) from Earth, it takes approximately 16 minutes for the spacecraft to receive the radio signals used to command it. This time lag prevented live commanding of flight activities from the ground during the rehearsal. As a result, the spacecraft performed the entire rehearsal sequence autonomously. Prior to the rehearsal’s start, the OSIRIS-REx team uplinked all of the event’s commands to the spacecraft and then provided the “Go” command to begin the event. The actual sample collection event in October will be conducted the same way.

    This second rehearsal provided the mission team with practice navigating the spacecraft through the first three maneuvers of the sampling event and with an opportunity to verify that the spacecraft’s imaging, navigation and ranging systems operated as expected during the first part of the descent sequence.

    Matchpoint rehearsal also confirmed that OSIRIS-REx’s Natural Feature Tracking (NFT) guidance system accurately estimated the spacecraft’s trajectory after the Matchpoint burn, which is the final maneuver before the sample collection head contacts Bennu’s surface. This rehearsal was also the first time that the spacecraft’s on-board hazard map was employed. The hazard map delineates areas that could potentially harm the spacecraft. If the spacecraft detects that it is on course to touch a hazardous area, it will autonomously back-away once it reaches an altitude of 16 ft (5 m). While OSIRIS-REx did not fly that low during the rehearsal, it did employ the hazard map to assess whether its predicted touchdown trajectory would have avoided surface hazards, and found that the spacecraft’s path during the rehearsal would have allowed for a safe touchdown on sample site Nightingale.

    During the last minutes of the spacecraft’s descent, OSIRIS-REx also collected new, high-resolution navigation images for the NFT guidance system. These detailed images of Bennu’s landmarks will be used for the sampling event, and will allow the spacecraft to accurately target a very small area.

    “Many important systems were exercised during this rehearsal – from communications, spacecraft thrusters, and most importantly, the onboard Natural Feature Tracking guidance system and hazard map,” said OSIRIS-REx principal investigator Dante Lauretta of the University of Arizona, Tucson. “Now that we’ve completed this milestone, we are confident in finalizing the procedures for the TAG event. This rehearsal confirmed that the team and all of the spacecraft’s systems are ready to collect a sample in October.”

    The mission team has spent the last several months preparing for Matchpoint rehearsal while maximizing remote work as part of the COVID-19 response. On the day of rehearsal, a limited number of personnel monitored the spacecraft’s telemetry from Lockheed Martin Space’s facility, NASA’s Goddard Space Flight Center and the University of Arizona, taking appropriate safety precautions, while the rest of the team performed their roles remotely.

    The spacecraft will travel all the way to the asteroid’s surface during its first sample collection attempt, scheduled for Oct. 20. During this event, OSIRIS-REx’s sampling mechanism will touch Bennu’s surface for several seconds, fire a charge of pressurized nitrogen to disturb the surface and collect a sample before the spacecraft backs away. The spacecraft is scheduled to return the sample to Earth on Sept. 24, 2023.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and provides flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  2. NASA’s OSIRIS-REx Is One Rehearsal Away from Touching Asteroid Bennu

    August 6, 2020 -

    NASA’s first asteroid sampling spacecraft is making final preparations to grab a sample from asteroid Bennu’s surface. Next week, the OSIRIS-REx mission will conduct a second rehearsal of its touchdown sequence, practicing the sample collection activities one last time before touching down on Bennu this fall.

    This artist’s concept shows the trajectory and configuration of NASA’s OSIRIS-REx spacecraft during Matchpoint rehearsal, which is the final time the mission will practice the initial steps of the sample collection sequence before touching down on asteroid Bennu. Credit: NASA/Goddard/University of Arizona

    On Aug. 11, the mission will perform its “Matchpoint” rehearsal – the second practice run of the Touch-and-Go (TAG) sample collection event. The rehearsal will be similar to the Apr. 14 “Checkpoint” rehearsal, which practiced the first two maneuvers of the descent, but this time the spacecraft will add a third maneuver, called the Matchpoint burn, and fly even closer to sample site Nightingale – reaching an altitude of approximately 131 ft (40 m) – before backing away from the asteroid.

    This second rehearsal will be the first time the spacecraft executes the Matchpoint maneuver to then fly in tandem with Bennu’s rotation. The rehearsal also gives the team a chance to become more familiar navigating the spacecraft through all of the descent maneuvers, while verifying that the spacecraft’s imaging, navigation and ranging systems operate as expected during the event.

    During the descent, the spacecraft fires its thrusters three separate times to make its way down to the asteroid’s surface. The spacecraft will travel at an average speed of around 0.2 mph (0.3 kph) during the approximately four-hour excursion. Matchpoint rehearsal begins with OSIRIS-REx firing its thrusters to leave its 0.5-mile (870-m) safe-home orbit. The spacecraft then extends its robotic sampling arm – the Touch-And-Go Sample Acquisition Mechanism (TAGSAM) – from its folded, parked position out to the sample collection configuration. Immediately following, the spacecraft rotates to begin collecting navigation images for the Natural Feature Tracking (NFT) guidance system. NFT allows OSIRIS-REx to autonomously navigate to Bennu’s surface by comparing an onboard image catalog with the real-time navigation images taken during descent. As the spacecraft approaches the surface, the NFT system updates the spacecraft’s predicted point of contact depending on OSIRIS-REx’s position in relation to Bennu’s landmarks.

    The spacecraft’s two solar panels then move into a “Y-wing” configuration that safely positions them up and away from the asteroid’s surface. This configuration also places the spacecraft’s center of gravity directly over the TAGSAM collector head, which is the only part of the spacecraft that will contact Bennu’s surface during the sample collection event.

    When OSIRIS-REx reaches an altitude of approximately 410 ft (125 m), it performs the Checkpoint burn and descends more steeply toward Bennu’s surface for another eight minutes. At approximately 164 ft (50 m) above the asteroid, the spacecraft fires its thrusters a third time for the Matchpoint burn. This maneuver slows the spacecraft’s rate of descent and adjusts its trajectory to match Bennu’s rotation as the spacecraft makes final corrections to target the touchdown spot. OSIRIS-REx will continue capturing images of Bennu’s landmarks for the NFT system to update the spacecraft’s trajectory for another three minutes of descent. This brings OSIRIS-REx to its targeted destination around 131 ft (40 m) from Bennu – the closest it has ever been to the asteroid. With the rehearsal complete, the spacecraft executes a back-away burn, returns its solar panels to their original position and reconfigures the TAGSAM arm back to the parked position.

    During the rehearsal, the one-way light time for signals to travel between Earth and the spacecraft will be approximately 16 minutes, which prevents the live commanding of flight activities from the ground. So prior to the rehearsal’s start, the OSIRIS-REx team will uplink all of the event’s commands to the spacecraft, allowing OSIRIS-REx to perform the rehearsal sequence autonomously after the GO command is given. Also during the event, the spacecraft’s low gain antenna will be its only antenna pointing toward Earth, transmitting data at the very slow rate of 40 bits per second. So while the OSIRIS-REx team will be able to monitor the spacecraft’s vital signs, the images and science data collected during the event won’t be downlinked until the rehearsal is complete. The team will experience these same circumstances during the actual TAG event in October.

    Following Matchpoint rehearsal, the OSIRIS-REx team will verify the flight system’s performance during the descent, including that the Matchpoint burn accurately adjusted the spacecraft’s descent trajectory for its touchdown on Bennu. Once the mission team determines that OSIRIS-REx operated as expected, they will command the spacecraft to return to its safe-home orbit around Bennu.

    The mission team has spent the last several months preparing for the Matchpoint rehearsal while maximizing remote work as part of its COVID-19 response. On the day of rehearsal, a limited number of personnel will monitor the spacecraft from Lockheed Martin Space’s facility, taking appropriate safety precautions, while the rest of the team performs their roles remotely. The mission implemented a similar protocol during the Checkpoint rehearsal in April.

    On Oct. 20, the spacecraft will travel all the way to the asteroid’s surface during its first sample collection attempt. During this event, OSIRIS-REx’s sampling mechanism will touch Bennu’s surface for approximately five seconds, fire a charge of pressurized nitrogen to disturb the surface and collect a sample before the spacecraft backs away. The spacecraft is scheduled to return the sample to Earth on Sept. 24, 2023.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  3. NASA’s OSIRIS-REx Discovers Sunlight Can Crack Rocks on Asteroid Bennu

    June 9, 2020 -

    Asteroids don’t just sit there doing nothing as they orbit the Sun. They get bombarded by meteoroids, blasted by space radiation, and now, for the first time, scientists are seeing evidence that even a little sunshine can wear them down.

    Rocks on asteroid Bennu appear to be cracking as sunlight heats them up during the day and they cool down at night, according to images from NASA’s OSIRIS-REx (Origins Spectral Interpretation Resource Identification Security – Regolith Explorer) spacecraft.

    This image shows a group of large boulders located just north of asteroid Bennu’s equatorial region. The boulder in the lower right shows evidence of exfoliation, where thermal fracturing likely caused small, thin layers to flake off of the boulder’s surface. Credit: NASA/Goddard/University of Arizona

    “This is the first time evidence for this process, called thermal fracturing, has been definitively observed on an object without an atmosphere,” said Jamie Molaro of the Planetary Science Institute, Tucson, Arizona, lead author of a paper appearing in Nature Communications June 9. “It is one piece of a puzzle that tells us what the surface used to be like, and what it will be like millions of years from now.”

    “Like any weathering process, thermal fracturing causes the evolution of boulders and planetary surfaces over time – from changing the shape and size of individual boulders, to producing pebbles or fine-grained regolith, to breaking down crater walls,” said OSIRIS-REx principal investigator Dante Lauretta of the University of Arizona, Tucson. “How quickly this occurs relative to other weathering processes tells us how and how quickly the surface has changed.”

    Rocks expand when sunlight heats them during the day and contract as they cool down at night, causing stress that forms cracks that grow slowly over time. Scientists have thought for a while that thermal fracturing could be an important weathering process on airless objects like asteroids because many experience extreme temperature differences between day and night, compounding the stress. For example, daytime highs on Bennu can reach almost 127 degrees Celsius or about 260 degrees Fahrenheit, and nighttime lows plummet to about minus 73 degrees Celsius or nearly minus 100 degrees Fahrenheit. However, many of the telltale features of thermal fracturing are small, and before OSIRIS-REx got close to Bennu, the high-resolution imagery required to confirm thermal fracturing on asteroids didn’t exist.

    The mission team found features consistent with thermal fracturing using the spacecraft’s OSIRIS-REx Camera Suite (OCAMS), which can see features on Bennu smaller than one centimeter (almost 0.4 inches). It found evidence of exfoliation, where thermal fracturing likely caused small, thin layers (1 – 10 centimeters) to flake off of boulder surfaces. The spacecraft also produced images of cracks running through boulders in a north-south direction, along the line of stress that would be produced by thermal fracturing on Bennu.

    Other weathering processes can produce similar features, but the team’s analysis ruled them out. For example, rain and chemical activity can produce exfoliation, but Bennu has no atmosphere to produce rain. Rocks squeezed by tectonic activity can also exfoliate, but Bennu is too small for such activity. Meteoroid impacts do occur on Bennu and can certainly crack rocks, but they would not cause the even erosion of layers from boulder surfaces that were seen. Also, there’s no sign of impact craters where the exfoliation is occurring.

    Additional studies of Bennu could help determine how rapidly thermal fracturing is wearing down the asteroid, and how it compares to other weathering processes. “We don’t have good constraints yet on breakdown rates from thermal fracturing, but we can get them now that we can actually observe it for the first time in situ,” said OSIRIS-REx project scientist Jason Dworkin of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Laboratory measurements on the properties of the samples returned by the spacecraft in 2023 will help us learn more about how this process works.”

    Another area of research is how thermal fracturing affects our ability to estimate the age of surfaces. In general, the more weathered a surface is, the older it is. For example, a region with a lot of craters is likely to be older than an area with few craters, assuming impacts happen at a relatively constant rate across an object. However, additional weathering from thermal fracturing could complicate an age estimate, because thermal fracturing is going to happen at a different rate on different bodies, depending on things like their distance from the Sun, the length of their day, and the composition, structure and strength of their rocks. On bodies where thermal fracturing is efficient, then it may cause crater walls to break down and erode faster. This would make the surface look older according the cratering record, when in fact it is actually younger. Or the opposite could occur. More research on thermal fracturing on different bodies is needed to start to get a handle on this, according to Molaro.

    The research was funded by NASA’s OSIRIS-REx Participating Scientist program as well as the OSIRIS-REx mission. NASA’s Goddard Space Flight Center in Greenbelt, Maryland provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington. NASA is exploring our Solar System and beyond, uncovering worlds, stars, and cosmic mysteries near and far with our powerful fleet of space and ground-based missions.

  4. Asteroids Bennu and Ryugu May Have Formed Directly From Collision in Space

    June 1, 2020 -

    Scientists with NASA’s first asteroid sample return mission, OSIRIS-REx, are gaining a new understanding of asteroid Bennu’s carbon-rich material and signature “spinning-top” shape. The team, led by the University of Arizona, has discovered that the asteroid’s shape and hydration levels provide clues to the origins and histories of this and other small bodies.

    Illustrating what scientists argue in the paper, this animation demonstrates how top-shape asteroids may have formed. This simulation shows the gravitational reaccumulation of an asteroid parent body (center) following its catastrophic disruption by an impact. The movie begins with a change in perspective to display the initial geometry of the impacted 100-km asteroid, followed by the dispersal of fragments to form separate rubble-pile asteroids. The color of each particle indicates the change in its temperature after impact, with blue being no change and dark red indicated a change of 1000 Kelvin.

    Bennu, the target asteroid for the OSIRIS-REx mission, and Ryugu, the target of the Japan Aerospace Exploration Agency’s Hayabusa2 asteroid sample return mission, are composed of fragments of larger bodies that shattered upon colliding with other objects. The small fragments reaccumulated to form an aggregate body. Bennu and Ryugu may actually have formed in this way from the same original shattered parent body. Now, scientists are looking to discover what processes led to specific characteristics of these asteroids, such as their shape and mineralogy.

    Bennu and Ryugu are both classified as “spinning-top” asteroids, which means they have a pronounced equatorial ridge. Until now, scientists thought that this shape formed as the result of thermal forces, called the YORP effect. The YORP effect increases the speed of the asteroid’s spin, and over millions of years, material near the poles could have migrated to accumulate on the equator, eventually forming a spinning-top shape – meaning that the shape would have formed relatively recently.

    However, in a new paper published in Nature Communications, scientists from the OSIRIS-REx and Hayabusa2 teams argue that the YORP effect may not explain the shape of either Bennu or Ryugu. Both asteroids have large impact craters on their equators, and their size suggests that these craters are some of Bennu’s oldest surface features. Since the craters cover the equatorial ridges, their spinning-top shapes must also have been formed much earlier.

    “Using computer simulations that model the impact that broke up Bennu’s parent body, we show that these asteroids either formed directly as top-shapes, or achieved the shape early after their formation in the main asteroid belt,” said Ronald Ballouz, co-lead author and OSIRIS-REx postdoctoral research associate at the UArizona. “The presence of the large equatorial craters on these asteroids, as seen in images returned by the spacecraft, rules out that the asteroids experienced a recent re-shaping due to the YORP effect. We would expect these craters to have disappeared with a recent YORP-induced re-shaping of the asteroid.”

    In addition to their shapes, Bennu and Ryugu also both contain water-bearing surface material in the form of clay minerals. Ryugu’s surface material is less water-rich than Bennu’s, which implies that Ryugu’s material experienced more heating at some point.

    This image shows asteroid Bennu’s spinning top shape. It was taken by the MapCam camera on NASA’s OSIRIS-REx spacecraft on April 29, from a distance of 5 miles (8 km). From the spacecraft’s vantage point, half of Bennu is sunlit and half is in shadow. The asteroid is 1,673 ft (510 m) in height – a bit taller than the Empire State Building.

    Assuming Bennu and Ryugu formed simultaneously, the paper explores two possible explanations for the different hydration levels of the two bodies based on the team’s computer simulations. One hypothesis suggests that when the parent asteroid was disrupted, Bennu formed from material closer to the original surface, while Ryugu contained more material from near the parent body’s original center. Another possible explanation for the difference in hydration levels is that the fragments experienced different levels of heating during the parent asteroid’s disruption. If this is the case, Ryugu’s source material is likely from an area near the impact point, where temperatures were higher. Bennu’s material would have come from a region that didn’t undergo as much heating, and was likely farther from the point of impact. Analysis of the returned samples and further observational analysis of the asteroids’ surfaces will provide a clearer idea of the possible shared history of the two asteroids.

    “These simulations provide valuable new insights into how Bennu and Ryugu formed,” said Dante Lauretta, OSIRIS-REx principal investigator and UArizona professor of planetary sciences. “Once we have the returned samples of these two asteroids in the lab, we may be able to further confirm these models, possibly revealing the true relationship between the two asteroids.”

    Scientists anticipate that the samples will also provide new insights into the origins, formation and evolution of other carbonaceous asteroids and meteorites. The Japan Aerospace Exploration Agency’s Hayabusa2 mission is currently making its way back to Earth, and is scheduled to deliver its samples of Ryugu late this year. The OSIRIS-REx mission will perform its first sample collection attempt at Bennu on Oct. 20 and will deliver its samples to Earth on Sep. 24, 2023.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and provides flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  5. OSIRIS-REx Performs Closest Flyover of Sample Site Osprey

    May 27, 2020 -

    NASA’s first asteroid-sampling spacecraft has had another close encounter with asteroid Bennu. Yesterday, NASA’s OSIRIS-REx spacecraft executed its lowest pass yet over sample site Osprey, taking observations from an altitude of 820 feet (250 m). Osprey, OSIRIS-REx’s backup sample collection site, is located within a crater just north of Bennu’s equator.

    To perform the five-hour flyover, the spacecraft left its 0.6-mile (1-km) counterclockwise orbit (as viewed from the Sun) and aimed its science instruments toward the 52-ft (16-m) wide site. The science observations from this pass are the closest taken of Osprey to date. In March, the spacecraft executed a similar pass over primary sample site Nightingale.

    A primary goal of the low flyover was to collect high-resolution imagery of the site’s surface material. The spacecraft’s sample collection mechanism is designed to pick up rocks smaller than 0.8 inches (2 cm), and the detailed PolyCam images from yesterday’s low pass will allow the team to identify rocks of this size.

    The flyover also provided the opportunity to capture images for the Natural Feature Tracking (NFT) image catalog for site Osprey – documenting the site’s surface features. If the mission decides to collect a sample from backup site Osprey, the spacecraft will use this NFT image catalog to autonomously navigate down to Bennu’s surface. The mission originally planned to collect this imagery during a 0.4-mile (620-m) flyover in February, but the images from that pass are out of focus due to an anomaly in the low energy laser transmitter (LELT) subsystem with the OSIRIS-REx Laser Altimeter (OLA), which was providing range measurements to focus PolyCam. OLA’s high energy laser transmitter (HELT) was used in this most recent Osprey flyover, as was done in a similar flyover of the Nightingale site.

    Several of the spacecraft’s other instruments also took observations of the Osprey site during the flyover event, including the OSIRIS-REx Thermal Emissions Spectrometer (OTES), the OSIRIS-REx Visual and InfraRed Spectrometer (OVIRS), and the OSIRIS-REx Laser Altimeter (OLA).

    After completing the pass, OSIRIS-REx returned to its safe-home orbit and is now circling Bennu clockwise. The spacecraft normally orbits Bennu counterclockwise, but this shift in orbital direction was necessary to position the spacecraft for its next close encounter with the asteroid – the second rehearsal for the sample collection event.

    The mission successfully executed the first sample-collection rehearsal on Apr. 14, completing a practice run of some of the activities leading up to the sampling event and bringing the spacecraft 213 ft (65 m) from the asteroid’s surface. The second rehearsal, scheduled for Aug. 11, will bring the spacecraft through the first three maneuvers of the sample collection sequence to an approximate altitude of 131 ft (40 m) over the surface of Bennu.

    The spacecraft will attempt to venture all the way to the asteroid’s surface on Oct. 20, for its first attempt to collect a sample from site Nightingale. During this event, OSIRIS-REx’s sampling mechanism will touch Bennu and fire a charge of pressurized nitrogen to disturb the surface and collect its sample before the spacecraft backs away.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and provides flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  6. NASA’s OSIRIS-REx Ready for Touchdown on Asteroid Bennu

    May 20, 2020 -

    NASA’s first asteroid sample return mission is officially prepared for its long-awaited touchdown on asteroid Bennu’s surface. The Origins, Spectral Interpretation, Resource Identification and Security – Regolith Explorer (OSIRIS-REx) mission has targeted Oct. 20 for its first sample collection attempt.

    This artist’s concept shows NASA’s OSIRIS-REx spacecraft descending towards asteroid Bennu to collect a sample of the asteroid’s surface. Credit: NASA/Goddard/University of Arizona

    “The OSIRIS-REx mission has been demonstrating the very essence of exploration by persevering through unexpected challenges,” said Thomas Zurbuchen, NASA’s associate administrator for science. “That spirit has led them to the cusp of the prize we all are waiting for – securing a sample of an asteroid to bring home to Earth, and I’m very excited to follow them through the home stretch.”

    From discovering Bennu’s surprisingly rugged and active surface, to entering the closest-ever orbit around a planetary body, OSIRIS-REx has overcome several challenges since arriving at the asteroid in December 2018. Last month, the mission brought the spacecraft 213 ft (65 m) from the asteroid’s surface during its first sample collection rehearsal — successfully completing a practice run of the activities leading up to the sampling event.

    Now that the mission is ready to collect a sample, the team is facing a different kind of challenge here on Earth. In response to COVID-19 constraints and after the intense preparation for the first rehearsal, the OSIRIS-REx mission has decided to provide its team with additional preparation time for both the final rehearsal and the sample collection event. Spacecraft activities require significant lead time for the development and testing of operations, and given the current requirements that limit in-person participation at the mission support area, the mission would benefit from giving the team additional time to complete these preparations in the new environment. As a result, both the second rehearsal and first sample collection attempt will have two extra months for planning.

