Jun 18, 2018
The mission team this week continued preparations for the spacecraft’s arrival at Bennu by holding series of technical interchange meetings (TIMs) focusing on asteroid proximity operations. The team also held an initial walkthrough of the Touch-and-Go (TAG) sampling sequence.
The spacecraft is now less than 7 million kilometers from Bennu and has 388 million km left to travel as it chases down the asteroid for its scheduled arrival this December.
Jun 11, 2018
This past week, OSIRIS-REx continued nominal operations en route to asteroid Bennu. The spacecraft has been in space for 640 days and is currently 56.4 million km from Earth.
On the ground, several members of the OSIRIS-REx team were recognized with 2018 NASA Agency Honor Awards:
- Peter Antreasian – Exceptional Public Service Medal
- Coralie Jackman and Devin Poland – Early Career Public Achievement Medal
- Dennis Reuter – Distinguished Service Medal
- OSIRIS-REx Earth Gravity Assist (EGA) Team – Group Achievement Award
- OCAMS Instrument Team/Bashar Rizk – Silver Achievement Medal
Jun 04, 2018
OSIRIS-REx continued nominal operations in support of Outbound Cruise Phase this week, and the spacecraft team is planning Deep Space Maneuver-2 — the last significant maneuver before Approach Phase — scheduled for June 28. The instrument teams are planning the Launch+22 month instrument checkouts, which will execute in mid-July.
The range between OSIRIS-REx and Bennu is currently 8.5 million km. Because both the spacecraft and the asteroid are orbiting the Sun, OSIRIS-REx has 417 million km left to travel before arriving at Bennu in December.
May 28, 2018
This last week the mission marked a major milestone. On May 22, the Science Operations Planning Group (SOPG) held the kickoff of the mission’s Approach Phase. The SOPG Approach Kickoff marked the official start of detailed planning for the spacecraft’s instrument operations to study Bennu, which will begin on Aug. 17. The first instrument operation being planned is the spacecraft’s first observation of Bennu, which will be taken by the PolyCam imager from a distance of approximately 2 million km.
May 21, 2018
Last week the mission team conducted a successful checkout of the spacecraft’s Medium Gain Antenna (MGA). With this test, all of the spacecraft’s antennas have now been used in flight.
OSIRIS-REx has four antennas for communicating between the spacecraft and Earth. The largest, the High Gain Antenna (HGA), has the highest data rate but has a narrow gain pattern, meaning that it must be directly pointed at Earth for successful transmission. The MGA has a larger pattern, but a lower data rate. In favorable geometries, it will be used to communicate status telemetry back to Earth during the sampling maneuver. The two Low Gain Antennas (LGAs) provide near complete coverage and very low data rate communications. The LGAs are especially useful for transmitting progress telemetry during events, such as maneuvers, when the spacecraft’s other antennas aren’t facing Earth.
May 14, 2018
On May 7 and 9, the spacecraft conducted its second Sample Mass Measurement (SMM) pirouette activity. The SMM pirouette allows the mission team to measure the mass of the collected sample once it is in the TAGSAM head. Before sample collection, the spacecraft will do a number of spin maneuvers while the sample head is still empty. After sample collection, OSIRIS-REx will back away from the asteroid surface and pirouette again. The ground team will then compare the spacecraft’s mass properties for the “empty” and “full” spins to yield a basic estimate of the collected sample’s mass. The SMM maneuver this week provided the team with calibration information for the activity.
May 07, 2018
OSIRIS-REx continued nominal operations last week. The spacecraft is currently traveling at a speed of 5.86 km/sec (21,090 km/hr) relative to Earth, and 2.19 km/sec (7,883 km/hr) relative to Bennu. It has approximately 482 million km left in its journey before it arrives at the asteroid later this December.
Apr 30, 2018
Last week was the final execution week of the Operational Readiness Test (ORT), with the mission team simultaneously supporting nine weeks of parallel planning to simulate late Approach Phase, Preliminary Survey Phase, and part of Orbital A Phase. The week concluded with the simulated uplink of execution commands to the spacecraft. This ORT proved to be an extremely valuable exercise involving the entire operations team and has provided significant experience in the various stages of mission planning, implementation, and execution that will begin in earnest with the start of asteroid operations later this year.
Apr 23, 2018
This week the mission received good news regarding the Sample Return Capsule (SRC) outgassing mitigation campaign that was implemented last fall to remove excess water from the SRC. Over the last few months, the spacecraft has been placed into various positions to expose different sides of the capsule to the Sun in order to bake the moisture out. After completing the analysis of the various maneuvers, the navigation team this week confirmed that there is no longer detection of outgassing at a level that could interfere with the spacecraft’s navigation requirements during Bennu proximity operations.
Apr 16, 2018
OSIRIS-REx continued outbound cruise operations this last week. On the ground, members of the navigation team worked through the results of a Navigation Training Exercise (NTE) test on asteroid shape modeling. The test was designed to demonstrate the team’s readiness to perform landmark optical navigation techniques during asteroid proximity operations. This means the team would be able to navigate the spacecraft using Bennu’s landmarks as a guide instead of using star fields. Landmark navigation provides more precise and timely information on the spacecraft’s location around Bennu, which improves mission safety and efficiency.