Mar 11, 2019
The spacecraft is now operating successfully in the Detailed Survey: Baseball Diamond Phase. Each week during this phase the spacecraft will execute a flyby of Bennu at a different observing angle in order to fully map the asteroid. On March 5, the spacecraft executed the M2D maneuver to commence the first observation leg, a flyby at a local solar time of 12:30 pm and a closest approach distance of 5 km. Both the PolyCam camera and the OTES spectrometer were both on and took observations during this pass of Bennu.
Mar 04, 2019
On Feb. 28, shortly after completing its 23rd orbit of Bennu, the spacecraft executed a departure maneuver (M0D) to exit orbit and fly to a point 7 km from Bennu. Later this week, the spacecraft will begin the series of 3 – 5 km flybys of Bennu that comprise the Detailed Survey mission phase.
This last week the following science instruments took observations of Bennu: OCAMS, OLA, OTES, and REXIS.
Feb 25, 2019
OSIRIS-REx continues to orbit Bennu at an altitude ranging from 1.6 to 2.1 km, with an orbital period of ~62 hours. This last week, both the OLA altimeter and the MapCam camera made observations of Bennu from orbit.
On Feb. 21, the mission team gathered to watch JAXA’s Hayabusa-2 spacecraft execute its first sample collection activity at asteroid Ryugu. The OSIRIS-REx and Hayabusa-2 teams are working closely together on the two asteroid sample return missions, and the OSIRIS-REx team cheered the Japanese announcement that their attempt appeared to be a success.
Feb 18, 2019
This last week, the spacecraft continued orbiting Bennu as part of the mission’s Orbital A phase. The OLA instrument executed a linear scan over the majority of Bennu’s northern hemisphere on Feb. 13. OLA took a single 5 ½ hr scan and received 1.82 million measurements of Bennu.
The mission team is currently in the midst of the biannual checkouts and calibrations of the spacecraft’s systems. So far, TAGCAMS, GNC LIDAR-1 and-2 and REXIS have all been successfully exercised. The checkouts also provided REXIS with the first opportunity to observe Bennu. REXIS science operations are scheduled to begin this summer.
Feb 11, 2019
Several times since NASA’s OSIRIS-REx spacecraft entered orbit around its target asteroid Bennu on Dec. 31, 2018, the OSIRIS-REx team detected multiple, bright, point sources near Bennu in the optical navigation (OpNav) images obtained by the spacecraft’s NavCam 1 imager. The science team is currently investigating the exact cause of this phenomenon, but it is probable that these images record a number of small particles near the asteroid.
The mission team’s initial analysis determined that the particles do not pose a significant risk to the spacecraft in its current orbit, which is between 1 and 1.3 miles (1.6 and 2.1 km) from Bennu. The team will continue to study the particles and their sources. After the initial detection, the team increased the cadence of OpNav observations to better study the environment around Bennu and monitor for additional occurrences.
OSIRIS-REx is scheduled to leave its current orbit on Feb. 28, when it will begin the mission’s Sample Site Selection campaign. During this next mission phase, the OSIRIS-REx spacecraft will make a series of flybys of Bennu at a distance of around 2 miles (3 km) to start mapping the asteroid in detail.
Feb 04, 2019
The spacecraft continues to orbit Bennu at an altitude ranging from 1.6 to 2.1 km. As of today, the spacecraft has been orbiting the asteroid for 32 days and is in the midst of completing its 12th orbit. It is notable that the team has been able to waive all of the weekly opportunities to trim the orbit since insertion on Dec. 31. The fact that the orbit has not needed adjustment is reflective of the flight dynamics high fidelity modeling and the excellent maneuver performance of the spacecraft.
On the ground, mission leadership has given the go-ahead to proceed to the next mission phase as scheduled. Detailed Survey: Baseball Diamond phase will commence with a small spacecraft maneuver on Feb. 28. This transition marks the end of the Navigation Campaign and the beginning of the Site Selection Campaign. The primary objective of the SSC is to globally map Bennu to identify two potential sample sites for detailed characterization.
Jan 28, 2019
The spacecraft continues in orbit around Bennu and has completed 10 orbits so far. The spacecraft takes approximately 62 hours to complete one orbit at a speed of 5 cm/sec.
On the ground, the mission team continues to map and analyze Bennu with the primary goal of selecting a site for the Touch-and-Go (TAG) sample collection event (currently scheduled for 2020). This last week, the mission held a full-project TAG Technical Interchange Meeting (TIM) to discuss the current TAG design, possible design changes due to data gathered from Bennu since Arrival, and future refinements to the TAG plan.
Jan 21, 2019
This past week, the spacecraft continued orbiting Bennu as part of the Orbital A navigation campaign, traveling around 5 cm/sec (relative to the asteroid). This phase was designed to provide the mission team with experience navigating in close proximity to a small body, and as such, there are no science requirements. The only Bennu observations being taken during Orbital A phase are optical navigation (OpNav) images using the NavCam1 camera. Orbital A continues through mid-February.
This week, the navigation team was able to officially cancel trim burn maneuvers through Feb. 9 due to the sustained performance of the spacecraft’s trajectory implemented during the Dec. 31 orbital insertion.
Jan 14, 2019
The OSIRIS-REx spacecraft continues to orbit Bennu at an altitude ranging from 1.6 to 2.1 km, with an orbital period of 61 hours. The spacecraft has completed 5.5 orbits of Bennu to date. The one-way communication time from the spacecraft back to Earth is around 5.5 minutes.
On the ground, the mission held its 14th Science Team Meeting at the University of Arizona last week. This was the first science team meeting since the spacecraft’s arrival at the asteroid, which means it was also the first gathering where the entire science team was able to work with detailed Bennu data from the spacecraft.
Jan 07, 2019
On Dec. 29 and 31, the OSIRIS-REx spacecraft successfully completed the two maneuvers required to enter orbit about Bennu. The accurate performance of these orbit insertion maneuvers, as well as the continued accurate navigation performance since orbit insertion, allowed for the wave-off of several planned updates to the spacecraft’s orbit determination (OD). The mission’s navigation team will continue to study OD performance over the first few weeks of spacecraft orbits to further refine and predict orbital operations – which will eventually allow the team to reduce the trim burn schedule.
The first orbit of Bennu, which started on Dec. 31, ended 61.4 hours later on Jan. 3. The spacecraft will continue orbiting the asteroid through mid-February.