    “In planning the mission, we included robust schedule margin while at Bennu to provide the flexibility to address unexpected challenges,” said Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center. “This flexibility has allowed us to adapt to the surprises that Bennu has thrown at us. It’s now time to prioritize the health and safety of both team members and the spacecraft.”

    The mission had originally planned to perform the first Touch-and-Go (TAG) sample collection event on Aug. 25 after completing a second rehearsal in June. This rehearsal, now scheduled for Aug. 11, will bring the spacecraft through the first three maneuvers of the sample collection sequence to an approximate altitude of 131 ft (40 m) over the surface of Bennu. The first sample collection attempt is now scheduled for Oct. 20, during which the spacecraft will descend to Bennu’s surface and collect material from sample site Nightingale.

    “This mission’s incredible performance so far is a testament to the extraordinary skill and dedication of the OSIRIS-REx team,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “I am confident that even in the face of the current challenge, this team will be successful in collecting our sample from Bennu.”

    During the TAG event, OSIRIS-REx’s sampling mechanism will touch Bennu’s surface for approximately five seconds, fire a charge of pressurized nitrogen to disturb the surface, and collect a sample before the spacecraft backs away. The mission has resources onboard for three sample collection opportunities. If the spacecraft successfully collects a sufficient sample on Oct. 20, no additional sampling attempts will be made. The spacecraft is scheduled to depart Bennu in mid-2021, and will return the sample to Earth on Sept. 24, 2023.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and provides flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  7. One Step Closer to Touching Asteroid Bennu

    April 15, 2020 -

    After the successful completion of its “Checkpoint” rehearsal, NASA’s first asteroid-sampling spacecraft is one step closer to touching down on asteroid Bennu. Yesterday, NASA’s OSIRIS-REx spacecraft performed the first practice run of its sample collection sequence, reaching an approximate altitude of 246 feet (75 meters) over site Nightingale before executing a back-away burn from the asteroid. Nightingale, OSIRIS-REx’s primary sample collection site, is located within a crater in Bennu’s northern hemisphere.

    This artist’s concept shows the trajectory and configuration of NASA’s OSIRIS-REx spacecraft during Checkpoint rehearsal, which was the first time the mission practiced the initial steps of collecting a sample from asteroid Bennu. Credit: NASA/Goddard/University of Arizona

    The four-hour Checkpoint rehearsal took the spacecraft through the first two of the sampling sequence’s four maneuvers: the orbit departure burn and the Checkpoint burn. Checkpoint is so named because it is the location where the spacecraft autonomously checks its position and velocity before adjusting its trajectory down toward the location of the event’s third maneuver.

    Four hours after departing its 0.6-mile (1-km) safe-home orbit, the spacecraft performed the Checkpoint maneuver at an approximate altitude of 410 feet (125 meters) above Bennu’s surface. From there, the spacecraft continued to descend for another nine minutes on a trajectory toward – but not reaching – the location of the sampling event’s third maneuver, the “Matchpoint” burn. Upon reaching an altitude of approximately 246 ft (75 m) – the closest the spacecraft has ever been to Bennu – OSIRIS-REx performed a back-away burn to complete the rehearsal.

    During the rehearsal, the spacecraft successfully deployed its sampling arm, the Touch-And-Go Sample Acquisition Mechanism (TAGSAM), from its folded, parked position out to the sample collection configuration. Additionally, some of the spacecraft’s instruments collected science and navigation images and made spectrometry observations of the sample site, as will occur during the sample collection event.

    This first rehearsal provided the mission team with practice navigating the spacecraft through both the orbit departure and Checkpoint maneuvers and with an opportunity to verify that the spacecraft’s imaging, navigation and ranging systems operated as expected during the first part of the descent sequence. Checkpoint rehearsal also gave the team confirmation that OSIRIS-REx’s Natural Feature Tracking (NFT) guidance system accurately estimated the spacecraft’s position and speed relative to Bennu as it descended toward the surface.

    The mission team has maximized remote work over the last month of preparations for the Checkpoint rehearsal, as part of the COVID-19 response. On the day of rehearsal, a limited number of personnel monitored the spacecraft’s telemetry from Lockheed Martin Space’s facility, NASA’s Goddard Space Flight Center and the University of Arizona, taking appropriate safety precautions, while the rest of the team performed their roles remotely.

    “This rehearsal let us verify flight system performance during the descent, particularly the autonomous update and execution of the Checkpoint burn,” said Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Executing this monumental milestone during this time of national crisis is a testament to the professionalism and focus of our team. It speaks volumes about their ‘can-do’ attitude and hopefully will serve as a bit of good news in these challenging times.”

    The spacecraft will travel all the way to the asteroid’s surface during its first sample collection attempt, scheduled for Aug. 25. During this event, OSIRIS-REx’s sampling mechanism will touch Bennu’s surface for approximately five seconds, fire a charge of pressurized nitrogen to disturb the surface and collect a sample before the spacecraft backs away. The spacecraft is scheduled to return the sample to Earth on Sept. 24, 2023.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and provides flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  8. Rehearsal Time for NASA’s Asteroid Sampling Spacecraft

    April 9, 2020 -

    In August, a robotic spacecraft will make NASA’s first-ever attempt to descend to the surface of an asteroid, collect a sample, and ultimately bring it safely back to Earth. In order to achieve this challenging feat, the OSIRIS-REx mission team devised new techniques to operate in asteroid Bennu’s microgravity environment – but they still need experience flying the spacecraft in close proximity to the asteroid in order to test them. So, before touching down at sample site Nightingale this summer, OSIRIS-REx will first rehearse the activities leading up to the event.

    This artist’s concept shows the trajectory and configuration of NASA’s OSIRIS-REx spacecraft during Checkpoint rehearsal, which is the first time the mission will practice the initial steps for collecting a sample from asteroid Bennu. Credit: NASA/Goddard/University of Arizona

    On Apr. 14, the mission will pursue its first practice run – officially known as “Checkpoint” rehearsal – which will also place the spacecraft the closest it’s ever been to Bennu. This rehearsal is a chance for the OSIRIS-REx team and spacecraft to test the first steps of the robotic sample collection event.

    During the full touchdown sequence, the spacecraft uses three separate thruster firings to make its way to the asteroid’s surface. After an orbit departure burn, the spacecraft executes the Checkpoint maneuver at 410 ft (125 m) above Bennu, which adjusts the spacecraft’s position and speed down toward the point of the third burn. This third maneuver, called “Matchpoint,” occurs at approximately 164 ft (50 m) from the asteroid’s surface and places the spacecraft on a trajectory that matches the rotation of Bennu as it further descends toward the targeted touchdown spot.

    The Checkpoint rehearsal allows the team to practice navigating the spacecraft through both the orbit departure and Checkpoint maneuvers, and ensures that the spacecraft’s imaging, navigation and ranging systems operate as expected during the first part of the descent sequence. Checkpoint rehearsal also gives the team a chance to confirm that OSIRIS-REx’s Natural Feature Tracking (NFT) guidance system accurately updates the spacecraft’s position and velocity relative to Bennu as it descends towards the surface.

    Checkpoint rehearsal, a four-hour event, begins with the spacecraft leaving its safe-home orbit, 0.6 miles (1 km) above the asteroid. The spacecraft then extends its robotic sampling arm – the Touch-And-Go Sample Acquisition Mechanism (TAGSAM) – from its folded, parked position out to the sample collection configuration. Immediately following, the spacecraft slews, or rotates, into position to begin collecting navigation images for NFT guidance. NFT allows the spacecraft to autonomously guide itself to Bennu’s surface by comparing an onboard image catalog with the real-time navigation images taken during descent. As the spacecraft descends to the surface, the NFT system updates the spacecraft’s predicted point of contact depending on OSIRIS-REx’s position in relation to Bennu’s landmarks.

    Before reaching the 410-ft (125-m) Checkpoint altitude, the spacecraft’s solar arrays move into a “Y-wing” configuration that safely positions them away from the asteroid’s surface. This configuration also places the spacecraft’s center of gravity directly over the TAGSAM collector head, which is the only part of the spacecraft that will contact Bennu’s surface during the sample collection event.

    In the midst of these activities, the spacecraft continues capturing images of Bennu’s surface for the NFT navigation system. The spacecraft will then perform the Checkpoint burn and descend toward Bennu’s surface for another nine minutes, placing the spacecraft around 243 ft (75 m) from the asteroid – the closest it has ever been.

    Upon reaching this targeted point, the spacecraft will execute a back-away burn, then return its solar arrays to their original position and reconfigure the TAGSAM arm back to the parked position. Once the mission team determines that the spacecraft successfully completed the entire rehearsal sequence, they will command the spacecraft to return to its safe-home orbit around Bennu.

    Following the Checkpoint rehearsal, the team will verify the flight system’s performance during the descent, and that the Checkpoint burn accurately adjusted the descent trajectory for the subsequent Matchpoint burn.

    The mission team has maximized remote work over the last month of preparations for the checkpoint rehearsal, as part of the COVID-19 response. On the day of rehearsal, a limited number of personnel will command the spacecraft from Lockheed Martin Space’s facility, taking appropriate safety precautions, while the rest of the team performs their roles remotely.

    The mission is scheduled to perform a second rehearsal on Jun. 23, taking the spacecraft through the Matchpoint burn and down to an approximate altitude of 82 ft (25 m). OSIRIS-REx’s first sample collection attempt is scheduled for Aug. 25.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  9. Bennu’s Boulders Shine as Beacons for NASA’s OSIRIS-REx

    March 9, 2020 -

    This summer, the OSIRIS-REx spacecraft will undertake NASA’s first-ever attempt to touch the surface of an asteroid, collect a sample of it, and safely back away. But since arriving at asteroid Bennu over a year ago, the mission team has been tackling an unexpected challenge: how to accomplish this feat at an asteroid whose surface is blanketed in building-sized boulders.

    During the sample collection event, Natural Feature Tracking (NFT) will guide NASA’s OSIRIS-REx spacecraft to asteroid Bennu’s surface. The spacecraft takes real-time images of the asteroid’s surface features as it descends, and then compares these images with an onboard image catalog. The spacecraft then uses these geographical markers to orient itself and accurately target the touchdown site. Credit: NASA/Goddard/University of Arizona

    Using these hazardous boulders as signposts, the mission team developed a new precision navigation method to overcome the challenge.

    The OSIRIS-REx team had originally planned to use a LIDAR system to navigate to Bennu’s surface during the Touch-And-Go (TAG) sample collection event. LIDAR is similar to radar, but it uses laser pulses rather than radio waves to measure distance. The OSIRIS-REx Guidance, Navigation, and Control (GNC) LIDAR is designed to navigate the spacecraft to a relatively hazard-free surface. The mission had originally envisioned a touchdown site 164 ft (50 meters) in diameter, but the largest safe areas on Bennu are much smaller. The biggest site is just 52 ft (16 m) wide, or roughly 10% of the safe area envisioned. The team realized that they needed a more precise navigation technique that would allow the spacecraft to accurately target very small sites while dodging potential hazards.

    In the face of this challenge, the OSIRIS-REx team switched to a new navigation method called Natural Feature Tracking (NFT). NFT provides more extensive navigation capabilities than LIDAR, and is key for executing what the team is calling “Bullseye TAG,” which delivers the spacecraft to the much smaller sampling area. As an optical navigation technique, it requires the creation of a high-resolution image catalog onboard the spacecraft.

    Earlier this year, the spacecraft made reconnaissance passes over the mission’s primary and backup sample collection sites, designated Nightingale and Osprey, flying as close as 0.4 miles (625 m) over the surface. During these flyovers, the spacecraft collected images from different angles and lighting conditions to complete the NFT image catalog. The team uses this catalog to identify boulders and craters unique to the sample site region, and will upload this information to the spacecraft before the sample collection event. NFT autonomously guides the spacecraft to Bennu’s surface by comparing the onboard image catalog with the real-time navigation images taken during descent. As the spacecraft descends to the surface, NFT updates its predicted point of contact depending on the spacecraft’s position in relation to the landmarks.

    On the ground, team members created “hazard maps” for both the Nightingale and Osprey sites to document all of the surface features that could potentially harm the spacecraft, like large rocks or steep slopes. The team used the image catalog in conjunction with data from the OSIRIS-REx Laser Altimeter (OLA) to create 3D maps that closely model Bennu’s topography. As part of NFT, these maps document boulder heights and crater depths, and guide the spacecraft away from potential hazards while targeting a very small site. During descent, if the spacecraft predicts it will touch unsafe terrain, it will autonomously wave-off and back away from the surface. However, if it sees that the area is free of hazards, it will continue to descend and attempt to collect a sample.

    During sample collection, Natural Feature Tracking (NFT) will guide NASA’s OSIRIS-REx spacecraft to asteroid Bennu’s surface. Hazard maps are also part of the NFT guidance system – they document boulder heights and crater depths, and guide the spacecraft away from potential hazards. Credit: NASA/Goddard/University of Arizona

    NFT will be used in April to navigate the spacecraft during its first sample collection rehearsal. The operations team performed preliminary testing during the Orbital B mission phase in late 2019, and the results demonstrated that NFT works in real-life conditions as designed. NFT will also be used for navigation during the second rehearsal planned for June.

    OSIRIS-REx’s first sample collection attempt is scheduled for late August. The spacecraft will depart Bennu in 2021 and is scheduled to deliver the sample to Earth in September 2023.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and provides flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  10. First Official Names Given to Features on Asteroid Bennu

    March 6, 2020 -

    Asteroid Bennu’s most prominent boulder, a rock chunk jutting out 71 ft (21.7 m) from the asteroid’s southern hemisphere, finally has a name. The boulder – which is so large that it was initially detected from Earth – is officially designated Benben Saxum after the primordial hill that first arose from the dark waters in an ancient Egyptian creation myth.

    This flat projection mosaic of asteroid Bennu shows the locations of the first 12 surface features to receive official names from the International Astronomical Union. The accepted names were proposed by NASA’s OSIRIS-REx team members, who have been mapping the asteroid in detail over the last year. Bennu’s surface features are named after birds and bird-like creatures in mythology, and the places associated with them. Credit: NASA/Goddard/University of Arizona

    Benben Saxum and 11 other features on the asteroid are the first to receive official Bennu feature names approved by the International Astronomical Union (IAU), the internationally recognized authority for naming celestial bodies and their surface features. The accepted names were proposed by NASA’s OSIRIS-REx team members, who have been mapping the asteroid in detail over the last year. The OSIRIS-REx spacecraft, NASA’s first asteroid sample return mission, is currently visiting the asteroid and is scheduled to collect a sample from Bennu’s surface this summer.

    “Since arriving at the asteroid, the OSIRIS-REx team has become incredibly familiar with all of the geological features on Bennu,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “These features are providing us with insight into Bennu’s history, and their new names symbolize the essence of the mission – studying the past to both discover our origins and understand our future,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson.

    The approved Bennu surface feature names are listed below. Bennu’s diverse terrain types – including regiones (broad geographic regions), craters, dorsa (ridges), fossae (grooves or trenches) and saxa (rocks and boulders) – will be named after birds and bird-like creatures in mythology, and the places associated with them.

     

    Credit: NASA/Goddard/University of Arizona

    Tlanuwa Regio is named for the giant birds who scattered the Earth with pieces of a serpent that turned into standing pillars of rocks in Cherokee mythology. Tlanuwa Regio is an area covered by large boulders in Bennu’s southern hemisphere.

     

     

     

     

     

     

    Credit: NASA/Goddard/University of Arizona

    Benben Saxum is named for an ancient Egyptian mound that arose from the primordial waters Nu. In Egyptian mythology, the god Atum settled upon Benben to create the world after his flight over the waters in the form of the Bennu bird. Benben Saxum is the tallest boulder on Bennu.

     

     

     

     

     

     

    Credit: NASA/Goddard/University of Arizona

    Roc Saxum is named for the Roc, an enormous bird of prey in Arabian mythology of the Middle East. Roc Saxum is the largest boulder feature on Bennu.

     

     

     

     

     

     

     

    Credit: NASA/Goddard/University of Arizona

    Simurgh Saxum is named for the benevolent, mythological bird in Persian mythology. The Simurgh was said to possess all knowledge, and Simurgh Saxum defines the prime meridian on Bennu and is the basis for the asteroid’s coordinate system.

     

     

     

     

     

     

     

     

    Credit: NASA/Goddard/University of Arizona

    Huginn Saxum and Muninn Saxum are adjacent boulders named for the two ravens, Huginn and Muninn, who accompany the god Odin in Norse mythology.

     

     

     

     

     

     

     

     

     

    Credit: NASA/Goddard/University of Arizona

    Ocypete Saxum is named for one of the Greek harpies, the half-maiden and half-bird personification of storm winds that would snatch and carry things away from Earth. Ocypete Saxum is located near the origin of the Jan. 19, 2019, particle ejection event on Bennu.

     

     

     

     

     

     

    Credit: NASA/Goddard/University of Arizona

    Strix Saxum is named for the Strix bird of ill-omen from Roman mythology. Strix Saxum is a large boulder flanking the OSIRIS-REx mission’s backup sample collection site.

     

     

     

     

     

     

     

     

     

    Credit: NASA/Goddard/University of Arizona

    Amihan Saxum is named for the Tagalog (Philippines) mythological deity, who is depicted as a bird and was the first creature to inhabit the universe. This large, flat boulder appears to be partly buried and is located in Tlanuwa Regio, which has an unusually high concentration of large boulders.

     

     

     

     

     

     

    Credit: NASA/Goddard/University of Arizona

    Pouakai Saxum is named for the monstrous bird who kills and eat humans in Māori (Polynesia) mythology. Pouakai Saxum is a 55 ft (10.6 m)-wide boulder located in Bennu’s southern hemisphere, slightly north of Benben Saxum.

     

     

     

     

     

     

     

     

    Credit: NASA/Goddard/University of Arizona

    Aetos Saxum is named for the childhood playmate of the supreme god Zeus, who was turned into an eagle by Hera in Greek mythology. Aetos Saxum is a conspicuously flat boulder, with a general wing-like shape located near Bennu’s equator.

     

     

     

     

     

     

     

     

    Credit: NASA/Goddard/University of Arizona

    Gargoyle Saxum is named for the French dragon-like monster with wings, bird-like neck, and the ability to breathe fire. Gargoyle Saxum is a large prominent boulder near the mission’s backup sample site that is one of the darkest objects on the surface.

     

     

     

     

     

     

     

     

     

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  11. OSIRIS-REx Swoops Over Sample Site Nightingale

    March 4, 2020 -

    NASA’s first asteroid-sampling spacecraft just got its best look yet at asteroid Bennu. Yesterday, the OSIRIS-REx spacecraft executed a very low pass over sample site Nightingale, taking observations from an altitude of 820 feet (250 m), which is the closest that OSIRIS-REx has flown over the asteroid so far. Nightingale, OSIRIS-REx’s primary sample collection site, is located within a crater in Bennu’s northern hemisphere.

    On Mar. 3, the OSIRIS-REx spacecraft performed a low-altitude flyover of site Nightingale. During the pass, science observations of asteroid Bennu took place from a distance of approximately 820 ft (250 m) – the closest the spacecraft has ever been to the asteroid’s surface. Credit: University of Arizona

    To perform the 5-hour flyover, the spacecraft left its 0.6-mile (1-km) safe-home orbit and aimed its science instruments toward the 52-ft (16-m) wide sample site. The science observations from this pass are the closest taken of Bennu to date.

    The main goal of yesterday’s low flyover was to collect high-resolution imagery of the site’s surface material. The spacecraft’s sample collection mechanism is designed to pick up small rocks less than 0.8 inches (2 cm) in size, and the PolyCam images from this low pass are very detailed, allowing the team to identify and locate rocks of this size. Several of the spacecraft’s other instruments also took observations of the Nightingale site during the flyover event, including the OSIRIS-REx Thermal Emissions Spectrometer (OTES), the OSIRIS-REx Visual and InfraRed Spectrometer (OVIRS), the OSIRIS-REx Laser Altimeter (OLA), and the MapCam color imager.

    After completing the flyover, the spacecraft returned to orbit – but for the first time, OSIRIS-REx reversed the direction of its safe-home orbit and is now circling Bennu clockwise (as viewed from the Sun). This shift in orbital direction positioned the spacecraft for its next close encounter with the asteroid – its first rehearsal for the sample collection event.

    This spring, the mission will perform two rehearsals in preparation for the sample collection event. The first rehearsal, scheduled for Apr. 14, navigates the spacecraft down to 410 feet (125 m) over Bennu’s surface. At this altitude, the spacecraft will execute the Checkpoint maneuver, designed to put the spacecraft on a descent trajectory toward the sample collection site on the surface. The spacecraft will stop its descent ten minutes later at an altitude of approximately 164 ft (50 m) by executing a maneuver to back away from the asteroid. The second rehearsal, scheduled for June, follows the same trajectory but takes the spacecraft to a lower altitude of 164 feet (50 m), where it will perform the Matchpoint maneuver, designed to slow the spacecraft’s descent rate. Subsequent to this burn the spacecraft will execute a back away maneuver between 131 ft (40 m) and 82 ft (25 m) from Bennu’s surface. The spacecraft will venture all the way to the asteroid’s surface in late August, for its first attempt to collect a sample. During this event, OSIRIS-REx’s sampling mechanism will touch Bennu’s surface and fire a charge of pressurized nitrogen to disturb the surface and collect its sample before the spacecraft backs away.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and provides flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  12. NASA’s OSIRIS-REx Students Catch Unexpected Glimpse of Newly Discovered Black Hole

    February 28, 2020 -

    University students and researchers working on a NASA mission orbiting a near-Earth asteroid have made an unexpected detection of a phenomenon 30 thousand light years away. Last fall, the student-built Regolith X-Ray Imaging Spectrometer (REXIS) onboard NASA’s OSIRIS-REx spacecraft detected a newly flaring black hole in the constellation Columba while making observations off the limb of asteroid Bennu.

    This visualization simulates an X-ray outburst from the black hole MAXI J0637-043, detected by the REXIS instrument on NASA’s OSIRIS-REx spacecraft, as it moves through REXIS’s line of sight. At first, the outburst is visibly intense, but it gradually fades as it subsides. The animation was constructed using data collected by the X-ray spectrometer while REXIS was making observations of the space around asteroid Bennu on Nov. 11, 2019. Credit: NASA/Goddard/University of Arizona/MIT/Harvard

    REXIS, a shoebox-sized student instrument, was designed to measure the X-rays that Bennu emits in response to incoming solar radiation. X-rays are a form of electromagnetic radiation, like visible light, but with much higher energy. REXIS is a collaborative experiment led by students and researchers at MIT and Harvard, who proposed, built, and operate the instrument.

    On Nov. 11, 2019, while the REXIS instrument was performing detailed science observations of Bennu, it captured X-rays radiating from a point off the asteroid’s edge. “Our initial checks showed no previously cataloged object in that position in space,” said Branden Allen, a Harvard research scientist and student supervisor who first spotted the source in the REXIS data.

    The glowing object turned out to be a newly flaring black hole X-ray binary – discovered just a week earlier by Japan’s MAXI telescope – designated MAXI J0637-430. NASA’s Neutron Star Interior Composition Explorer (NICER) telescope also identified the X-ray blast a few days later. Both MAXI and NICER operate aboard NASA’s International Space Station and detected the X-ray event from low Earth orbit. REXIS, on the other hand, detected the same activity millions of miles from Earth while orbiting Bennu, the first such outburst ever detected from interplanetary space.

    “Detecting this X-ray burst is a proud moment for the REXIS team. It means our instrument is performing as expected and to the level required of NASA science instruments,” said Madeline Lambert, an MIT graduate student who designed the instrument’s command sequences that serendipitously revealed the black hole.

    X-ray blasts, like the one emitted from the newly discovered black hole, can only be observed from space since Earth’s protective atmosphere shields our planet from X-rays. These X-ray emissions occur when a black hole pulls in matter from a normal star that is in orbit around it. As the matter spirals onto a spinning disk surrounding the black hole, an enormous amount of energy (primarily in the form of X-rays) is released in the process.

    This image shows the X-ray outburst from the black hole MAXI J0637-043, detected by the REXIS instrument on NASA’s OSIRIS-REx spacecraft. The image was constructed using data collected by the X-ray spectrometer while REXIS was making observations of the space around asteroid Bennu on Nov. 11, 2019. The outburst is visible in the center of the image, and the image is overlaid with the limb of Bennu (lower right) to illustrate REXIS’s field of view. Credit: NASA/Goddard/University of Arizona/MIT/Harvard

    “We set out to train students how to build and operate space instruments,” said MIT professor Richard Binzel, instrument scientist for the REXIS student experiment. “It turns out, the greatest lesson is to always be open to discovering the unexpected.”

    The main purpose of the REXIS instrument is to prepare the next generation of scientists, engineers, and project managers in the development and operations of spaceflight hardware. Nearly 100 undergraduate and graduate students have worked on the REXIS team since the mission’s inception.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and provides flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  13. Status Update: OSIRIS-REx Osprey Flyover

    February 13, 2020 -

    On Feb. 11, NASA’s OSIRIS-REx spacecraft safely executed a 0.4-mile (620-m) flyover of the backup sample collection site Osprey as part of the mission’s Reconnaissance B phase activities. Preliminary telemetry, however, indicates that the OSIRIS-REx Laser Altimeter (OLA) did not operate as expected during the 11-hour event. The OLA instrument was scheduled to provide ranging data to the spacecraft’s PolyCam imager, which would allow the camera to focus while imaging the area around the sample collection site. Consequently, the PolyCam images from the flyover are likely out of focus.

    The other science instruments, including the MapCam imager, the OSIRIS-REx Thermal Emissions Spectrometer (OTES), and the OSIRIS-REx Visual and InfraRed Spectrometer (OVIRS), all performed nominally during the flyover. These instruments and the spacecraft continue in normal operations in orbit around asteroid Bennu.

    The mission team is currently reviewing the available data from the flyover in order to fully assess the OLA instrument. The entire data set from the flyover, including the PolyCam images, will be completely downlinked from the spacecraft next week and will provide additional insight into any impact that the loss of the OLA data may have.

    OLA has already completed all of its principal requirements for the OSIRIS-REx mission. OLA’s scans of Bennu’s surface were used to create the high-resolution 3D global maps of Bennu’s topography that were crucial for selecting the primary and backup sample collection sites last fall.

  14. OSIRIS-REx Completes Closest Flyover of Sample Site Nightingale

    January 22, 2020 -

    Preliminary results indicate that NASA’s OSIRIS-REx spacecraft successfully executed a 0.4-mile (620-m) flyover of site Nightingale yesterday as part of the mission’s Reconnaissance B phase activities. Nightingale, OSIRIS-REx’s primary sample collection site, is located within a crater high in asteroid Bennu’s northern hemisphere.

    During the Recon B flyover of primary sample collection site Nightingale, OSIRIS-REx left its safe-home orbit to fly over the sample site at an altitude of 0.4 miles (620 m). The pass, which took around 11 hours, gave the spacecraft’s onboard instruments the opportunity to take the closest-ever science observations of the site. Credit: NASA/Goddard/University of Arizona

    To perform the pass, the spacecraft left its 0.75-mile (1.2-km) safe home orbit and flew an almost 11-hour transit over the asteroid, aiming its science instruments toward the 52-ft (16-m) wide sample site before returning to orbit. Science observations from this flyover are the closest taken of a sample site to date.

    The primary goal of the Nightingale flyover was to collect the high-resolution imagery required to complete the spacecraft’s Natural Feature Tracking image catalog, which will document the sample collection site’s surface features – such as boulders and craters. During the sampling event, which is scheduled for late August, the spacecraft will use this catalog to navigate with respect to Bennu’s surface features, allowing it to autonomously predict where on the sample site it will make contact . Several of the spacecraft’s other instruments also took observations of the Nightingale site during the flyover event, including the OSIRIS-REx Thermal Emissions Spectrometer (OTES), the OSIRIS-REx Visual and InfraRed Spectrometer (OVIRS), the OSIRIS-REx Laser Altimeter (OLA), and the MapCam color imager.

    A similar flyover of the backup sample collection site, Osprey, is scheduled for Feb. 11. Even lower flybys will be performed later this spring – Mar. 3 for Nightingale and May 26 for Osprey – as part of the mission’s Reconnaissance C phase activities. The spacecraft will perform these two flyovers at an altitude of 820 feet (250 m), which will be the closest it has ever flown over asteroid Bennu’s surface.

  15. X Marks the Spot: NASA Selects Site for Asteroid Sample Collection

    December 12, 2019 -

    After a year scoping out asteroid Bennu’s boulder-scattered surface, the team leading NASA’s first asteroid sample return mission has officially selected a sample collection site.

    This image shows sample site Nightingale, OSIRIS-REx’s primary sample collection site on asteroid Bennu. The image is overlaid with a graphic of the OSIRIS-REx spacecraft to illustrate the scale of the site. Credit: NASA/Goddard/University of Arizona

    The Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-Rex) mission team concluded a site designated “Nightingale” – located in a crater high in Bennu’s northern hemisphere – is the best spot for the OSIRIS-REx spacecraft to snag its sample.

    The OSIRIS-REx team spent the past several months evaluating close-range data from four candidate sites in order to identify the best option for the sample collection. The candidate sites – dubbed Sandpiper, Osprey, Kingfisher, and Nightingale – were chosen for investigation because, of all the potential sampling regions on Bennu, these areas pose the fewest hazards to the spacecraft’s safety while still providing the opportunity for great samples to be gathered.

    “After thoroughly evaluating all four candidate sites, we made our final decision based on which site has the greatest amount of fine-grained material and how easily the spacecraft can access that material while keeping the spacecraft safe,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona in Tucson. “Of the four candidates, site Nightingale best meets these criteria and, ultimately, best ensures mission success.”

    Site Nightingale is located in a northern crater 460 ft (140 m) wide. Nightingale’s regolith – or rocky surface material – is dark, and images show that the crater is relatively smooth. Because it is located so far north, temperatures in the region are lower than elsewhere on the asteroid and the surface material is well-preserved. The crater also is thought to be relatively young, and the regolith is freshly exposed. This means the site would likely allow for a pristine sample of the asteroid, giving the team insight into Bennu’s history.

    Although Nightingale ranks the highest of any location on Bennu, the site still poses challenges for sample collection. The original mission plan envisioned a sample site with a diameter of 164 feet (50 m). While the crater that hosts Nightingale is larger than that, the area safe enough for the spacecraft to touch is much smaller – approximately 52 ft (16 m) in diameter, resulting in a site that is only about one-tenth the size of what was originally envisioned This means the spacecraft has to very accurately target Bennu’s surface. Nightingale also has a building-size boulder situated on the crater’s eastern rim, which could pose a hazard to the spacecraft while backing away after contacting the site.

    This image shows sample site Osprey, OSIRIS-REx’s backup sample collection site on asteroid Bennu. The image is overlaid with a graphic of the OSIRIS-REx spacecraft to illustrate the scale of the site. Credit:

    The mission also selected site Osprey as a backup sample collection site. The spacecraft has the capability to perform multiple sampling attempts, but any significant disturbance to Nightingale’s surface would make it difficult to collect a sample from that area on a later attempt, making a backup site necessary. The spacecraft is designed to autonomously “wave-off” from the site if its predicted position is too close to a hazardous area. During this maneuver, the exhaust plumes from the spacecraft’s thrusters could potentially disturb the surface of the site, due to the asteroid’s microgravity environment. In any situation where a follow-on attempt at Nightingale is not possible, the team will try to collect a sample from site Osprey instead.

    “Bennu has challenged OSIRIS-REx with extraordinarily rugged terrain,” said Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center. “The team has adapted by employing a more accurate, though more complex, optical navigation technique to be able to get into these small areas. We’ll also arm OSIRIS-REx with the capability to recognize if it is on course to touch a hazard within or adjacent to the site and wave-off before that happens.”

    With the selection of final primary and backup sites, the mission team will undertake further reconnaissance flights over Nightingale and Osprey, beginning in January and continuing through the spring. Once these flyovers are complete, the spacecraft will begin rehearsals for its “touch-and-go” sample collection event, which is scheduled for August. The spacecraft will depart Bennu in 2021 and is scheduled to return to Earth in September 2023.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and provides flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

    This flat projection mosaic of asteroid Bennu shows the relative locations of the primary and backup sample collection sites on the asteroid: Nightingale and Osprey. NASA’s OSIRIS-REx spacecraft is scheduled to collect a sample in summer 2020. Credit: NASA/Goddard/University of Arizona

     

  16. NASA’s OSIRIS-REx Mission Explains Bennu’s Mysterious Particle Events

    December 4, 2019 -

    Shortly after NASA’s OSIRIS-REx spacecraft arrived at asteroid Bennu, an unexpected discovery by the mission’s science team revealed that the asteroid could be active, or consistently discharging particles into space. The ongoing examination of Bennu – and its sample that will eventually be returned to Earth – could potentially shed light on why this intriguing phenomenon is occurring.

    This view of asteroid Bennu ejecting particles from its surface on January 6 was created by combining two images taken by the NavCam 1 imager onboard NASA’s OSIRIS-REx spacecraft: a short exposure image (1.4 ms), which shows the asteroid clearly, and a long exposure image (5 sec), which shows the particles clearly. Credit: NASA/Goddard/University of Arizona/Lockheed Martin

    The OSIRIS-REx team first observed a particle ejection event in images captured by the spacecraft’s navigation cameras taken on Jan. 6, just a week after the spacecraft entered its first orbit around Bennu. At first glance, the particles appeared to be stars behind the asteroid, but on closer examination, the team realized that the asteroid was ejecting material from its surface. After concluding that these particles did not compromise the spacecraft’s safety, the mission began dedicated observations in order to fully document the activity.

    “Among Bennu’s many surprises, the particle ejections sparked our curiosity, and we’ve spent the last several months investigating this mystery,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “This is a great opportunity to expand our knowledge of how asteroids behave.”

    After studying the results of the observations, the mission team released their findings in a Science paper published Dec. 6. The team observed the three largest particle ejection events on Jan. 6 and 19, and Feb. 11, and concluded that the events originated from different locations on Bennu’s surface. The first event originated in the southern hemisphere, and the second and third events occurred near the equator. All three events took place in the late afternoon on Bennu.

    The team found that, after ejection from the asteroid’s surface, the particles either briefly orbited Bennu and fell back to its surface or escaped from Bennu into space. The observed particles traveled up to 10 feet (3 meters) per second, and measured from smaller than an inch up to 4 inches (10 cm) in size. Approximately 200 particles were observed during the largest event, which took place on Jan. 6.

    The team investigated a wide variety of possible mechanisms that may have caused the ejection events, and narrowed the list to three candidates: meteoroid impacts, thermal stress fracturing, and released of water vapor.

    Meteoroid impacts are common in the deep space neighborhood of Bennu, and it is possible that these small fragments of space rock could be hitting Bennu where OSIRIS-REx is not observing it, shaking loose particles with the momentum of their impact.

    The team also determined that thermal fracturing is another reasonable explanation. Bennu’s surface temperatures vary drastically over its 4.3-hour rotation period.

    This animation illustrates the modeled trajectories of particles that were ejected from Bennu’s surface on January 19. After ejecting from the asteroid’s surface, the particles either briefly orbited Bennu and fell back to its surface or escaped away from Bennu and into space. Credit: NASA/Goddard/University of Arizona/Lauretta & Hergenrother et al., Science 10.1126

    Although it is extremely cold during the night hours, the asteroid’s surface warms significantly in the mid-afternoon, which is when the three major events occurred. As a result of this temperature change, rocks may begin to crack and break down, and eventually particles could be ejected from the surface. This cycle is known as thermal stress fracturing.

    Water release may also explain the asteroid’s activity. When Bennu’s water-locked clays are heated, the water could begin to release and create pressure. It is possible that as pressure builds in cracks and pores in boulders where absorbed water is released, the surface could become agitated, causing particles to erupt.

    But nature does not always allow for simple explanations. “It could be that more than one of these possible mechanisms are at play,” said Steve Chesley, an author on the paper and Senior Research Scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “For example, thermal fracturing could be chopping the surface material into small pieces, making it far easier for meteoroid impacts to launch pebbles into space.”

    If thermal fracturing, meteoroid impacts, or both, are in fact the causes of these ejection events, then this phenomenon is likely happening on all small asteroids, as they all experience these mechanisms. However, if water release is the cause of these ejection events, then this phenomenon would be specific to asteroids that contain water-bearing minerals, like Bennu.

    Bennu’s activity presents larger opportunities once a sample is collected and returned to Earth for study. Many of the ejected particles are small enough to be collected by the spacecraft’s sampling mechanism, meaning that the returned sample may possibly contain some material that was ejected and returned to Bennu’s surface. Determining that a particular particle had been ejected and returned to Bennu might be a scientific feat similar to finding a needle in a haystack. The material returned to Earth from Bennu, however, will almost certainly increase our understanding of asteroids and the ways they are both different and similar, even as the particle ejection phenomenon continues to be a mystery whose clues we’ll also return home with in the form of data and further material for study.

    Sample collection is scheduled for summer 2020, and the sample will be delivered to Earth in September 2023.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  17. NASA’s OSIRIS-REx in the Midst of Site Selection

    By Brittany Enos

    December 4, 2019 -

    NASA’s OSIRIS-REx mission is just days away from selecting the site where the spacecraft will snag a sample from asteroid Bennu. After a lengthy and challenging process, the team is finally ready to down-select from the four candidate sites to a primary and backup site.

    OSIRIS-REx is NASA’s first asteroid sample return mission, so this decision of a sample collection site is key for asteroid operations and mission success.

    After selecting the four candidate sample sites – Sandpiper, Osprey, Kingfisher, and Nightingale – in July, the mission completed its Reconnaissance A phase. During Recon A, the OSIRIS-REx spacecraft performed a month-long series of four flyovers – one over each potential sample collection site. This mission phase provided the team with high-resolution imagery in order to thoroughly examine the sampleability (fine-grained material), topography, albedo, and color of each site. The data collected from these high-altitude flyovers is central for determining which site is best-suited for sample collection.

    These are images of the four candidate sample collection sites on asteroid Bennu: Nightingale, Kingfisher, Osprey and Sandpiper. One of these four sites will ultimately be the location on which NASA’s OSIRIS-REx spacecraft will touch down to collect a sample. Credit: NASA/Goddard/University of Arizona

    While the mission is one step closer to collecting a sample, Recon A observations have revealed that even the best candidate sites on Bennu pose significant challenges to sample collection, and the choice before the site selection board is not an easy one.

    “Sample site selection really is a comprehensive activity. It requires that we look at many different types of data in many different ways to ensure the selected site is the best choice in terms of spacecraft safety, presence of sampleable material, and science value,” said Heather Enos, OSIRIS-REx deputy principal investigator at the University of Arizona, Tucson, and chair of the sample site selection board. “Our team is incredibly innovative and integrated, which is what makes the selection process work.”

    The most recent images show that while there is fine-grained material (smaller than 2.5 cm in diameter), much of it may not be easily accessible. The mission was originally designed for a beach-like surface, with “ponds” of sandy material, not for Bennu’s rugged terrain. In reality the potential sample sites are not large, clear areas, but rather small spaces surrounded by large boulders, so navigating the spacecraft in and out of the sites will require a bit more fine-tuning than originally planned.

    Starting in Bennu’s southern hemisphere, site Sandpiper was the first flyover of the Recon A mission phase. Sandpiper is one of the “safer” sites because it is located in a relatively flat area, making it easier for the spacecraft to navigate in and out. The most recent images show that fine-grained material is present, but the sandy regolith is trapped between larger rocks, which makes it difficult for the sampling mechanism to operate.

    Site Osprey was the second site observed during Recon A. This site was originally chosen based on its strong spectral signature of carbon-rich material and because of a dark patch in the center of the crater, which was thought to possibly be fine-grained material. However, the latest high-resolution imagery of Osprey suggests that the site is scattered with material that may be too large to ingest for the sampling mechanism.

    Site Kingfisher was selected because it is located in a small crater – meaning that it may be a relatively young feature compared to Bennu’s larger craters (such as the one in which Sandpiper is located). Younger craters generally hold fresher, minimally-altered material. High-resolution imagery captured during the Recon A flyover revealed that while the original crater may be too rocky, a neighboring crater appears to contain fine-grained material.

    Recon A concluded with a flyover of site Nightingale. Images show that the crater holds a good amount of unobstructed fine-grained material. However, while the sampleability of the site ranks high, Nightingale is located far to the north where the lighting conditions create additional challenges for spacecraft navigation. There is also a building-size boulder situated on the crater’s eastern rim, which could be a hazard to the spacecraft when backing away after contacting the site.

    Bennu has also made it a challenge for the mission to identify a site that won’t trigger the spacecraft’s safety mechanisms. During Recon A, the team began cataloguing Bennu’s surface features to create maps for the Natural Feature Tracking (NFT) autonomous navigation system. During the sample collection event, the spacecraft will use NFT to navigate to the asteroid’s surface by comparing the onboard image catalog to the navigation images it will take during descent. In response to Bennu’s extremely rocky surface, the NFT system has been augmented with a new safety feature, which instructs it to wave-off the sampling attempt and back away if it determines the point of contact is near a potentially hazardous surface feature. With Bennu’s building-sized boulders and small target sites, the team realizes that there is a possibility that the spacecraft will wave-off the first time it descends to collect a sample.

    This flat projection mosaic of asteroid Bennu shows the relative locations of the four candidate sample collection sites on the asteroid: Nightingale, Kingfisher, Osprey and Sandpiper. NASA’s OSIRIS-REx spacecraft is scheduled to touch down on one of these four sites to collect a sample in summer 2020. Credit: NASA/Goddard/University of Arizona

    “Bennu’s challenges are an inherent part of this mission, and the OSIRIS-REx team has responded by developing robust measures to overcome them,” said Mike Moreau, OSIRIS-REx deputy project manager at Goddard. “If the spacecraft executes a wave-off while attempting to collect a sample, that simply means that both the team and the spacecraft have done their jobs to ensure the spacecraft can fly another day. The success of the mission is our first priority.”

    Whichever site wins the race, the OSIRIS-REx mission team is ready for whatever new challenges Bennu may bring. Next spring, the team will undertake further reconnaissance flights over the primary and backup sample sites, and will then start spacecraft rehearsals for touchdown. Sample collection is scheduled for summer 2020, and the sample will return to Earth in September 2023.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  18. Flyover of the Candidate Sample Sites

    August 29, 2019 -

    This animated flyover of each of the four candidate sample collection sites on asteroid Bennu, selected by NASA’s OSIRIS-REx asteroid sample return mission, was produced using close-range data from the OSIRIS-REx Laser Altimeter (OLA), an instrument contributed by the Canadian Space Agency. It illustrates the location of each site on Bennu, the topography of each site, and the potential sampling regions that the spacecraft will target, which are 10 meters in diameter.

    The laser altimeter on NASA’s OSIRIS-REx spacecraft has produced the highest resolution topographic maps ever of any planetary body. These maps of asteroid Bennu provide three-dimensional, detailed views of the OSIRIS-REx mission’s final four candidate sample collection sites, which are designated Nightingale, Kingfisher, Osprey and Sandpiper.

    OLAis equipped with two lasers and uses a steerable mirror to rapidly scan the asteroid’s surface to produce detailed images of boulders, craters and other geological features. OLA collected scans using its low-energy laser transmitter (LELT) during the spacecraft’s low altitude orbit– approximately 700 meters above Bennu’s surface. The LELT is designed to fire 10,000 light pulses per second at the asteroid, and three-dimensional terrain models of the four sites were produced using these light pulses.

    High-resolution maps of the four potential sample sites will allow the OSIRIS-REx team to assess the safety and accessibility of each region, locate landmarks that will help the spacecraft navigate during sample collection and identify areas of fine-grained material compatible with OSIRIS-REx’s sampling mechanism. These maps will be crucial for selecting the final two sample collection sites in December.

    OLA’s LELT will continue to gather Bennu data in tandem with the other instruments on the OSIRIS-REx spacecraft. The final selection of a primary and backup sample collection site will be announced in December 2019, and sample collection is scheduled for the latter half of 2020.

    Credit: NASA/Goddard/University of Arizona/CSA/York University/MDA

  19. NASA Mission Selects Final Four Site Candidates for Asteroid Sample Return

    August 12, 2019 -

    After months grappling with the rugged reality of asteroid Bennu’s surface, the team leading NASA’s first asteroid sample return mission has selected four potential sites for the Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft to “tag” its cosmic dance partner.

    Since its arrival in December 2018, the OSIRIS-REx spacecraft has mapped the entire asteroid in order to identify the safest and most accessible spots for the spacecraft to collect a sample. These four sites now will be studied in further detail in order to select the final two sites – a primary and backup – in December.

    The final four candidate sample collection sites on asteroid Bennu are designated Nightingale, Kingfisher, Osprey and Sandpiper. The final site will be selected in December 2019. Credit: NASA/Goddard/University of Arizona/CSA/York/MDA

    The team originally had planned to choose the final two sites by this point in the mission. Initial analysis of Earth-based observations suggested the asteroid’s surface likely contains large “ponds” of fine-grain material. The spacecraft’s earliest images, however, revealed Bennu has an especially rocky terrain. Since then, the asteroid’s boulder-filled topography has created a challenge for the team to identify safe areas containing sampleable material, which must be fine enough – less than 1 inch (2.5 cm) in diameter – for the spacecraft’s sampling mechanism to ingest it.

    “We knew that Bennu would surprise us, so we came prepared for whatever we might find,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “As with any mission of exploration, dealing with the unknown requires flexibility, resources and ingenuity. The OSIRIS-REx team has demonstrated these essential traits for overcoming the unexpected throughout the Bennu encounter.”

    The original mission schedule intentionally included more than 300 days of extra time during asteroid operations to address such unexpected challenges. In a demonstration of its flexibility and ingenuity in response to Bennu’s surprises, the mission team is adapting its site selection process. Instead of down-selecting to the final two sites this summer, the mission will spend an additional four months studying the four candidate sites in detail, with a particular focus on identifying regions of fine-grain, sampleable material from upcoming, high-resolution observations of each site. The boulder maps that citizen science counters helped create through observations earlier this year were used as one of many pieces of data considered when assessing each site’s safety. The data collected will be key to selecting the final two sites best suited for sample collection.

    In order to further adapt to Bennu’s ruggedness, the OSIRIS-REx team has made other adjustments to its sample site identification process. The original mission plan envisioned a sample site with a radius of 82 feet (25 m). Boulder-free sites of that size don’t exist on Bennu, so the team has instead identified sites ranging from 16 to 33 feet (5 to 10 m) in radius. In order for the spacecraft to accurately target a smaller site, the team reassessed the spacecraft’s operational capabilities to maximize its performance. The mission also has tightened its navigation requirements to guide the spacecraft to the asteroid’s surface, and developed a new sampling technique called “Bullseye TAG,” which uses images of the asteroid surface to navigate the spacecraft all the way to the actual surface with high accuracy. The mission’s performance so far has demonstrated the new standards are within its capabilities.

    “Although OSIRIS-REx was designed to collect a sample from an asteroid with a beach-like area, the extraordinary in-flight performance to date demonstrates that we will be able to meet the challenge that the rugged surface of Bennu presents,” said Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “That extraordinary performance encompasses not only the spacecraft and instruments, but also the team who continues to meet every challenge that Bennu throws at us.”

    The four candidate sample sites on Bennu are designated Nightingale, Kingfisher, Osprey, and Sandpiper – all birds native to Egypt. The naming theme complements the mission’s two other naming conventions – Egyptian deities (the asteroid and spacecraft) and mythological birds (surface features on Bennu).

    The final four candidate sample collection sites on asteroid Bennu are designated Nightingale, Kingfisher, Osprey and Sandpiper. Each circle has a 16.4 ft (5 m) radius. Credit: NASA/Goddard/University of Arizona

    The four sites are diverse in both geographic location and geological features. While the amount of sampleable material in each site has yet to be determined, all four sites have been evaluated thoroughly to ensure the spacecraft’s safety as it descends to, touches and collects a sample from the asteroid’s surface.

    Nightingale is the northern-most site, situated at 56 degrees north latitude on Bennu. There are multiple possible sampling regions in this site, which is set in a small crater encompassed by a larger crater 459 feet (140 m) in diameter. The site contains mostly fine-grain, dark material and has the lowest albedo, or reflection, and surface temperature of the four sites.

    Kingfisher is located in a small crater near Bennu’s equator at 11 degrees north latitude. The crater has a diameter of 26 feet (8 m) and is surrounded by boulders, although the site itself is free of large rocks. Among the four sites, Kingfisher has the strongest spectral signature for hydrated minerals.

    Osprey is set in a small crater, 66 feet (20 m) in diameter, which is also located in Bennu’s equatorial region at 11 degrees north latitude. There are several possible sampling regions within the site. The diversity of rock types in the surrounding area suggests that the regolith within Osprey may also be diverse. Osprey has the strongest spectral signature of carbon-rich material among the four sites.

    Sandpiper is located in Bennu’s southern hemisphere, at 47 degrees south latitude. The site is in a relatively flat area on the wall of a large crater 207 ft (63 m) in diameter. Hydrated minerals are also present, which indicates that Sandpiper may contain unmodified water-rich material.

    This fall, OSIRIS-REx will begin detailed analyses of the four candidate sites during the mission’s reconnaissance phase. During the first stage of this phase, the spacecraft will execute high passes over each of the four sites from a distance of 0.8 miles (1.29 km) to confirm they are safe and contain sampleable material. Closeup imaging also will map the features and landmarks required for the spacecraft’s autonomous navigation to the asteroid’s surface. The team will use the data from these passes to select the final primary and backup sample collection sites in December.

    The final four candidate sample collection sites shown on a map of asteroid Bennu. They are designated Nightingale, Kingfisher, Osprey and Sandpiper. Credit: NASA/Goddard/University of Arizona

    The second and third stages of reconnaissance will begin in early 2020 when the spacecraft will perform passes over the final two sites at lower altitudes and take even higher resolution observations of the surface to identify features, such as groupings of rocks that will be used to navigate to the surface for sample collection. OSIRIS-REx sample collection is scheduled for the latter half of 2020, and the spacecraft will return the asteroid samples to Earth on Sept. 24, 2023.

    Goddard provides overall mission management, systems engineering, and safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

    To explore the final four candidate sites in detail, click here.

  20. Asteroid Bennu’s Features To Be Named After Mythical Birds

    August 8, 2019 -

    Working with NASA’s OSIRIS-REx team, the International Astronomical Union’s Working Group for Planetary System Nomenclature (WGPSN) approved the theme “birds and bird-like creatures in mythology” for naming surface features on asteroid (101955) Bennu.

    This image shows boulder formations on asteroid Bennu’s surface. It was taken by the PolyCam camera on NASA’s OSIRIS-REx spacecraft on April 11, 2019 from a distance of 2.8 miles (4.5 km). Credit: NASA/Goddard/University of Arizona

    OSIRIS-REx is NASA’s first mission to bring a sample from an asteroid back to Earth. The OSIRIS-REx spacecraft has been mapping Bennu’s surface since its arrival on December 3rd, 2018, looking for a site from which to take a sample. Bennu is the smallest body in the Solar System to be orbited and surveyed by a spacecraft at close range.

    The named features on Bennu will include several terrain classification types that the IAU also approved for asteroid (162173) Ryugu’s surface features (currently being explored by the Japanese Space Agency’s Hayabusa2 spacecraft). These include craters, dorsa (peaks or ridges), fossae (grooves or trenches) and saxa (rocks and boulders). The last of these types – saxum – is a new feature classification that the IAU introduced earlier this year for small, rocky asteroids like Ryugu and Bennu. These surface features on Bennu will be named after mythological birds and bird-like creatures, complementing the mission’s existing naming theme, which is rooted in Egyptian mythology.

    The name OSIRIS-REx is an acronym for the mission’s major concepts and goals, which stands for Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer. The name also finds inspiration in the Egyptian myth of the god Osiris. In ancient Egyptian mythology, Osiris is associated with the afterlife, the underworld and rebirth. He granted all life, including sprouting vegetation and the fertile flooding of the Nile River. Similarly, the OSIRIS-REx mission seeks to understand the origin and process of life on Earth by studying Bennu’s carbon-rich regolith.

    Bennu was named in 2013 by a 9-year-old boy from North Carolina who won the Name that Asteroid! Competition, a collaboration between the mission, the Planetary Society, and the LINEAR asteroid survey that discovered Bennu. Michael Puzio won the contest by suggesting that the spacecraft’s Touch-and-Go Sample Mechanism (TAGSAM) arm and solar panels resemble the neck and wings in illustrations of Bennu, whom ancient Egyptians usually depicted as a gray heron. Bennu is the ancient Egyptian deity linked with the Sun, creation and rebirth — Puzio also noted that Bennu is the living symbol of Osiris. The myth of Bennu suits the asteroid itself, given that it is a primitive object that dates back to the creation of the Solar System. Themes of origins, rebirth and duality are all part of this asteroid’s story. Birds and bird-like creatures are also symbolic of rebirth, creation and origins in various ancient myths.

    The process of naming of Bennu’s surface and features will begin this summer. The OSIRIS-REx team is scheduled to begin detailed reconnaissance on candidate sample sites this fall. Sample collection is scheduled for summer 2020, and the sample will return to Earth in September 2023.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  21. NASA’s OSIRIS-REx Mission Breaks Another Orbit Record

    June 13, 2019 -

    On June 12, NASA’s OSIRIS-REx spacecraft performed another significant navigation maneuver—breaking its own world record for the closest orbit of a planetary body by a spacecraft.

    On Jun. 12, 2019, NASA’s OSIRIS-REx spacecraft went into orbit around asteroid Bennu for a second time — breaking its own record for the closest orbit of a planetary body by any spacecraft.

    The maneuver began the mission’s new phase, known as Orbital B, and placed the spacecraft in an orbit 680 meters (2,231 feet) above the surface of asteroid Bennu. The previous record—also set by the OSIRIS-REx spacecraft—was approximately 1.3 kilometers (0.8 miles) above the surface.

    Upon arrival at Bennu, the team observed particles ejecting into space from the asteroid’s surface. To better understand why this is occurring, the first two weeks of Orbital B will be devoted to observing these events by taking frequent images of the asteroid’s horizon. For the remaining five weeks, the spacecraft will map the entire asteroid using most of its onboard science instruments: the OSIRIS-REx Laser Altimeter (OLA) will produce a full terrain map; PolyCam will form a high-resolution, global image mosaic; and the OSIRIS-REx Thermal Emission Spectrometer (OTES) and the REgolith X-ray Imaging Spectrometer (REXIS) will produce global maps in the infrared and X-ray bands. All of these measurements are essential for selecting the best sample collection site on Bennu’s surface.

    OSIRIS-REx will remain in Orbital B until the second week of August, when it will transition to the slightly higher Orbital C for additional particle observations. During Orbital C, the spacecraft will be approximately 1.3 kilometers (0.8 miles) above the asteroid’s surface.

    The OSIRIS-REx team will also use data collected from Orbital B phase to assess the safety and sample-ability (the likelihood that a sample can be collected) of each potential sample collection site. The team will then choose four possible sample sites to be thoroughly evaluated this fall during the Reconnaissance phase of the mission. Data from the Reconnaissance phase will be used to evaluate the candidate sites for further down-selection, as well as provide the closeup imaging required to map the features and landmarks necessary for the spacecraft’s autonomous navigation to the asteroid’s surface.

    On June 12, 2019, NASA’s OSIRIS-REx spacecraft entered its second orbital phase around asteroid Bennu, called Orbital B, and broke its own world record for the closest orbit of a planetary body. The spacecraft moved into a circular orbit 0.4 miles (680 meters) above Bennu’s surface. The previous record was set by OSIRIS-REx on Dec. 31, 2018, when the spacecraft flew 0.8 miles (1.33 km) above the asteroid’s surface during Orbital A phase.

    Several safety requirements must be considered before sample collection. For instance, any candidate site must be clear enough of large rocks or boulders so that the spacecraft can navigate to the surface without encountering dangerous terrain. Additionally, to keep OSIRIS-REx upright during sample collection, the chosen site can’t be tilted too much compared to the sampling arm. Bennu’s unexpectedly rocky surface has made it more challenging than originally predicted to identify sites that meet both of these safety requirements. In response, the team is evaluating both spacecraft and navigation performance capabilities, which will likely enable greater precision guidance to target more confined sites.

    The OSIRIS-REx spacecraft is on a seven-year journey to study the asteroid Bennu and return a sample from its surface to Earth. This sample of a primitive asteroid will help scientists understand the formation of the Solar System over 4.5 billion years ago. Sample collection is scheduled for summer of 2020, and the spacecraft will deliver the sample to Earth in September 2023.

    NASA Goddard provides overall mission management, systems engineering, and safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  22. NASA Invites Public to Help Asteroid Mission Choose Sample Site

    May 22, 2019 -

    Citizen scientists assemble! NASA’s OSIRIS-REx mission to the asteroid Bennu needs extra pairs of eyes to help choose its sample collection site on the asteroid – and to look for anything else that might be scientifically interesting.

    This image shows the wide variety of boulder shapes, sizes and compositions found on asteroid Bennu. It was taken by the PolyCam camera on NASA’s OSIRIS-REx spacecraft on March 28 from a distance of 2.1 miles (3.4 km). Credit: NASA/Goddard/University of Arizona

    The OSIRIS-REx spacecraft has been at Bennu since Dec. 3, 2018, mapping the asteroid in detail, while the mission team searches for a sample collection site that is safe, conducive to sample collection and worthy of closer study. One of the biggest challenges of this effort, which the team discovered after arriving at the asteroid five months ago, is that Bennu has an extremely rocky surface and each boulder presents a danger to the spacecraft’s safety. To expedite the sample selection process, the team is asking citizen scientist volunteers to develop a hazard map by counting boulders.

    “For the safety of the spacecraft, the mission team needs a comprehensive catalog of all the boulders near the potential sample collection sites, and I invite members of the public to assist the OSIRIS-REx mission team in accomplishing this essential task,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson.

    For this effort, NASA is partnering with CosmoQuest, a project run out of the Planetary Science Institute that supports citizen science initiatives. Volunteers will perform the same tasks that planetary scientists do – measuring Bennu’s boulders and mapping its rocks and craters – through the use of a simple web interface. They will also mark other scientifically interesting features on the asteroid for further investigation.

    The boulder mapping work involves a high degree of precision, but it is not difficult. The CosmoQuest mapping app requires a computer with a larger screen and a mouse or trackpad capable of making precise marks. To help volunteers get started, the CosmoQuest team provides an interactive tutorial, as well as additional user assistance through a Discord community and livestreaming sessions on Twitch.

    “We are very pleased and excited to make OSIRIS-REx images available for this important citizen science endeavor,” said Rich Burns, OSIRIS-REx project manager at NASA Goddard Space Flight Center. “Bennu has surprised us with an abundance of boulders. We ask for citizen scientists’ help to evaluate this rugged terrain so that we can keep our spacecraft safe during sample collection operations.”

    This image shows a view of asteroid Bennu’s surface in a region near the equator. It was taken by the PolyCam camera on NASA’s OSIRIS-REx spacecraft on March 21 from a distance of 2.2 miles (3.5 km). Credit: NASA/Goddard/University of Arizona

    Sample return isn’t new for NASA – this year, the agency is celebrating the 50th anniversary of the Apollo missions to the Moon, which allowed astronauts to bring back 842 pounds (382 kilograms) of rocks and lunar soil. Those samples helped scientists discover that the Moon has water locked in its rocks and even permanently frozen in craters. These findings and others inspired the agency to create the Artemis program to return humans to the Moon by 2024 and start preparing for human exploration on Mars.

    “The OSIRIS-REx mission will continue the Apollo legacy by giving scientists precious samples of an asteroid,” said Lori Glaze, director of the Planetary Science Division at NASA Headquarters in Washington. “These samples will help scientists discover the secrets of planetary formation and the origins of our planet Earth.”

    The Bennu mapping campaign continues through July 10, when the mission begins the sample site selection process. Once primary and secondary sites are selected, the spacecraft will begin closer reconnaissance to map the two sites to sub-centimeter resolution. The mission’s Touch-and-Go (TAG) sampling maneuver is scheduled for July 2020, and the spacecraft will return to Earth with its cargo in September 2023.

    Goddard provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

    To volunteer as a Bennu mapper, visit:

    Bennu.cosmoquest.org

  23. OSIRIS-REx Special Collection in Nature

    March 26, 2019 -

    When NASA’s OSIRIS-REx spacecraft arrived at asteroid Bennu on Dec. 3, 2018, it found a tiny world that in many respects was as the mission team had expected based on ground-based observations — but the team also found that Bennu held quite a few surprises, too. On March 19, 2019, Nature­ published a special collection of eight papers from the OSIRIS-REx mission team providing a first look at asteroid Bennu. The following provides the key findings published in those scientific papers. The full Nature collection may be accessed directly here.

    Global elevation map of asteroid Bennu. Credit: NASA/Goddard/University of Arizona

    Lauretta and DellaGiustina et al.The unexpected surface of asteroid (101955) Bennu.Nature.

    NASA’s OSIRIS-REx spacecraft recently arrived at Bennu, a primitive body that represents the objects that may have brought prebiotic molecules and volatiles such as water to Earth. Bennu is a low-albedo B-type asteroid that has been linked to organic-rich hydrated carbonaceous chondrites. Such meteorites are altered by ejection from their parent body and contaminated by atmospheric entry and terrestrial microbes. Therefore, the primary mission objective is to return a sample of Bennu to Earth that is pristine—that is, not affected by these processes. The OSIRIS-REx spacecraft carries a sophisticated suite of instruments to characterize Bennu’s global properties, support the selection of a sampling site and document that site at a sub-centimeter scale. Here we consider early OSIRIS-REx observations of Bennu to understand how the asteroid’s properties compare to pre-encounter expectations and to assess the prospects for sample return. The bulk composition of Bennu appears to be hydrated and volatile-rich, as expected. However, in contrast to pre-encounter modelling of Bennu’s thermal inertia and radar polarization ratios—which indicated a generally smooth surface covered by centimeter-scale particles—resolved imaging reveals an unexpected surficial diversity. The albedo, texture, particle size and roughness are beyond the spacecraft design specifications. On the basis of our pre-encounter knowledge, we developed a sampling strategy to target 50-meter-diameter patches of loose regolith with grain sizes smaller than two centimeters. We observe only a small number of apparently hazard-free regions, of the order of 5 to 20 meters in extent, the sampling of which poses a substantial challenge to mission success.

     

    Barnouin et al.Shape of (101955) Bennu indicative of a rubble pile with internal stiffness.Nature Geoscience.

    The shapes of asteroids reflect interplay between their interior properties and the processes responsible for their formation and evolution as they journey through the Solar System. Prior to the OSIRIS-REx mission, Earth-based radar imaging gave an overview of Bennu’s shape. Here we construct a high-resolution shape model from OSIRIS-REx images. We find that Bennu’s top-like shape, considerable macroporosity and prominent surface boulders suggest that it is a rubble pile. High-standing, north–south ridges that extend from pole to pole, many long grooves and surface mass wasting indicate some low levels of internal friction and/or cohesion. Our shape model indicates that, similar to other top-shaped asteroids, Bennu formed by reaccumulation and underwent past periods of fast spin, which led to its current shape. Today, Bennu might follow a different evolutionary pathway, with an interior stiffness that permits surface cracking and mass wasting.

     

    DellaGiustina and Emery et al.Properties of rubble-pile asteroid (101955) Bennu from OSIRIS-REx imaging and thermal analysis.Nature Astronomy.

    Establishing the abundance and physical properties of regolith and boulders on asteroids is crucial for understanding the formation and degradation mechanisms at work on their surfaces. Using images and thermal data from NASA’s OSIRIS-REx spacecraft, we show that asteroid Bennu’s surface is globally rough, dense with boulders, and low in albedo. The number of boulders is surprising given Bennu’s moderate thermal inertia, suggesting that simple models linking thermal inertia to particle size do not adequately capture the complexity relating these properties. At the same time, we find evidence for a wide range of particle sizes with distinct albedo characteristics. Our findings imply that ages of Bennu’s surface particles span from the disruption of the asteroid’s parent body (boulders) to recent in situ production (micrometer-scale particles).

     

    Hamilton et al.Evidence for widespread hydrated minerals on asteroid (101955) Bennu.Nature Astronomy.

    Early spectral data from the OSIRIS-REx mission reveal evidence for abundant hydrated minerals on the surface of near-Earth asteroid Bennu in the form of a near-infrared absorption near 2.7 µm and thermal infrared spectral features that are most similar to those of aqueously altered CM-type carbonaceous chondrites. We observe these spectral features across the surface of Bennu, and there is no evidence of substantial rotational variability at the spatial scales of tens to hundreds of metres observed to date. In the visible and near-infrared (0.4 to 2.4 µm) Bennu’s spectrum appears featureless and with a blue (negative) slope, confirming previous ground-based observations. Bennu may represent a class of objects that could have brought volatiles and organic chemistry to Earth.

     

    Hergenrother et al.Operational environment and rotational acceleration of asteroid (101955) Bennu from OSIRIS-REx observations.Nature Communications [open access].

    During its approach to asteroid Bennu, NASA’s OSIRIS-REx spacecraft surveyed Bennu’s immediate environment, photometric properties, and rotation state. Discovery of a dusty environment, a natural satellite, or unexpected asteroid characteristics would have had consequences for the mission’s safety and observation strategy. Here we show that spacecraft observations during this period were highly sensitive to satellites (sub-meter scale) but reveal none, although later navigational images indicate that further investigation is needed. We constrain average dust production in September 2018 from Bennu’s surface to an upper limit of 150 g s–1 averaged over 34 min. Bennu’s disk-integrated photometric phase function validates measurements from the pre-encounter astronomical campaign. We demonstrate that Bennu’s rotation rate is accelerating continuously at 3.63 ± 0.52 × 10–6 degrees day–2, likely due to the Yarkovsky–O’Keefe–Radzievskii–Paddack (YORP) effect, with evolutionary implications.

     

    Scheeres et al.The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements.Nature Astronomy.

    The top-shaped morphology characteristic of asteroid Bennu, often found among fast-spinning asteroids and binary asteroid primaries, may have contributed substantially to binary asteroid formation. Yet a detailed geophysical analysis of this morphology for a fast-spinning asteroid has not been possible prior to the OSIRIS-REx mission. Combining the measured Bennu mass and shape obtained during the Preliminary Survey phase of the OSIRIS-REx mission, we find a notable transition in Bennu’s surface slopes within its rotational Roche lobe, defined as the region where material is energetically trapped to the surface. As the intersection of the rotational Roche lobe with Bennu’s surface has been most recently migrating towards its equator (given Bennu’s increasing spin rate), we infer that Bennu’s surface slopes have been changing across its surface within the last million years. We also find evidence for substantial density heterogeneity within this body, suggesting that its interior is a mixture of voids and boulders. The presence of such heterogeneity and Bennu’s top shape are consistent with spin-induced failure at some point in its past, although the manner of its failure cannot yet be determined. Future measurements by the OSIRIS-REx spacecraft will provide insight into and may resolve questions regarding the formation and evolution of Bennu’s top-shape morphology and its link to the formation of binary asteroids.

     

    Walsh et al. Craters, boulders and regolith of (101955) Bennu indicative of an old and dynamic surface.Nature Geoscience.

    Small, kilometer-sized near-Earth asteroids are expected to have young and frequently refreshed surfaces for two reasons: collisional disruptions are frequent in the main asteroid belt where they originate, and thermal or tidal processes act on them once they become near-Earth asteroids. Here we present early measurements of numerous large candidate impact craters on near-Earth asteroid Bennu by the OSIRIS-REx mission, which indicate a surface that is between 100 million and 1 billion years old, predating Bennu’s expected duration as a near-Earth asteroid. We also observe many fractured boulders, the morphology of which suggests an influence of impact or thermal processes over a considerable amount of time since the boulders were exposed at the surface. However, the surface also shows signs of more recent mass movement: clusters of boulders at topographic lows, a deficiency of small craters and infill of large craters. The oldest features likely record events from Bennu’s time in the main asteroid belt.

     

     Enos and Lauretta. A rendezvous with asteroid Bennu.Nature Astronomy.

    The OSIRIS-REx mission has reached its target, asteroid Bennu, and is engaging in reconnaissance and early science observations in preparation for sample collection. Principal investigator team Heather Enos and Dante Lauretta provide an overview.

  24. NASA Mission Reveals Asteroid Has Big Surprises

    March 19, 2019 -

    A NASA spacecraft that will return a sample of a near-Earth asteroid named Bennu to Earth in 2023 made the first-ever close-up observations of particle plumes erupting from an asteroid’s surface. Bennu also revealed itself to be more rugged than expected, challenging the mission team to alter its flight and sample collection plans, due to the rough terrain.

    This view of asteroid Bennu ejecting particles from its surface on January 19 was created by combining two images taken by the NavCam 1 imager onboard NASA’s OSIRIS-REx spacecraft: a short exposure image (1.4 ms), which shows the asteroid clearly, and a long exposure image (5 sec), which shows the particles clearly. Other image processing techniques were also applied, such as cropping and adjusting the brightness and contrast of each layer. Credit: NASA/Goddard/University of Arizona/Lockheed Martin

    Bennu is the target of NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) mission, which began orbiting the asteroid on Dec. 31. Bennu, which is only slightly wider than the height of the Empire State Building, may contain unaltered material from the very beginning of our solar system.

    “The discovery of plumes is one of the biggest surprises of my scientific career,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “And the rugged terrain went against all of our predictions. Bennu is already surprising us, and our exciting journey there is just getting started.”

    Shortly after the discovery of the particle plumes on Jan. 6, the mission science team increased the frequency of observations, and subsequently detected additional particle plumes — also known as “ejection events” — during the following two months. Although many of the particles were ejected clear of Bennu, the team tracked some particles that orbited Bennu as satellites before returning to the asteroid’s surface.

    The OSIRIS-REx team initially spotted the particle ejection events in images while the spacecraft was orbiting Bennu at a distance of about one mile (1.61 kilometers). Following a safety assessment, the mission team concluded the particles did not pose a risk to the spacecraft. The team continues to analyze the particle ejection eventsand their possible causes.

    “The first three months of OSIRIS-REx’s up-close investigation of Bennu have reminded us what discovery is all about — surprises, quick thinking, and flexibility,” said Lori Glaze, acting director of the Planetary Science Division at NASA Headquarters in Washington. “We study asteroids like Bennu to learn about the origin of the solar system. OSIRIS-REx’s sample will help us answer some of the biggest questions about where we come from.”

    OSIRIS-REx launched in 2016 to explore Bennu, which is the smallest body ever orbited by spacecraft. Studying Bennu will allow researchers to learn more about the origins of our solar system, the sources of water and organic molecules on Earth, the resources in near-Earth space, as well as improve our understanding of asteroids that could impact Earth.

    This image shows a view across asteroid Bennu’s southern hemisphere and into space, and it demonstrates the number and distribution of boulders across Bennu’s surface. The image was obtained on Mar. 7 by the PolyCam camera on NASA’s OSIRIS-REx spacecraft from a distance of about 3 miles (5 km). The large, light-colored boulder just below the center of the image is about 24 feet (7.4 meters) wide, which is roughly half the width of a basketball court. Credit: NASA/Goddard/University of Arizona

    The OSIRIS-REx team also didn’t anticipate the number and size of boulders on Bennu’s surface. From Earth-based observations, the team expected a generally smooth surface with a few large boulders. Instead, it discovered Bennu’s entire surface is rough and dense with boulders.

    The higher-than-expected density of boulders means that the mission’s plans for sample collection, also known as Touch-and-Go (TAG), need to be adjusted. The original mission design was based on a sample site that is hazard-free, with an 82-foot (25-meter) radius. However, because of the unexpectedly rugged terrain, the team hasn’t been able to identify a site of that size on Bennu. Instead, it has begun to identify candidate sites that are much smaller in radius.

    The smaller sample site footprint and the greater number of boulders will demand more accurate performance from the spacecraft during its descent to the surface than originally planned. The mission team is developing an updated approach, called Bullseye TAG, to accurately target smaller sample sites.

    “Throughout OSIRIS-REx’s operations near Bennu, our spacecraft and operations team have demonstrated that we can achieve system performance that beats design requirements,” said Rich Burns, the project manager of OSIRIS-REx at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Bennu has issued us a challenge to deal with its rugged terrain, and we are confident that OSIRIS-REx is up to the task.”

    The original, low-boulder estimate was derived both from Earth-based observations of Bennu’s thermal inertia — or its ability to conduct and store heat — and from radar measurements of its surface roughness. Now that OSIRIS-REx has revealed Bennu’s surface up close, those expectations of a smoother surface have been proven wrong. This suggests the computer models used to interpret previous data do not adequately predict the nature of small, rocky, asteroid surfaces. The team is revising these models with the data from Bennu.

    The OSIRIS-REx science team has made many other discoveries about Bennu in the three months since the spacecraft arrived at the asteroid, some of which were presented Tuesday at the 50th Lunar and Planetary Conference in Houston and in a special collection of papers issued by the journal Nature.

    The team has directly observed a change in the spin rate of Bennu as a result of what is known as the Yarkovsky-O’Keefe-Radzievskii-Paddack (YORP) effect. The uneven heating and cooling of Bennu as it rotates in sunlight is causing the asteroid to increase its rotation speed. As a result, Bennu’s rotation period is decreasing by about one second every 100 years. Separately, two of the spacecraft’s instruments, the MapCam color imager and the OSIRIS-REx Thermal Emission Spectrometer (OTES), have made detections of magnetite on Bennu’s surface, which bolsters earlier findings indicating the interaction of rock with liquid water on Bennu’s parent body.

    Goddard provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

  25. NASA’s OSIRIS-REx Spacecraft Enters Orbit Around Bennu, Breaking Record

    By Lonnie Shekhtman

    January 2, 2019 -

    On Dec. 31, 2018, NASA’s OSIRIS-REx spacecraft went into orbit around asteroid Bennu for the first time – — setting new records for the smallest body ever orbited by a spacecraft and the closest orbit of a planetary body by any spacecraft.

    At 2:43 p.m. EST on December 31, while many on Earth prepared to welcome the New Year, NASA’s OSIRIS-REx spacecraft, 70 million miles (110 million kilometers) away, carried out a single, eight-second burn of its thrusters – and broke a space exploration record. The spacecraft entered into orbit around the asteroid Bennu, and made Bennu the smallest object ever to be orbited by a spacecraft.

    “The team continued our long string of successes by executing the orbit-insertion maneuver perfectly,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “With the navigation campaign coming to an end, we are looking forward to the scientific mapping and sample site selection phase of the mission.”

    Lauretta, along with his team, spent the last day of 2018 with his feet planted on Earth, but his mind focused on space. “Entering orbit around Bennu is an amazing accomplishment that our team has been planning for years,” Lauretta said.

    Inching around the asteroid at a snail’s pace, OSIRIS-REx’s first orbit marks a leap for humankind. Never before has a spacecraft from Earth circled so close to such a small space object – one with barely enough gravity to keep a vehicle in a stable orbit.

    Now, the spacecraft will circle Bennu about a mile (1.75 kilometers) from its center, closer than any other spacecraft has come to its celestial object of study. (Previously the closest orbit of a planetary body was in May 2016, when the Rosetta spacecraft orbited about four miles (seven kilometers) from the center of the comet 67P/Churyumov-Gerasimenko.) The comfortable distance is necessary to keep the spacecraft locked to Bennu, which has a gravity force only 5-millionths as strong as Earth’s. The spacecraft is scheduled to orbit Bennu through mid-February at a leisurely 62 hours per orbit.

    Now that the OSIRIS-REx spacecraft is closer to Bennu, physical details about the asteroid will leap into sharper focus, and the spacecraft’s tour of this rubble pile of primordial debris will become increasingly detailed and focused.

    “Our orbit design is highly dependent on Bennu’s physical properties, such as its mass and gravity field, which we didn’t know before we arrived,” said OSIRIS-REx’s flight dynamics system manager Mike Moreau, who is based at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

    “Up until now, we had to account for a wide variety of possible scenarios in our computer simulations to make sure we could safely navigate the spacecraft so close to Bennu. As the team learned more about the asteroid, we incorporated new information to hone in on the final orbit design,” he said.

    The simulations have played a critical role. The OSIRIS-REx mission, after all, was designed based on complex computer programs that predicted — quite accurately, as it turns out — the properties of Bennu and how the spacecraft’s trajectory would behave. This diligent preparation allowed the team to navigate the vehicle safely to Bennu in December and put some questions to rest (there are, indeed, signs of ancient water preserved in Bennu’s rocks) and to fly over its poles and equator in a preliminary survey that led to some surprises (Bennu has many large boulders).

    Having completed the preliminary survey of Bennu with a flyby of its south pole on December 16, the spacecraft moved to a safe 31 miles (50 kilometers) away from the asteroid to give the navigation team a chance to regroup and prepare for orbit insertion. Next, Lockheed Martin engineers programmed the spacecraft to begin moving back to a position about nine miles (15 kilometers) over Bennu’s north pole to prepare for three burns of its thrusters over the course of 10 days that would place the spacecraft into orbit.

    Even though OSIRIS-REx is in the most stable orbit possible, Bennu’s gravitational pull is so tenuous that keeping the spacecraft safe will require occasional adjustments, said Dan Wibben, OSIRIS-REx maneuver and trajectory design lead at KinetX Aerospace in Simi Valley, California.

    “The gravity of Bennu is so small, forces like solar radiation and thermal pressure from Bennu’s surface become much more relevant and can push the spacecraft around in its orbit much more than if it were orbiting around Earth or Mars, where gravity is by far the most dominant force,” he said.

    The OSIRIS-REx navigation team will use “trim” maneuvers to slightly thrust the spacecraft in one direction or another to correct its orbit and counter these small forces. If the spacecraft drifts away from Bennu, or some other problem forces it into safe mode, it has been programmed to fly away from the asteroid to stay safe from impact.

    “It’s simple logic: always burn toward the Sun if something goes wrong,” said Coralie Adam, OSIRIS-REx lead optical navigation engineer at KinetX. Engineers can navigate the spacecraft back into orbit if it drifts away, Adam said, though that’s unlikely to happen.

    The navigation and spacecraft operations teams are focused on the first orbital phase. Their primary goal is to transition away from star-based navigation, which allowed the team to locate the spacecraft based on pictures of the star formations around it taken by the cameras onboard. Navigators use methods like this since there is no GPS in deep space and we can’t see the spacecraft from Earth-based telescopes. From this point forward, though, the OSIRIS-REx team will rely on landmarks on Bennu’s surface to track OSIRIS-REx, a more precise technique that will ultimately guide them to a sample-collection site clear of boulders and large rocks, said Adam.

    “After conducting a global imaging and mapping campaign during our recent preliminary survey phase, the science team has created 3-D models of Bennu’s terrain that we’re going to begin using for navigation around the asteroid,” she said.

    Another critical objective of this orbital phase, Adam said, is to get a better handle on Bennu’s mass and gravity, features that will influence the planning of the rest of the mission, notably the short touchdown on the surface for sample collection in 2020. In the case of Bennu, scientists can only measure these features by getting OSIRIS-REx very close to the surface to see how its trajectory bends from Bennu’s gravitational pull.

    “The Orbital A phase will help improve our detailed models for Bennu’s gravity field, thermal properties, orientation, and spin rate,” said Wibben. “This, in turn, will allow us to refine our trajectory designs for the even more challenging flight activities we will perform in 2019.”

    The December 31 maneuver to place the spacecraft into orbit about Bennu is the first of many exciting navigation activities planned for the mission. The OSIRIS-REx team will resume science operations in late February. At that point, the spacecraft will perform a series of close flybys of Bennu for several months to take high-resolution images of every square inch of the asteroid to help select a sampling site. During the summer of 2020, the spacecraft will briefly touch the surface of Bennu to retrieve a sample. The OSIRIS-REx mission is scheduled to deliver the sample to Earth in September 2023.

    Goddard provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama for the agency’s Science Mission Directorate in Washington.

  26. NASA’s OSIRIS-REx Spacecraft Enters Close Orbit Around Bennu, Breaking Record

    By Lonnie Shekhtman

    December 31, 2018 -

    On Dec. 31, 2018, NASA’s OSIRIS-REx spacecraft went into orbit around asteroid Bennu for the first time.

    At 2:43 p.m. EST on December 31, while many on Earth prepared to welcome the New Year, NASA’s OSIRIS-REx spacecraft, 70 million miles (110 million kilometers) away, carried out a single, eight-second burn of its thrusters – and broke a space exploration record. The spacecraft entered into orbit around the asteroid Bennu, and made Bennu the smallest object ever to be orbited by a spacecraft.

    “The team continued our long string of successes by executing the orbit-insertion maneuver perfectly,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “With the navigation campaign coming to an end, we are looking forward to the scientific mapping and sample site selection phase of the mission.”

    Lauretta, along with his team, spent the last day of 2018 with his feet planted on Earth, but his mind focused on space. “Entering orbit around Bennu is an amazing accomplishment that our team has been planning for years,” Lauretta said.

    Inching around the asteroid at a snail’s pace, OSIRIS-REx’s first orbit marks a leap for humankind. Never before has a spacecraft from Earth circled so close to such a small space object – one with barely enough gravity to keep a vehicle in a stable orbit.

    Now, the spacecraft will circle Bennu about a mile (1.75 kilometers) from its center, closer than any other spacecraft has come to its celestial object of study. (Previously the closest orbit of a planetary body was in May 2016, when the Rosetta spacecraft orbited about four miles (seven kilometers) from the center of the comet 67P/Churyumov-Gerasimenko.) The comfortable distance is necessary to keep the spacecraft locked to Bennu, which has a gravity force only 5-millionths as strong as Earth’s. The spacecraft is scheduled to orbit Bennu through mid-February at a leisurely 62 hours per orbit.

    Now that the OSIRIS-REx spacecraft is closer to Bennu, physical details about the asteroid will leap into sharper focus, and the spacecraft’s tour of this rubble pile of primordial debris will become increasingly detailed and focused.

    “Our orbit design is highly dependent on Bennu’s physical properties, such as its mass and gravity field, which we didn’t know before we arrived,” said OSIRIS-REx’s flight dynamics system manager Mike Moreau, who is based at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

    “Up until now, we had to account for a wide variety of possible scenarios in our computer simulations to make sure we could safely navigate the spacecraft so close to Bennu. As the team learned more about the asteroid, we incorporated new information to hone in on the final orbit design,” he said.

    The simulations have played a critical role. The OSIRIS-REx mission, after all, was designed based on complex computer programs that predicted — quite accurately, as it turns out — the properties of Bennu and how the spacecraft’s trajectory would behave. This diligent preparation allowed the team to navigate the vehicle safely to Bennu in December and put some questions to rest (there are, indeed, signs of ancient water preserved in Bennu’s rocks) and to fly over its poles and equator in a preliminary survey that led to some surprises (Bennu has many large boulders).

    Having completed the preliminary survey of Bennu with a flyby of its south pole on December 16, the spacecraft moved to a safe 31 miles (50 kilometers) away from the asteroid to give the navigation team a chance to regroup and prepare for orbit insertion. Next, Lockheed Martin engineers programmed the spacecraft to begin moving back to a position about nine miles (15 kilometers) over Bennu’s north pole to prepare for three burns of its thrusters over the course of 10 days that would place the spacecraft into orbit.

    Even though OSIRIS-REx is in the most stable orbit possible, Bennu’s gravitational pull is so tenuous that keeping the spacecraft safe will require occasional adjustments, said Dan Wibben, OSIRIS-REx maneuver and trajectory design lead at KinetX Aerospace in Simi Valley, California.

    “The gravity of Bennu is so small, forces like solar radiation and thermal pressure from Bennu’s surface become much more relevant and can push the spacecraft around in its orbit much more than if it were orbiting around Earth or Mars, where gravity is by far the most dominant force,” he said.

    The OSIRIS-REx navigation team will use “trim” maneuvers to slightly thrust the spacecraft in one direction or another to correct its orbit and counter these small forces. If the spacecraft drifts away from Bennu, or some other problem forces it into safe mode, it has been programmed to fly away from the asteroid to stay safe from impact.

    “It’s simple logic: always burn toward the Sun if something goes wrong,” said Coralie Adam, OSIRIS-REx lead optical navigation engineer at KinetX. Engineers can navigate the spacecraft back into orbit if it drifts away, Adam said, though that’s unlikely to happen.

    The navigation and spacecraft operations teams are focused on the first orbital phase. Their primary goal is to transition away from star-based navigation, which allowed the team to locate the spacecraft based on pictures of the star formations around it taken by the cameras onboard. Navigators use methods like this since there is no GPS in deep space and we can’t see the spacecraft from Earth-based telescopes. From this point forward, though, the OSIRIS-REx team will rely on landmarks on Bennu’s surface to track OSIRIS-REx, a more precise technique that will ultimately guide them to a sample-collection site clear of boulders and large rocks, said Adam.

    “After conducting a global imaging and mapping campaign during our recent preliminary survey phase, the science team has created 3-D models of Bennu’s terrain that we’re going to begin using for navigation around the asteroid,” she said.

    Another critical objective of this orbital phase, Adam said, is to get a better handle on Bennu’s mass and gravity, features that will influence the planning of the rest of the mission, notably the short touchdown on the surface for sample collection in 2020. In the case of Bennu, scientists can only measure these features by getting OSIRIS-REx very close to the surface to see how its trajectory bends from Bennu’s gravitational pull.

    “The Orbital A phase will help improve our detailed models for Bennu’s gravity field, thermal properties, orientation, and spin rate,” said Wibben. “This, in turn, will allow us to refine our trajectory designs for the even more challenging flight activities we will perform in 2019.”

    The December 31 maneuver to place the spacecraft into orbit about Bennu is the first of many exciting navigation activities planned for the mission. The OSIRIS-REx team will resume science operations in late February. At that point, the spacecraft will perform a series of close flybys of Bennu for several months to take high-resolution images of every square inch of the asteroid to help select a sampling site. During the summer of 2020, the spacecraft will briefly touch the surface of Bennu to retrieve a sample. The OSIRIS-REx mission is scheduled to deliver the sample to Earth in September 2023.

    Goddard provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama for the agency’s Science Mission Directorate in Washington.

  27. NASA’s Newly Arrived OSIRIS-REx Spacecraft Already Discovers Water on Asteroid

    December 10, 2018 -

    Recently analyzed data from NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) mission has revealed water locked inside the clays that make up its scientific target, the asteroid Bennu.

    This mosaic image of asteroid Bennu is composed of 12 PolyCam images collected on Dec. 2 by the OSIRIS-REx spacecraft from a range of 15 miles (24 km).
    Credit: NASA/Goddard/University of Arizona

    During the mission’s approach phase, between mid-August and early December, the spacecraft traveled 1.4 million miles (2.2 million km) on its journey from Earth to arrive at a location 12 miles (19 km) from Bennu on Dec. 3. During this time, the science team on Earth aimed three of the spacecraft’s instruments towards Bennu and began making the mission’s first scientific observations of the asteroid. OSIRIS-REx is NASA’s first asteroid sample return mission.

    Data obtained from the spacecraft’s two spectrometers, the OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) and the OSIRIS-REx Thermal Emission Spectrometer (OTES), reveal the presence of molecules that contain oxygen and hydrogen atoms bonded together, known as “hydroxyls.” The team suspects that these hydroxyl groups exist globally across the asteroid in water-bearing clay minerals, meaning that at some point, Bennu’s rocky material interacted with water. While Bennu itself is too small to have ever hosted liquid water, the finding does indicate that liquid water was present at some time on Bennu’s parent body, a much larger asteroid.

    “The presence of hydrated minerals across the asteroid confirms that Bennu, a remnant from early in the formation of the solar system, is an excellent specimen for the OSIRIS-REx mission to study the composition of primitive volatiles and organics,” said Amy Simon, OVIRS deputy instrument scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “When samples of this material are returned by the mission to Earth in 2023, scientists will receive a treasure trove of new information about the history and evolution of our solar system.”

    Additionally, data obtained from the OSIRIS-REx Camera Suite (OCAMS) corroborate ground-based telescopic observations of Bennu and confirm the original model developed in 2013 by OSIRIS-REx Science Team Chief Michael Nolan and collaborators. That model closely predicted the asteroid’s actual shape, with Bennu’s diameter, rotation rate, inclination, and overall shape presented almost exactly as projected.

    This preliminary shape model of asteroid Bennu was created from a compilation of images taken by OSIRIS-REx’s PolyCam camera during the spacecraft’s approach toward Bennu during the month of November. This 3D shape model shows features on Bennu as small as six meters.
    Credit: NASA/Goddard/University of Arizona

    One outlier from the predicted shape model is the size of the large boulder near Bennu’s south pole. The ground-based shape model calculated this boulder to be at least 33 feet (10 meters) in height. Preliminary calculations from OCAMS observations show that the boulder is closer to 164 feet (50 meters) in height, with a width of approximately 180 feet (55 meters).

    Bennu’s surface material is a mix of very rocky, boulder-filled regions and a few relatively smooth regions that lack boulders. However, the quantity of boulders on the surface is higher than expected. The team will make further observations at closer ranges to more accurately assess where a sample can be taken on Bennu to later be returned to Earth.

    “Our initial data show that the team picked the right asteroid as the target of the OSIRIS-REx mission. We have not discovered any insurmountable issues at Bennu so far,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “The spacecraft is healthy and the science instruments are working better than required. It is time now for our adventure to begin.”

    The mission currently is performing a preliminary survey of the asteroid, flying the spacecraft in passes over Bennu’s north pole, equator, and south pole at ranges as close as 4.4 miles (7 km) to better determine the asteroid’s mass. The mission’s scientists and engineers must know the mass of the asteroid in order to design the spacecraft’s insertion into orbit because mass affects the asteroid’s gravitational pull on the spacecraft. Knowing Bennu’s mass will also help the science team understand the asteroid’s structure and composition.

    This survey also provides the first opportunity for the OSIRIS-REx Laser Altimeter (OLA), an instrument contributed by the Canadian Space Agency, to make observations, now that the spacecraft is in proximity to Bennu.

    The spacecraft’s first orbital insertion is scheduled for Dec. 31, and OSIRIS-REx will remain in orbit until mid-February 2019, when it exits to initiate another series of flybys for the next survey phase. During the first orbital phase, the spacecraft will orbit the asteroid at a range of 0.9 miles (1.4 km) to 1.24 miles (2.0 km) from the center of Bennu — setting new records for the smallest body ever orbited by a spacecraft and the closest orbit of a planetary body by any spacecraft.

    Goddard provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space Systems in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for the Science Mission Directorate in Washington.

  28. NASA’S OSIRIS-REx Spacecraft Arrives at Asteroid Bennu

    December 3, 2018 -

    NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft completed its 1.2 billion-mile (2 billion-kilometer) journey to arrive at the asteroid Bennu Monday. The spacecraft executed a maneuver that transitioned it from flying toward Bennu to operating around the asteroid.

    This series of images taken by the OSIRIS-REx spacecraft shows Bennu in one full rotation from a distance of around 50 miles (80 km). The spacecraft’s PolyCam camera obtained the 36 2.2-millisecond frames over a period of four hours and 18 minutes. Credit: NASA/Goddard/University of Arizona

    Now, at about 11.8 miles (19 kilometers) from Bennu’s Sun-facing surface, OSIRIS-REx will begin a preliminary survey of the asteroid. The spacecraft will commence flyovers of Bennu’s north pole, equatorial region, and south pole, getting as close as nearly 4 miles (7 kilometers) above Bennu during each flyover.

    The primary science goals of this survey are to refine estimates of Bennu’s mass and spin rate, and to generate a more precise model of its shape. The data will help determine potential sites for later sample collection.

    OSIRIS-REx’s mission will help scientists investigate how planets formed and how life began, as well as improve our understanding of asteroids that could impact Earth. Asteroids are remnants of the building blocks that formed the planets and enabled life. Those like Bennu contain natural resources, such as water, organics and metals. Future space exploration and economic development may rely on asteroids for these materials.

    “As explorers, we at NASA have never shied away from the most extreme challenges in the solar system in our quest for knowledge,” said Lori Glaze, acting director for NASA’s Planetary Science Division. “Now we’re at it again, working with our partners in the U.S. and Canada to accomplish the Herculean task of bringing back to Earth a piece of the early solar system.”

    The mission’s navigation team will use the preliminary survey of Bennu to practice the delicate task of navigating around the asteroid. The spacecraft will enter orbit around Bennu on Dec. 31 –thus making Bennu, which is only about 1,600 feet (492 meters) across — or about the length of five football fields — the smallest object ever orbited by a spacecraft. It’s a critical step in OSIRIS-REx’s years-long quest to collect and eventually deliver at least two ounces (60 grams) of regolith — dirt and rocks — from Bennu to Earth.

    Starting in October, OSIRIS-REx performed a series of braking maneuvers to slow the spacecraft down as it approached Bennu. These maneuvers also targeted a trajectory to set up Monday’s maneuver, which initiates the first north pole flyover and marks the spacecraft’s arrival at Bennu.

    “The OSIRIS-REx team is proud to cross another major milestone off our list — asteroid arrival,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “Initial data from the approach phase show this object to have exceptional scientific value. We can’t wait to start our exploration of Bennu in earnest. We’ve been preparing for this moment for years, and we’re ready.”

    OSIRIS-REx mission marks many firsts in space exploration. It will be the first U.S. mission to carry samples from an asteroid back to Earth and the largest sample returned from space since the Apollo era. It’s the first to study a primitive B-type asteroid, which is an asteroid that’s rich in carbon and organic molecules that make up life on Earth. It is also the first mission to study a potentially hazardous asteroid and try to determine the factors that alter their courses to bring them close to Earth.

    “During our approach toward Bennu, we have taken observations at much higher resolution than were available from Earth,” said Rich Burns, the project manager of OSIRIS-REx at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “These observations have revealed an asteroid that is both consistent with our expectations from ground-based measurements and an exceptionally interesting small world. Now we embark on gaining experience flying our spacecraft about such a small body.”

    When OSIRIS-REx begins to orbit Bennu at the end of this month, it will come close to approximately three quarters of a mile (1.25 kilometers) to its surface. In February 2019, the spacecraft begins efforts to globally map Bennu to determine the best site for sample collection. After the collection site is selected, the spacecraft will briefly touch the surface of Bennu to retrieve a sample. OSIRIS-REx is scheduled to return the sample to Earth in September 2023.

    Goddard provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama for the agency’s Science Mission Directorate in Washington.

  29. TAGSAM Testing Complete: OSIRIS-REx Prepared to TAG an Asteroid

    By Christine Hoekenga

    November 16, 2018 -

    On Nov. 14, NASA’s OSIRIS-REx spacecraft stretched out its robotic sampling arm for the first time in space. The arm, more formally known as the Touch-and-Go Sample Acquisition Mechanism (TAGSAM), is key to the spacecraft achieving the primary goal of the mission: returning a sample from asteroid Bennu in 2023.

    OSIRIS-REx's TAGSAM Head as Imaged by SamCam

    This image, showing the OSIRIS-REx Touch-and-Go Sample Acquisition Mechanism (TAGSAM) sampling head extended from the spacecraft at the end of the TAGSAM arm, was taken by the SamCam camera on Nov. 14, 2018 during a visual checkout of the spacecraft’s sampling system. A similar observation will be taken after TAG to help document the asteroid material collected in the TAGSAM head. Credit: NASA/Goddard/University of Arizona

    As planned, engineers at Lockheed Martin commanded the spacecraft to move the arm through its full range of motion – flexing its shoulder, elbow, and wrist “joints.” This long-awaited stretch, which was confirmed by telemetry data and imagery captured by the spacecraft’s SamCam camera, demonstrates that the TAGSAM head is ready to collect a sample of loose dirt and rock (called regolith) from Bennu’s surface.

    “The TAGSAM exercise is an important milestone, as the prime objective of the OSIRIS-REx mission is to return a sample of Bennu to Earth,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “This successful test shows that, when the time comes, TAGSAM is ready to reach out and tag the asteroid.”

    Years of innovation

    Lockheed Martin engineers spent more than a decade designing, building, and testing TAGSAM, which includes an 11-foot (3.35-meter) arm with three articulating joints, a round sampler head at the end of the arm that resembles the air filter in a car, and three bottles of high-pressure nitrogen gas.

    This test deployment was a rehearsal for a date in mid-2020 when the spacecraft will unfold the TAGSAM arm again, slowly descend to Bennu’s surface, and briefly touch the asteroid with the sampler head. A burst of nitrogen gas will stir up regolith on the asteroid’s surface, which will be caught in the TAGSAM head. The TAG sequence will take about five seconds, after which the spacecraft will execute small maneuvers to carefully back away from Bennu. Afterward, SamCam will image the sampler head, as it did during the test deployment, to help confirm that TAGSAM collected at least 2.1 ounces (60 grams) of regolith.

    The TAGSAM mechanism was designed for the key challenge unique to the OSIRIS-REx mission: collecting a sample from the smallest planetary body ever to be orbited by a spacecraft. “First-of-its-kind innovations like this one serve as the precursor for future missions to small bodies,” said Sandy Freund, systems engineer manager and Lockheed Martin OSIRIS-REx MSA manager. “By proving out these technologies and techniques, we are going to be able to return the largest sample from space in half a century and pave the way for other missions.”

    A month of testing

    The unfolding of the TAGSAM arm was the latest and most significant step in a series of tests and check-outs of the spacecraft’s sampling system, which began in October when OSIRIS-REx jettisoned the cover that protected the TAGSAM head during launch and the mission’s outbound cruise phase. Shortly before the cover ejection, and again the day after, OSIRIS-REx performed two spins called Sample Mass Measurements. By comparing the spacecraft’s inertial properties during these before-and-after spins, the team confirmed that the 2.67-pound (1.21-kilogram) cover was successfully ejected on Oct. 17.

    A week later, on Oct. 25, the Frangibolts holding the TAGSAM arm in place fired successfully, releasing the arm and allowing the team to move it into a parked position just outside its protective housing. After resting in this position for a few weeks, the arm was fully deployed into its sampling position, its joints were tested, and images were captured with SamCam. The spacecraft will execute two additional Sample Mass Measurements over the next two days. The mission team will use these spins as a baseline to compare with the results of similar spins that will be conducted after TAG in 2020 in order to confirm the mass of the sample collected.

    Although the sampling system was rigorously tested on Earth, this rehearsal marked the first time that the team has deployed TAGSAM in the micro-gravity environment of space.

    “The team is very pleased that TAGSAM has been released, deployed, and is operating as commanded through its full range of motion.” said Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “It has been restrained for over two years since launch, so it is gratifying to see it out of its shackles and performing well.”

    OSIRIS-REx is scheduled to arrive at Bennu on Dec. 3. It will spend nearly one year surveying the asteroid with five scientific instruments so that the mission team can select a location that is safe and scientifically interesting to collect the sample.

    “Now that we have put TAGSAM through its paces in space and know it is ready to perform at Bennu, we can focus on the challenges of navigating around the asteroid and seeking out the best possible sample site,” said Lauretta.

  30. NASA’s OSIRIS-REx Executes Fourth Asteroid Approach Maneuver

    November 13, 2018 -

    Artist’s conception of NASA’s OSIRIS-REx spacecraft during a burn of its Attitude Control System (ACS) thrusters.

    NASA’s OSIRIS-REx spacecraft executed its fourth Asteroid Approach Maneuver (AAM-4) yesterday. The spacecraft fired its Attitude Control System (ACS) thrusters to slow the spacecraft from approximately 0.31 mph (0.14 m/sec) to 0.10 mph (0.04 m/sec). The ACS thrusters are capable of velocity changes as small as 0.02 mph (0.01 m/sec). The mission team will continue to examine telemetry and tracking data over the next week to verify the new trajectory. The maneuver targeted the spacecraft to fly through a corridor designed for the collection of high-resolution images that will be used to build a shape model of Bennu.

    With the execution of AAM-4, the OSIRIS-REx spacecraft concludes a six-week series of Bennu approach maneuvers. AAM-1 and AAM-2, which executed on Oct. 1 and Oct. 15 respectively, slowed the spacecraft by a total of approximately 1,088 mph (486 m/sec). AAM-3 and AAM-3A, which executed on Oct. 29 and Nov. 5 respectively, further refined the spacecraft’s trajectory and speed to set the conditions for a successful AAM-4 maneuver. After a final correction maneuver scheduled for Nov. 30, the spacecraft will be on track to arrive at a position 12 miles (20 km) from Bennu on Dec. 3.

  31. Behind the Scenes of REXIS: Uncovering an Instrument in Flight

    By Rebecca Masterson, REXIS Instrument Program Manager

    November 13, 2018 -

    On Sept. 14, OSIRIS-REx’s REXIS instrument opened its radiation cover, as scheduled, after two years in space. The cover had been in place to protect REXIS’s charge-coupled devices (CCDs) from degradation due to radiation exposure during the spacecraft’s cruise to Bennu. The REXIS student team designed and built the cover with input from MIT and NASA Goddard mentors and members of the OSIRIS-REx review board.

    Figure 1: CAD model of the REXIS cover in the closed position, showing the Frangibolt housing and cover heater. The flight instrument also includes a heater on the Frangibolt housing that is not shown here.

    Since its installation, the radiation cover had been held closed with a titanium bolt that was threaded through a TiNi Aerospace FD04 Frangibolt and a switch washer (see Figure 1). When it was time to release the cover, the team sent REXIS a command to heat the Frangibolt until the shape memory alloy expanded. This put the bolt under tension, causing structural failure, so that the cover was free to swing open. The switch washer sensed the change in pre-load at the joint and sent a signal to the REXIS electronics board to cut power to the Frangibolt, stopping the activity.

    Figure 2: Photo of the REXIS flight instrument (before spacecraft integration) with radiation cover open. This configuration is the most-likely current configuration of the instrument on-board OSIRIS-REx after firing the Frangibolt.

    In the event that the switch washer did not work as expected, the team had also set a software timer to end the actuation activity in order to ensure that the Frangibolt did not overheat. The exact time needed to actuate the Frangibolt was unknown, as it depended heavily on the temperatures of the actuator and the cover as well as the pre-load in the joint. Therefore, the REXIS team tested both the flight instrument and spare covers in advance to try to set this timer correctly. Three attempts to open the instrument were planned, each with a slightly longer timer setting.

    For the first attempt, the team set the REXIS firing timer to 57 seconds. If the switch washer didn’t show actuation in that time, the bolt was programmed to turn off. The firing command was sent to the instrument at about 16:32 UTC. Fifty-five seconds later, the switch washer indicated that the Frangibolt had actuated … with only two seconds to spare. Kudos to the team that tested the spare cover over various temperature ranges in order to guide us to such a perfect timer setting.

    We also saw evidence of the firing in the onboard instrument temperature sensors: the housing temperature and the CCD temperature both decreased after the firing, which indicated that the cover was no longer conductively connected to the instrument tower (see Figure 3).

     

    Figure 3: The REXIS housekeeping temperatures before and after firing also show changes expected with the cover open. Both the CCD temperatures (top plot) and the Frangibolt housing temperature (middle plot, “Frangibolt”) decrease after the firing event indicating that the cover and its heater are no longer thermally coupled to the rest of the instrument.

     

    The duty cycle of the housing heater and the cover heater also changed as expected. The REXIS Frangibolt housing heater stayed on after the cover opening  since the housing is no longer getting heat from the cover heater. The cover heater duty cycle has also lengthened since the thermal mass has decreased (see Figure 4).

     

    Figure 4: REXIS cover heater current values during the cover opening event. Before the cover was open both the housing heater and the cover heater were cycling with a short duty cycle. The changes in the data after the firing attempt indicate that the housing heater is now always on and the cover heater is cycling less frequently. This behavior is expected in the cover open state.

     

    REXIS took 30 minutes of science data before and after the Frangibolt firing so we could compare the spectra. With the cover open, we were expecting to see an increase in the rate of events detected by the CCDs, dominantly in the low energy portion of the x-ray spectrum due to the Cosmic X-ray Background (CXB). The cover included an Fe-55 calibration source that shone on the CCDs and had been used to monitor the instrument status for its two years in flight. Opening the cover removed that source from the field of view of the CCDs, so we also expected to see a decrease in the Fe-55 energy detected. As expected, the rate of events detected by the CCDs increased, as shown in Figure 4. The x-ray spectrum from one of the instrument’s highest performing CCD nodes is shown in Figure 5.

    Figure 5: Rate of X-ray events detected by the CCDs during the cover opening activity. The detected event rate has a discontinuous step in the 30 minutes before and after the cover opened. The increase in the event rate is due to diffuse x-ray emission of the cosmic x-ray background as expected with an open cover.

    The x-ray spectrum measured in the low energy range increased, just as expected for the CXB ,while the calibration source signal from Fe-55 became less pronounced. The data in Figure 5 and Figure 6 are consistent with a fully open REXIS cover.

    Figure 6: The x-ray spectrum is a measure of the number of events detected by the CCDs as a function of energy. The red line is the x-ray spectra detected by one of the highest-performing nodes in the REXIS detector array before the cover opened. There is a peak 5.9 keV (the blue shaded region) from the cover-mounted internal Fe-55 x-ray calibration source. The low energy spectrum is due to only internal noise. The spectrum after the cover opened for the same node (black line) shows detection of a low-energy continuum consistent with predictions of the cosmic x-ray background (blue dashed line) and a weakening of the Fe-55 line indicating that the instrument is now looking at cosmic x-rays from space instead of the underside of the cover.

    Given both this science and engineering data, we are confident that our radiation cover is open and out of the field of view of the REXIS CCDs. Now the REXIS team can start doing real external calibrations. REXIS will be looking at some Cosmic X-Ray Background (CXB) in early October and then will turn to check out the Crab Nebula in November.

  32. NASA’s OSIRIS-REx Executes Third Asteroid Approach Maneuver

    October 29, 2018 -

    Artist’s conception of NASA’s OSIRIS-REx spacecraft during a burn of its trajectory correction maneuver (TCM) engines.

    NASA’s OSIRIS-REx spacecraft executed its third Asteroid Approach Maneuver (AAM-3) today. The trajectory correction maneuver (TCM) thrusters fired in a series of two braking maneuvers designed to slow the spacecraft’s speed relative to Bennu from approximately 11.7 mph (5.2 m/sec) to .24 mph (.11 m/sec). Due to constraints that science instruments not be pointed too closely to the Sun, this maneuver was designed as two separate burns of approximately 5.8 mph (2.6 m/sec) each, to accomplish a net change in velocity of around 11.5 mph (5.13 m/sec). The mission team will continue to examine telemetry and tracking data over the next week to verify the new trajectory. The maneuver targeted the spacecraft to fly through a corridor designed for the collection of high-resolution images that will be used to build a shape model of Bennu.

    The OSIRIS-REx spacecraft is in the midst of a six-week series of final approach maneuvers. AAM-1 and AAM-2, which executed on Oct. 1 and Oct. 15 respectively, slowed the spacecraft by a total of approximately 1,088 mph (486 m/sec). The last of the burns, AAM-4, is scheduled for Nov. 12 and will adjust the spacecraft’s trajectory to arrive at a position 12 miles (20 km) from Bennu on Dec. 3.

  33. Safety & Science: OSIRIS-REx on the Lookout for Hazards During Approach

    By Christine Hoekenga

    October 17, 2018 -

    An artist’s concept of OSIRIS-REx searching for dust plumes in the vicinity of asteroid Bennu. Credit: University of Arizona

    On Sept. 12, OSIRIS-REx pointed its medium-range science camera, MapCam, toward asteroid Bennu 621,000 miles (one million kilometers) in the distance. Slewing gently side to side and up and down as it captured 64 images, the spacecraft scanned the area around the asteroid in a carefully choreographed pattern. The day before, it had collected a similar mosaic of images with its long-range science camera, PolyCam.

    Over the next few days, scientists on the ground pored over the images, looking for any signs of dust in the vicinity of the asteroid, which could present a hazard to the spacecraft as it approaches. Ultimately, they determined that the coast is clear – for now.

    But OSIRIS-REx will look for natural satellites (small moons) and conduct another search for dust plumes when the spacecraft is closer to Bennu.

    No dust was detected in this MapCam image of the area around Bennu (circled in green) taken Sept. 12, 2018 during OSIRIS-REx’s first Dust Plume Search. Credit: NASA/Goddard/University of Arizona

    While comets, with their characteristic tails and comas, are known for releasing plumes of volatile materials like ice, gas, and dust, this behavior has also been observed in some asteroids. If dust had been visible in the images collected in mid-September, it would have suggested that Bennu had comet-like plume activity in the recent past, probably in the weeks or months before OSIRIS-REx conducted its first dust search.

    Although OSIRIS-REx is designed to withstand the rigors of spaceflight and the occasional collision with stray particles, flying through a dust plume would pose a risk to the spacecraft’s instruments and solar panels. If the mission team had identified plume activity in the images, they had contingency plans to execute a braking maneuver, placing the spacecraft at a safe distance so that the dust activity could be studied further.

    The existence of dust plumes would suggest that Bennu has active deposits of ice or other volatiles. Finding frozen water on the asteroid would be an exciting result for mission scientists who are in part studying Bennu to understand whether asteroids could have been the delivery mechanism for the water and organic materials needed to seed life on Earth billions of years ago. Plumes would also have implications for where OSIRIS-REx could safely collect a sample of material from Bennu’s surface in 2020 – and what types of material would likely be in that sample.

    A view of Comet 67P backlit by the Sun makes plumes coming off the comet’s surface highly visible. Credit: ESA/Rosetta/NAVCAM

    “We probably wouldn’t want to sample too near a vent for safety reasons,” says Carl Hergenrother, the OSIRIS-REx Astronomy Working Group Lead, who helped plan the hazard searches. “But it would be interesting since plumes mean that there could be subsurface volatile material nearby.”

    OSIRIS-REx’s second dust plume search, scheduled for two days in Spring 2019 when the spacecraft will be about 3.1 miles (five kilometers) from Bennu, will look for active dust plumes coming off Bennu’s surface. For those observations, the spacecraft will be positioned between the Sun and the asteroid (at a high phase angle) so that Bennu is backlit and any dust plumes are more visible. Some of the 13 mosaics that the spacecraft captures will include offset images of the asteroid so that any jets coming from the surface are easier to see against the dark backdrop of space.

    Dust isn’t the only potential hazard that OSIRIS-REx is looking out for. Later this fall, the spacecraft will use PolyCam and MapCam to search for natural satellites – any chunk of rock orbiting Bennu that is larger than 10 centimeters and bright enough to be seen (which requires an albedo of at least 0.03). While most asteroids exert a weak gravitational pull due to their relatively small sizes (Bennu has a diameter of roughly 500 meters), they are capable of holding small moons in orbit around themselves. In fact, asteroid 243 Ida, the second asteroid ever visited by a spacecraft, surprised scientists when images from the Galileo mission revealed it had a small moon, now called Dactyl.

    Asteroid Ida and its moon, Dactyl

    243 Ida is the second asteroid visited by a spacecraft (Galileo) and the first found to have its own moon. Credit: NASA/JPL

    To look for moons, two of OSIRIS-REx’s cameras will again capture a series of carefully planned mosaics covering the area around Bennu. First, PolyCam will map the asteroid’s entire Hill Sphere (the area where a satellite could theoretically exist), looking for objects that are one meter or larger. Then, as the spacecraft gets closer, MapCam will conduct a search pattern for smaller satellites (down to 10 centimeters), which could only exist in a stable orbit closer to Bennu.

    Similar to a dust plume discovery, if OSIRIS-REx were to detect a natural satellite orbiting Bennu, it would trigger a contingency plan. The spacecraft would conduct a braking burn and stop its approach to the asteroid about 40 or 50 kilometers out. The team would then take a few weeks to closely map the moon’s orbit around Bennu and decide whether any changes need to be made to the mission plan for the spacecraft to safely avoid the satellite. Later on, the team would study the moon in more depth, collecting images and other data about its color, reflectivity, shape, size, and other features.

     

    Also similar to a dust plume detection, a moon would be an interesting scientific discovery. “If we did find a satellite, mapping its orbit would allow us to refine the mass of Bennu before going into orbit around the asteroid or even doing close approaches,” says Hergenrother. “It would also tell us more about Bennu’s history.”

    While potential hazards like dust and natural satellites present navigation, safety and other challenges, they are part of the inherent adventure of exploring a never-before-visited world. Although Bennu has been thoroughly studied from Earth, the asteroid may have many surprises in store for the mission team. Careful planning and thorough observation strategies will ensure that these surprises are transformed from potential hazards into new scientific knowledge.

  34. NASA’s OSIRIS-REx Executes Second Asteroid Approach Maneuver

    October 15, 2018 -

    NASA’s OSIRIS-REx spacecraft executed its second Asteroid Approach Maneuver (AAM-2) today. The spacecraft’s main engine thrusters fired in a braking maneuver designed to slow the spacecraft’s speed relative to Bennu from 315 mph (141 m/sec) to 11.8 mph (5.2 m/sec). Likewise, the spacecraft’s approach speed dropped from nearly 7,580 miles (12,200 km) to 280 miles (450 km) per day.

    Artist’s conception of NASA’s OSIRIS-REx spacecraft during a burn of its main engine. Credit: University of Arizona

    The mission team will continue to examine telemetry and tracking data and will have more information over the next week. This burn marked the last planned use of the spacecraft’s main engines prior to OSIRIS-REx’s departure from Bennu in March 2021.

    The OSIRIS-REx spacecraft is in the midst of a six-week series of maneuvers designed to fly the spacecraft through a precise corridor toward Bennu. AAM-1, which executed on Oct. 1, slowed the spacecraft by 785.831 mph (351.298 m/sec) and consumed 532.4 pounds (241.5 kilograms) of fuel. AAM-3 is schedule for October 29. The last of the burns, AAM-4, is scheduled for November 12 and will adjust the spacecraft’s trajectory to arrive at a position 12 miles (20 km) from Bennu on December 3. After arrival, the spacecraft will perform a series of fly-bys over Bennu’s poles and equator.

  35. NASA’s OSIRIS-REx Executes First Asteroid Approach Maneuver

    October 1, 2018 -

    NASA’s OSIRIS-REx spacecraft executed its first Asteroid Approach Maneuver (AAM-1) today putting it on course for its scheduled arrival at the asteroid Bennu in December.

    Artist’s conception of NASA’s OSIRIS-REx spacecraft during a burn of its main engine. Credit: University of Arizona

    The spacecraft’s main engine thrusters fired in a braking maneuver designed to slow the spacecraft’s speed relative to Bennu from approximately 1,100 mph (491 m/sec) to 313 mph (140 m/sec). The mission team will continue to examine telemetry and tracking data as they become available and will have more information on the results of the maneuver over the next week.

    During the next six weeks, the OSIRIS-REx spacecraft will continue executing the series of asteroid approach maneuvers designed to fly the spacecraft through a precise corridor during its final slow approach to Bennu. The last of these, AAM-4, scheduled for November 12, will adjust the spacecraft’s trajectory to arrive at a position 12 miles (20 km) from Bennu on December 3. After arrival, the spacecraft will initiate asteroid proximity operations by performing a series of fly-bys over Bennu’s poles and equator.

  36. NASA’s OSIRIS-REx Begins Asteroid Operations Campaign

    August 24, 2018 -
    Asteroid Bennu moving againts a star field

    On Aug. 17, the OSIRIS-REx spacecraft obtained the first images of its target asteroid Bennu from a distance of 1.4 million miles (2.2 million km), or almost six times the distance between the Earth and Moon. This cropped set of five images was obtained by the PolyCam camera over the course of an hour for calibration purposes and in order to assist the mission’s navigation team with optical navigation efforts. Bennu is visible as a moving object against the stars in the constellation Serpens.

    After an almost two-year journey, NASA’s asteroid sampling spacecraft, OSIRIS-REx, caught its first glimpse of asteroid Bennu last week and began the final approach toward its target. Kicking off the mission’s asteroid operations campaign on Aug. 17, the spacecraft’s PolyCam camera obtained the image from a distance of 1.4 million miles (2.2 million km).

    OSIRIS-REx is NASA’s first mission to visit a near-Earth asteroid, survey the surface, collect a sample and deliver it safely back to Earth. The spacecraft has traveled approximately 1.1 billion miles (1.8 billion km) since its Sept. 8, 2016, launch and is scheduled to arrive at Bennu on Dec. 3.

    “Now that OSIRIS-REx is close enough to observe Bennu, the mission team will spend the next few months learning as much as possible about Bennu’s size, shape, surface features, and surroundings before the spacecraft arrives at the asteroid,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “After spending so long planning for this moment, I can’t wait to see what Bennu reveals to us.”

    As OSIRIS-REx approaches the asteroid, the spacecraft will use its science instruments to gather information about Bennu and prepare for arrival.  The spacecraft’s science payload comprises the OCAMS camera suite (PolyCam, MapCam, and SamCam), the OTES thermal spectrometer, the OVIRS visible and infrared spectrometer, the OLA laser altimeter, and the REXIS x-ray spectrometer.

    During the mission’s approach phase, OSIRIS-REx will:

    • regularly observe the area around the asteroid to search for dust plumes and natural satellites, and study Bennu’s light and spectral properties;
    • execute a series of four asteroid approach maneuvers, beginning on Oct. 1, slowing the spacecraft to match Bennu’s orbit around the Sun;
    • jettison the protective cover of the spacecraft’s sampling arm in mid-October and subsequently extend and image the arm for the first time in flight; and
    • use OCAMS to reveal the asteroid’s overall shape in late-October and begin detecting Bennu’s surface features in mid-November.

    After arrival at Bennu, the spacecraft will spend the first month performing flybys of Bennu’s north pole, equator, and south pole, at distances ranging between 11.8 and 4.4 miles (19 and 7 km) from the asteroid. These maneuvers will allow for the first direct measurement of Bennu’s mass as well as close-up observations of the surface. These trajectories will also provide the mission’s navigation team with experience navigating near the asteroid.

    “Bennu’s low gravity provides a unique challenge for the mission,” said Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “At roughly 0.3 miles [500 meters] in diameter, Bennu will be the smallest object that any spacecraft has ever orbited.”

    The spacecraft will extensively survey the asteroid before the mission team identifies two possible sample sites. Close examination of these sites will allow the team to pick one for sample collection, scheduled for early July 2020. After sample collection, the spacecraft will head back toward Earth before ejecting the Sample Return Capsule for landing in the Utah desert in Sept. 2023.

    NASA’s Goddard Space Flight Center provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for its Science Mission Directorate in Washington.

  37. Successful Second Deep Space Maneuver for OSIRIS-REx Confirmed

    July 3, 2018 -

    New tracking data confirms that NASA’s OSIRIS-REx spacecraft successfully completed its second Deep Space Maneuver (DSM-2) on June 28. The thruster burn put the spacecraft on course for a series of asteroid approach maneuvers to be executed this fall that will culminate with the spacecraft’s scheduled arrival at asteroid Bennu on Dec. 3.

    Artist’s conception of NASA’s OSIRIS-REx spacecraft during a burn of its TCM thrusters. Credit: University of Arizona

    The DSM-2 burn, which employed the spacecraft’s Trajectory Correction Maneuver (TCM) thruster set, resulted in a 37 miles per hour (16.7 meters per second) change in the vehicle’s velocity and consumed 28.2 pounds (12.8 kilograms) of fuel.

    Tracking data from the Deep Space Network provided preliminary confirmation of the burn’s execution, and the subsequent downlink of telemetry from the spacecraft shows that all subsystems performed as expected.

    DSM-2 was OSIRIS-REx’s last deep space maneuver of its outbound cruise to Bennu. The next engine burn, Asteroid Approach Maneuver 1 (AAM-1), is scheduled for early October. AAM-1 is a major braking maneuver designed to slow the spacecraft’s speed from approximately 1,130 to 320 miles per hour (506.2 to 144.4 meters per second) relative to Bennu and is the first of four asteroid approach maneuvers scheduled for this fall.

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s observation planning and processing. Lockheed Martin Space in Denver built the spacecraft and is providing spacecraft flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for its Science Mission Directorate in Washington.

  38. OSIRIS-REx Executes Second Deep Space Maneuver

    June 28, 2018 -

    Artist’s conception of NASA’s OSIRIS-REx spacecraft during a burn of its TCM thrusters. Credit: University of Arizona

    NASA’s OSIRIS-REx spacecraft executed its second Deep Space Maneuver today, which put the spacecraft on course for its scheduled arrival at the asteroid Bennu in December. The mission team will continue to examine telemetry and tracking data as they become available and will have more information on the results of the maneuver over the next week.

  39. Two Pieces of a Cosmic Puzzle: Hayabusa2 and OSIRIS-REx

    By Christine Hoekenga

    June 22, 2018 -

    It began with dust. Before there were asteroids, or planets, or people – about 4.6 billion years ago – a cloud of dust and gas swirled in the cosmos. At the center, a star began to form.

    With heat and shock waves, clumps of this ancient dust coalesced into droplets of molten rock called chondrules. These chondrules and dust became the building blocks of the Solar System. Eventually, chunks of material as large as asteroids, and even planets, formed from this cloud and organized according to the laws of physics around a newly born star: our Sun.

    Scientists believe one of these chunks became a protoplanet that eventually broke apart in a collision, giving rise to an asteroid that humans would one-day dub Bennu. Another (or perhaps the same) chunk produced another asteroid that would become known as Ryugu. Long before humans were around to give them names or contemplate their origins, both asteroids migrated from the asteroid belt between Mars and Jupiter into near-Earth space and settled into new orbits.

    It wasn’t until hundreds of millions of years later, in the 1800s, that human astronomers trained their telescopes on the sky and began identifying and studying asteroids. Fast forward to 1999. That year, the Lincoln Near-Earth Asteroid Research (LINEAR) survey discovered two near-Earth asteroids that would go on to become the targets for two robotic sample return missions: NASA’s OSIRIS-REx, launched in 2016 to study asteroid Bennu, and the Japanese Aerospace Exploration Agency’s Hayabusa2, launched in 2014 to study Ryugu.

    Even though humans have intently studied asteroids for centuries, we have had very few opportunities to get our hands on material directly from these cosmic time capsules. Meteorites, which are pieces of asteroids that have fallen to Earth, provide important clues about the early days of the Solar System, but they have two major limitations. First, scientists aren’t certain which parent bodies (asteroids) gave rise to most of them. Second, they are not clean, unaltered samples. After withstanding the heat of atmospheric entry, they land on the ground, where they become contaminated with materials from Earth and immediately begin to corrode.

    The only sample humanity has ever collected directly from an asteroid came back with JAXA’s Hayabusa Mission in 2010. That sample contains less than a milligram of particles from Itokowa, a “stony” asteroid with high silica content.

    Soon, though, we’ll have two new opportunities to study pristine asteroid material. This time the samples will come from the carbon-rich asteroids Bennu and Ryugu. These asteroids are of particular interest because they contain the very oldest material from the stellar nursery – and because carbon-bearing compounds are the basis of life as we know it. These samples, and the organic molecules they contain, will help shed light on some of humanity’s grand mysteries: Where did we come from? How did life develop on Earth?

    Both spacecraft will reach their respective destinations during 2018 – Hayabusa2 in June and OSIRIS-REx in December – and the missions fit together like two adjoining pieces of a cosmic puzzle. In combination, the data and discoveries from these two asteroid explorers will reveal a long-shrouded portion of the Solar System’s portrait.

    Mapping, navigating around, and collecting samples from small Solar System bodies are all relatively new endeavors for humanity, and the two mission teams have already been sharing ideas, data, and lessons learned for several years as part of a major partnership between NASA and JAXA. This exchange will continue as the two spacecraft operate in close proximity to their target asteroids. The OSIRIS-REx team will host Japanese scientists in the Science Operations Center at the University of Arizona, and OSIRIS-REx team members will travel to JAXA during Hayabusa2’s operations. They will share software, data, techniques for analysis, and aspects of each other’s cultural systems in the process. Ultimately, the two agencies will exchange portions of the returned samples as well.

    However, the two missions’ strategies for exploration are quite different. For starters, OSIRIS-REx will go into orbit around Bennu during two separate phases of asteroid operations. All told, the NASA spacecraft will spend more than a year and a half imaging and mapping Bennu with its suite of remote sensing instruments (cameras, spectrometers, and a laser altimeter) – a plan based partially on lessons learned from JAXA’s first Hayabusa mission. All of this data will be used to select a single sample site with high scientific interest and low risk to the spacecraft. After carefully rehearsing, OSIRIS-REx will move in close, extend its sampling arm, and touch the asteroid’s surface for just five seconds, using nitrogen gas to stir up and collect at least 60 grams of loose material.

    By contrast, Hayabusa2 will not actually orbit Ryugu. In fact, the JAXA spacecraft will spend only about three months mapping before it begins the process of collecting three separate, but smaller, samples from different geographic locations on Ryugu. In addition to remote sensing, Hayabusa2 will deploy a lander (called MASCOT) and two rovers (called MINERVA-II 1 and 2) and will use a projectile and small explosive during one sampling process to collect material from beneath the asteroid’s surface.

    Despite the differences, there are shared challenges, and both teams’ learning curves will be steep. Until now, neither asteroid has been seen up close, and they will likely have some surprises in store. The predictions made from the ground about their shapes, sizes, and compositions could turn out to be wrong. Ryugu is expected to be about 80 percent larger than Bennu (approximately 900 meters in diameter versus 500 meters in diameter), but both asteroids are much smaller than the planets and most other bodies that have been orbited or landed on by spacecraft. The small size and microgravity environment makes navigation and sampling that much more challenging.

    Both spacecraft are venturing into far-away and unknown territory and attempting feats that are new to humanity. For the most part, they will be on their own on the asteroid frontier, but the value of running complementary missions cannot be overstated. The scientific and cultural returns from the two missions combined is far more than double the value of each individual mission. The ability to make comparisons during planning, operations, and after the samples are returned reduces risk and make both missions exponentially better.

    And, like any expedition, the chances for success increase when there are two friendly explorers forging similar paths and learning side-by-side.

  40. Asteroid Bennu, as Seen from Earth

    By Christine Hoekenga

    May 1, 2018 -

    When Asteroid Bennu was discovered on Sept. 11, 1999 by the Lincoln Near-Earth Asteroid Research project (LINEAR), it was called 1999 RQ36 — a provisional designation assigned by the Minor Planet Center. After follow-up observations determined the asteroid’s precise orbit, it was issued the official number 101955, indicating that it was the 101,955th asteroid to be officially recognized.

    Bennu’s orbit brings it relatively close to Earth every six years (in 2018, for example, the asteroid comes within 0.352 AU or about 33 million miles), giving astronomers better opportunities to image the asteroid with telescopes. Additional ground-based observations of Bennu have been made a number times since the asteroid’s discovery, including these images captured by telescopes based in Arizona:

    Image of Asteroid Bennu from Earth Sept. 2005

    Sept. 17, 2005 — Six years after its discovery, Bennu was was observed by researchers using the 1.5-meter Kuiper Telescope at the University of Arizona. Credit: Carl Hergenrother/University of Arizona

     

     

    Image of Asteroid Bennu from Earth Sept. 2011

    Sept. 26, 2011 — A few months after NASA selected the OSIRIS-REx mission for funding to visit and sample Bennu, researchers using the 1.5-meter Kuiper Telescope at the University of Arizona observed the asteroid. Credit: Carl Hergenrother/University of Arizona

     

     

    Image of Asteroid Bennu from Earth May 2012

    April 20, 2012 — Researchers using the 1.5-meter Kuiper Telescope at the University of Arizona observed Bennu again in the spring of 2012. Credit: Carl Hergenrother/University of Arizona

     

     

    Image of Asteroid Bennu from Earth May 2012

    May 15, 2012 — Bennu was observed using the 1.8-meter Vatican Advanced Technology Telescope (VATT) on Mount Graham in Arizona in May 2012. Credit: Carl Hergenrother/University of Arizona/Vatican Observatory

     

    Scientists have also used radar data from the Arecibo Observatory in Puerto Rico and NASA’s Deep Space Network antenna in California to estimate Bennu’s shape and size. However, to this day, no one has ever seen or imaged the asteroid up close.

    That’s where OSIRIS-REx comes in.

    Starting in the summer of 2018, the spacecraft will begin imaging asteroid Bennu with its PolyCam imager. The first images will be similar to ground-based observations: the asteroid will appear as a point of light in the distance. As the spacecraft approaches Bennu, the images will become clearer and more detailed, eventually zooming in on the asteroid’s precise shape, size and surface features.

    The mission team will use these detailed images, along with data collected by the spacecraft’s other instruments, to create maps of Bennu and, ultimately to select the location where OSIRIS-REx will collect a sample of its surface material for return to Earth in 2023.

     

  41. A long, long way from home…

    February 14, 2018 -

     

    The OSIRIS-REx spacecraft captured this image of the Earth and Moon system using its NavCam1 imager on January 17 from a distance of 39.5 million miles (63.6 million km). Earth is the largest, brightest spot in the center of the image, with the smaller, dimmer Moon appearing to the right. Credit: NASA/Goddard/University of Arizona/Lockheed Martin

    As part of an engineering test, the OSIRIS-REx spacecraft captured this image of the Earth and Moon using its NavCam1 imager on January 17 from a distance of 39.5 million miles (63.6 million km).  When the camera acquired the image, the spacecraft was moving away from home at a speed of 19,000 miles per hour (8.5 kilometers per second).

    Earth is the largest, brightest spot in the center of the image, with the smaller, dimmer Moon appearing to the right. Several constellations are also visible in the surrounding space. The bright cluster of stars in the upper left corner is the Pleiades in the Taurus constellation. Hamal, the brightest star in Aries, is located in the upper right corner of the image.  The Earth-Moon system is centered in the middle of five stars comprising the head of Cetus the Whale.

    NavCam1, a grayscale imager, is part of the TAGCAMS (Touch-And-Go Camera System) navigation camera suite.  Malin Space Science Systems designed, built, and tested TAGCAMS; Lockheed Martin integrated TAGCAMS to the OSIRIS-REx spacecraft and operates TAGCAMS.

     

  42. NASA Selects Participating Scientists to Join OSIRIS-REx Mission

    December 8, 2017 -

    NASA selected 13 Participating Scientists from a range of disciplines to join the OSIRIS-REx mission. Credit: University of Arizona

    NASA has selected 13 participating scientists for the agency’s first asteroid sample return mission, OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer).

    The goal of the OSIRIS-REx Participating Scientist Program is to enhance the scientific return during the asteroid-operational phase of the mission by expanding participation in the mission through new investigations that broaden and/or complement existing investigations. The participating scientists will become science team members during their three-year tenure with the mission.

    OSIRIS-REx launched Sept. 8, 2016, from Cape Canaveral, Florida. It’s currently on a seven-year journey to rendezvous with, study, and return a sample of Bennu to Earth. This sample of a primitive asteroid will help scientists understand the formation of our solar system more than 4.5 billion years ago.

    The spacecraft will arrive at Bennu in December 2018, and begin surveying the surface.

    The newly selected participating scientists are:

    • Joshua Bandfield – Space Science Institute, Boulder, Colorado
    • Kerri Donaldson-Hanna – University of Oxford, England
    • Catherine Elder – Jet Propulsion Laboratory, Pasadena, California
    • Timothy Glotch – Stony Brook University (SUNY), New York
    • Romy Hanna – University of Texas, Austin
    • Christine Hartzell – University of Maryland, College Park
    • Jamie Molaro – Planetary Science Institute, Tucson, Arizona
    • Greg Neumann – NASA’s Goddard Space Flight Center, Greenbelt, Maryland
    • Maurizio Pajola – INAF/Astronomical Observatory of Padua, Italy
    • Stephen Schwartz – University of Arizona, Tucson
    • Matthew Siegler – Planetary Science Institute, Tucson, Arizona
    • David Trang – University of Hawaii, Manoa
    • Pasquale Tricarico – Planetary Science Institute, Tucson, Arizona

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space Systems in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for the Science Mission Directorate in Washington.

  43. OSIRIS-REx Images Earth and the Moon in Color

    October 10, 2017 -

     

    OSIRIS-REx MapCam Color Image Earth and Moon

    A color portrait of the Earth and the Moon taken Oct. 2, 2017 at a distance of approximately 3,180,000 miles (5,120,000 km) from Earth, using OSIRIS-REx’s MapCam imager. To produce the image, three of MapCam’s color filters (blue, green and red) were co-registered and stacked. Color correction and “stretching” (brightening) were performed on the Earth and Moon. Credit: NASA/Goddard/University of Arizona

     

    This color composite image of Earth and the Moon was taken Oct. 2, 2017 (ten days after OSIRIS-REx performed its Earth Gravity Assist maneuver), using MapCam, the mid-range scientific camera onboard the spacecraft. The distance to Earth was approximately 3,180,000 miles (5,120,000 km)—or about 13 times the distance between the Earth and Moon.

    MapCam, part of the OSIRIS-REx Camera Suite (OCAMS) operated by the University of Arizona, has four color filters. To produce this image, three of them (b, v and w) were treated as a blue-green-red triplet, co-registered and stacked. The Earth and Moon were each color-corrected, and the Moon was “stretched” (brightened) to make it more easily visible.

     

    Graphic - MapCam Imaging Earth and Moon After EGA

    Credit: NASA/Goddard/University of Arizona

    To capture the image, OSIRIS-REx pointed its instrument deck back toward Earth from a distance of approximately 3,180,000 miles (5,120,000 km). At that range, the Moon—which was 3,370,000 miles (5,420,000 km) away from the spacecraft—appeared just inside MapCam’s field of view, allowing both planetary bodies to be captured in the same frame.

  44. OSIRIS-REx Images the Moon

    October 3, 2017 -

    On Sept. 25, 2017, the OSIRIS-REx spacecraft obtained the data used to produce this image of the Moon with its high-resolution PolyCam imager. Credit: NASA/Goddard/University of Arizona

    Three days after its Earth flyby, the OSIRIS-REx spacecraft examined the Moon using its high-resolution PolyCam imager. This image was produced using data taken Sept. 25, when the spacecraft was approximately 746,000 miles (1.2 million km) from the Moon, moving away at approximately 14,000 miles per hour (22,530 km per hour).

    Familiar lunar features such as the Mare Tranquillitatis (Sea of Tranquility) and Mare Crisium (Sea of Crises) are visible on the left. Also visible are features of the far side of the Moon, such as the mare plain surrounding Tsiolkovsky Crater (bottom right) and the bright ray systems surrounding the Giordano Bruno and Necho Craters (center). To produce this image, the OSIRIS-REx team registered and combined nine one-megapixel PolyCam images taken in quick succession using a technique called super-resolution imaging.

    PolyCam is part of the OSIRIS-REx Camera Suite (OCAMS) operated by the University of Arizona.

  45. NASA’s OSIRIS-REx Snaps Pictures of Earth and the Moon

    September 28, 2017 -

    The first image taken by NASA’s OSIRIS-REx spacecraft after completion of its Earth Gravity Assist maneuver on Sept. 22, 2017. Credit: NASA/Goddard/University of Arizona/Lockheed Martin

    The first image taken by NASA’s OSIRIS-REx spacecraft after completion of its Earth Gravity Assist maneuver on Sept. 22, 2017, cropped to show in greater detail the spacecraft’s view of Earth from 69,000 miles (110,000 kilometers). The image has been rotated so that Earth’s north pole is located at the top, and the Baja Peninsula is visible above and to the right of center. Cloud cover and the Pacific Ocean dominate most of the image, but Hurricane Maria and the remnants of Hurricane Jose can be seen in the far upper-right portion of the image, off the east coast of the United States. This image was captured by NavCam 1, a black-and-white imager that is one of three cameras comprising TAGCAMS (the Touch-and-Go Camera System), which is part of OSIRIS-REx’s guidance, navigation, and control system. NavCam images will track starfields and landmarks on Bennu to determine the spacecraft position during mission operations. TAGCAMS was designed, built and tested by Malin Space Science Systems; Lockheed Martin integrated TAGCAMS to the OSIRIS-REx spacecraft and operates TAGCAMS. Credit: NASA/Goddard/University of Arizona/Lockheed Martin

     

    This black-and-white image of the Earth-Moon system was captured on Sept. 25, 2017 by NavCam 1. Credit: NASA/Goddard/University of Arizona/Lockheed Martin

    This black-and-white image of the Earth-Moon system was captured on Sept. 25, 2017 by NavCam 1, one of three cameras that comprise TAGCAMS (the Touch-and-Go Camera System) on NASA’s OSIRIS-REx spacecraft. At the time this image was taken, the spacecraft was retreating from Earth after performing an Earth Gravity Assist maneuver on Sept. 22. Earth and the Moon are shown 249,000 miles (401,200 kilometers) apart, and the spacecraft is 804,000 miles (1,297,000 kilometers) from Earth and 735,000 miles (1,185,000 kilometers) from the Moon.  TAGCAMS was designed, built and tested by Malin Space Science Systems; Lockheed Martin integrated TAGCAMS to the OSIRIS-REx spacecraft and operates TAGCAMS. Credit: NASA/Goddard/University of Arizona/Lockheed Martin

  46. OSIRIS-REx Views the Earth During Flyby

    September 26, 2017 -

    A color composite image of Earth taken on Sept. 22 by the MapCam camera on NASA’s OSIRIS-REx spacecraft. Credit: NASA/Goddard/University of Arizona

    A color composite image of Earth taken on Sept. 22 by the MapCam camera on NASA’s OSIRIS-REx spacecraft. This image was taken just hours after the spacecraft completed its Earth Gravity Assist at a range of approximately 106,000 miles (170,000 kilometers). MapCam is part of the OSIRIS-REx Camera Suite (OCAMS) operated by the University of Arizona. Visible in this image are the Pacific Ocean and several familiar landmasses, including Australia in the lower left, and Baja California and the southwestern United States in the upper right. The dark vertical streaks at the top of the image are caused by short exposure times (less than three milliseconds). Short exposure times are required for imaging an object as bright as Earth, but are not anticipated for an object as dark as the asteroid Bennu, which the camera was designed to image.

     

    OVIRS captured this visible and infrared spectral curve, which shows the amount of sunlight reflected from the Earth, after the spacecraft’s Earth Gravity Assist on Sept. 22, 2017. Credit: NASA/Goddard/University of Arizona

    OVIRS, the OSIRIS-REx Visible and Infrared Spectrometer, captured this visible and infrared spectral curve, which shows the amount of sunlight reflected from the Earth, hours after the spacecraft’s closest approach during Earth Gravity Assist on Sept. 22 2017. The features in the curve are caused by solar absorption due to different substances (water vapor, carbon dioxide, and oxygen). The smooth red curve is the spectrum of the sun and shows what would be reflected if there these substances were not present in the atmosphere. OVIRS was built and is operated by NASA’s Goddard Space Flight Center in Greenbelt, Md.  The inset shows an image of Earth captured by OCAMS on the same date showing the approximate location of the “spot” (400 kilometers in diameter) on the Earth that was scanned by the OVIRS instrument to produce this spectral curve.

     

     

     

     

     

    OTES captured these infrared spectral curves during Earth Gravity Assist on Sept. 22 2017, hours after the spacecraft’s closest approach. Credit: NASA/Goddard/University of Arizona/Arizona State University

    OTES, the OSIRIS-REx Thermal Emission Spectrometer, captured these infrared spectral curves during Earth Gravity Assist on Sept. 22 2017, hours after the spacecraft’s closest approach. The peaks and valleys in the curves are known as absorption features and show differences in absorption of the sun’s energy due to different substances (water vapor, carbon dioxide, methane and ozone) in Earth’s atmosphere. The curves also provide temperature information for different heights in the atmosphere. The smooth red and blue curves show the temperatures of the ocean surface and the stratosphere without the effects of the absorption features. OTES was built and is operated by Arizona State University in Tempe, Ariz.  The inset shows an image of Earth captured by OCAMS on the same date shows the approximate locations and sizes of the “spots” (each 800 kilometers in diameter) on the Earth that were scanned by the OTES instrument to produce these spectral curves.

  47. NASA’S OSIRIS-REx Spacecraft Slingshots Past Earth

    September 22, 2017 -

    NASA’s asteroid sample return spacecraft successfully used Earth’s gravity on Friday to slingshot itself on a path toward the asteroid Bennu, for a rendezvous next August.

    At 12:52 p.m. EDT on Sept. 22, the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer) spacecraft came within 10,711 miles (17,237 km) of Antarctica, just south of Cape Horn, Chile, before following a route north over the Pacific Ocean.

    OSIRIS-REx launched from Cape Canaveral Air Force Station in Florida on Sept. 8, 2016, on an Atlas V 411 rocket. Although the rocket provided the spacecraft with all the momentum required to propel it forward to Bennu, OSIRIS-REx needed an extra boost from the Earth’s gravity to change its orbital plane. Bennu’s orbit around the Sun is tilted six degrees from Earth’s orbit, and this maneuver changed the spacecraft’s direction to put it on the path toward Bennu.

    As a result of the flyby, the velocity change to the spacecraft was 8,451 miles per hour (3.778 kilometers per second).

    “The encounter with Earth is fundamental to our rendezvous with Bennu,” said Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “The total velocity change from Earth’s gravity far exceeds the total fuel load of the OSIRIS-REx propulsion system, so we are really leveraging our Earth flyby to make a massive change to the OSIRIS-REx trajectory, specifically changing the tilt of the orbit to match Bennu.”

    The mission team also is using OSIRIS-REx’s Earth flyby as an opportunity to test and calibrate the spacecraft’s instrument suite. Approximately four hours after the point of closest approach, and on three subsequent days over the next two weeks, the spacecraft’s instruments will be turned on to scan Earth and the Moon. These data will be used to calibrate the spacecraft’s science instruments in preparation for OSIRIS-REx’s arrival at Bennu in late 2018.

    “The opportunity to collect science data over the next two weeks provides the OSIRIS-REx mission team with an excellent opportunity to practice for operations at Bennu,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “During the Earth flyby, the science and operations teams are co-located, performing daily activities together as they will during the asteroid encounter.”

    The OSIRIS-REx spacecraft is currently on a seven-year journey to rendezvous with, study, and return a sample of Bennu to Earth. This sample of a primitive asteroid will help scientists understand the formation of our solar system more than 4.5 billion years ago.

    NASA’s Goddard Space Flight Center provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space Systems in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for the Science Mission Directorate in Washington.

  48. Large Binocular Telescope Snags First Glimpse of NASA’s OSIRIS-REx Spacecraft Since Launch

    September 8, 2017 -

    This set of magnified, cropped images shows NASA’s OSIRIS-REx spacecraft (highlighted in red) as it approaches Earth for its Sept. 22 Earth Gravity Assist. To improve visibility, the images have been inverted so that black and white are reversed. The images were taken Sept. 2, by the Large Binocular Telescope Observatory located on Mount Graham in Arizona. This is the first Earth-based view of the spacecraft since its launch on Sept. 8, 2016.

    On Sept. 2, 2017, the Large Binocular Telescope on Mt. Graham, Ariz., imaged the OSIRIS-REx spacecraft as the spacecraft approached Earth. This is the first Earth-based view of the spacecraft since its launch on Sept. 8, 2016. Credit: Large Binocular Telescope Observatory

    OSIRIS-REx, which was approximately 7 million miles (12 million kilometers) away when the images were taken, appears at approximately 25th magnitude.

    The Large Binocular Telescope is a pair of 8.4-meter mirrors mounted side by side on the same mount, that can work together to provide resolution equivalent to a 22.7-meter telescope. The telescope typically conducts imaging of more distant objects but took this opportunity to look for OSIRIS-REx with a pair of wide-field cameras (one per mirror) as the spacecraft approaches Earth for its gravity assist. This encounter will change the spacecraft’s trajectory and set it on course to rendezvous with asteroid Bennu, where it will collect a sample of surface material and return it to Earth for study in 2023. The Large Binocular Telescope Observatory is headquartered on the Tucson campus of the University of Arizona.

    The OSIRIS-REx mission team is collecting other images of the spacecraft taken by observatories and other ground-based telescopes around the world during this period – approximately Sept. 10-23, depending on location and local conditions. Individuals and groups may submit images of the spacecraft via the mission’s website, where instructions to locate the spacecraft in the sky are also available.

    For more information on the OSIRIS-REx mission, visit:

    www.nasa.gov/osirisrex  and www.asteroidmission.org

    For more information on the Large Binocular Telescope, visit:

    www.lbto.org

  49. Spot the Spacecraft

    September 6, 2017 -

    On Sept. 22, NASA’s OSIRIS-REx spacecraft will make a close approach to Earth, using the planet’s gravity to slingshot itself toward the asteroid Bennu. Over the course of several days, observatories and amateur astronomers with specialized equipment will be able to see OSIRIS-REx as the spacecraft approaches and retreats from its closest position over Earth, approximately 11,000 miles (17,000 km) above the planet’s surface.

    The mission will collect images of OSIRIS-REx taken by observatories and other ground-based telescopes around the world during this period – approximately Sept. 10-23, depending on location and local conditions. Observers from the OSIRIS-REx Target Asteroids! citizen science program, who regularly volunteer their time to help scientists study near-Earth asteroids, will be among those who train their telescopes on the spacecraft’s path.

    “The opportunity to capture images of the OSIRIS-REx spacecraft as it approaches Earth provides a unique challenge for observers to hone their skills during this historic flyby,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “As the spacecraft approaches Earth for its own imaging campaign, ground-based observers will also be looking up and taking photos from the opposite perspective.”

    Individuals and groups may submit images of the spacecraft via the mission’s website, where instructions to locate the spacecraft in the sky are also available.

    “The team is eager and ready to execute the Earth Gravity Assist,” said Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center in Greeenbelt, Maryland. “Not only will it be a significant change in trajectory putting OSIRIS-REx on track for rendezvous with Bennu, it also represents a unique opportunity for the OSIRIS-REx instruments to observe our home planet. It is fantastic that ground based observers are also taking the opportunity to image OSIRIS-REx.”

    The images collected during the Earth gravity assist represent the last opportunity for Earth-based observers to see the spacecraft — until it returns to Earth in 2023 carrying a sample from asteroid Bennu.

    The Japan Aerospace Exploration Agency (JAXA), the home institution of several OSIRIS-REx science team members, will also work with the Japan Public Observatory Society and the Planetary Society of Japan to collect imagery from vantage points in Japan.

    Shortly before OSIRIS-REx reaches its closest distance from Earth, the spacecraft will fly over the eastern half of Australia, giving observers there some of the best opportunities to see and photograph the spacecraft. The Desert Fireball Network — an organization based at Curtin University, Perth, that studies meteorites, fireballs and their pre-Earth orbits—will deploy observers to locations around Australia to track OSIRIS-REx across the sky.

    Members of the public without telescopes can still celebrate the Earth Gravity Assist by joining the “Wave to OSIRIS-REx” social media campaign. Individuals and groups from anywhere in the world are encouraged to take photos of themselves waving to OSIRIS-REx, share them using the hashtag #HelloOSIRISREx and tag the mission account in their posts on Twitter (@OSIRISREx) or Instagram (@OSIRIS_REx).

    Participants may begin taking and sharing photos at any time — or wait until the OSIRIS-REx spacecraft makes its closest approach to Earth at 12:52 p.m. EDT on Friday, Sept. 22.

    NASA’s Goddard Space Flight Center provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s observation planning and processing. Lockheed Martin Space Systems in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for its Science Mission Directorate in Washington.

  50. NASA’s Asteroid-Bound Spacecraft to Slingshot Past Earth

    August 31, 2017 -

    NASA’s asteroid sample return mission, OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer), will pass about 11,000 miles (17,000 kilometers) above Earth just before 12:52 p.m. EDT on Friday, Sept. 22. Using Earth as a slingshot, the spacecraft will receive an assist to complete its journey to the asteroid Bennu.

    This artist’s concept shows the OSIRIS-REx spacecraft passing by Earth.
    Credits: NASA’s Goddard Space Flight Center/University of Arizona

    OSIRIS-REx is undertaking a challenging mission to visit the near-Earth asteroid, survey the surface, collect samples and deliver them safely back to Earth. This is the first NASA mission to attempt such an undertaking. The spacecraft is halfway through its two-year outbound journey, and now OSIRIS-REx needs an extra boost to successfully rendezvous with Bennu.

    Bennu’s orbit around the Sun is tilted six degrees in comparison to Earth’s. The gravity assist will change OSIRIS-REx’s trajectory to put the spacecraft on a course to match the asteroid’s path and speed.

    “The Earth Gravity Assist is a clever way to move the spacecraft onto Bennu’s orbital plane using Earth’s own gravity instead of expending fuel,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson.

    The team has already made multiple adjustments to the spacecraft’s path since launch on Sept. 8, 2016. The largest was a deep space maneuver on Dec. 28, 2016, that changed the speed and path of the spacecraft to target Earth for the flyby. There have also been three trajectory correction maneuvers – one on Oct. 7, 2016, one on Jan. 18, 2017, and another on Aug. 23, 2017 (30 days before the gravity assist) – that further refined the spacecraft’s trajectory in preparation for the flyby.

    The navigation team comprises employees from NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and KinetX Aerospace. KinetX Aerospace navigation team members plan and carry out all OSIRIS-REx maneuvers with the Lockheed Martin spacecraft operations team at the Lockheed Martin Waterton Campus in Littleton, Colorado. To properly target the Earth Gravity Assist, the navigation team calculates any required amount of change in the spacecraft’s course and speed. This information is then translated by the operations team into commands that are uploaded to the spacecraft and executed by firing the spacecraft’s rocket engines.

    After traveling almost 600 million miles, OSIRIS-REx will approach Earth at a speed of about 19,000 mph. The spacecraft will fly over Australia before reaching its closest point to Earth over Antarctica, just south of Cape Horn, Chile.

    “For about an hour, NASA will be out of contact with the spacecraft as it passes over Antarctica,” said Mike Moreau, the flight dynamics system lead at Goddard. “OSIRIS-REx uses the Deep Space Network to communicate with Earth, and the spacecraft will be too low relative to the southern horizon to be in view with either the Deep Space tracking station at Canberra, Australia, or Goldstone, California.”

    NASA will regain communication with OSIRIS-REx at 1:40 p.m. EDT, roughly 50 minutes after closest approach.

    At 4:52 p.m. EDT, four hours after closest approach, OSIRIS-REx will begin science observations of Earth and the Moon to calibrate its instruments.

    During the gravity assist, OSIRIS-REx will pass through a region of space that is inhabited by Earth-orbiting satellites, and NASA has taken precautions to ensure the safety of the spacecraft as it flies through this area. The mission’s flight dynamics team designed a small maneuver that, if necessary, could be executed a day before closest approach to change the spacecraft’s trajectory slightly to avoid a potential collision between OSIRIS-REx and a satellite.

    “A few weeks after the flyby we will assess the outgoing trajectory on its way to Bennu,” said Dan Wibben, the maneuver design and trajectory analysis lead from KinetX Aerospace. “There is a maneuver planned in case we need to adjust the orbit just a little bit to push the spacecraft back on track.”

    In late June of 2018, the team will perform another deep space maneuver to further target the rendezvous with Bennu. Then beginning in October 2018, a series of asteroid approach maneuvers will be executed to slow the spacecraft with respect to the asteroid.

    Once OSIRIS-REx rendezvous with Bennu in late 2018, the spacecraft will begin surveying the surface.

    “The asteroid’s small size and low gravity makes OSIRIS-REx the most challenging mission that I have worked on,” said Peter Antreasian, the navigation team chief from KinetX Aerospace. “At roughly 500 meters in diameter, Bennu will be the smallest object that NASA has orbited.”

    While the engineering team is busy carrying out the Earth Gravity Assist, the mission invites members of the public to mark the occasion by participating in the Wave to OSIRIS-REx social media campaign. Individuals and groups from anywhere in the world are encouraged to take photos of themselves waving to OSIRIS-REx, share them using the hashtag #HelloOSIRISREx and tag the mission account in their posts on Twitter (@OSIRISREx) or Instagram (@OSIRIS_REx).

    Participants may begin taking and sharing photos at any time—or wait until the OSIRIS-REx spacecraft makes its closest approach to Earth at 12:52p.m. EDT on Friday, Sept. 22.

    NASA’s Goddard Space Flight Center provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space Systems in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for its Science Mission Directorate in Washington.

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