NASA has confirmed that Osiris Rex has completed its last flight over the asteroid Bennu. The flyby completed at about 6 a.m. EST on April 7, leaving Osiris Rex slowly drifting away from the asteroid. Mission controllers have a few more days to wait before they can figure out how the spacecraft changed the surface of the asteroid after its sample collection mission.
OSIRIS-REx Team added a file Additional flight From the asteroid to document the surface changes that resulted from the Touch and Go sampling maneuver conducted on October 20, 2020. The mission observers said that surveying the distribution of excavated material around the sample collection site allows them to learn more about the nature of surface and subsurface materials along with the asteroid’s mechanical properties. .
During its last flyby, Osiris Rex photographed the asteroid for about 6 hours, covering more than one full orbit around Benno. It flew 2.1 miles from the surface, and is the closest spacecraft since the sampling event. It will be a few days before mission controllers have an idea of the condition of the landing site because it will take until at least April 13 for the spacecraft to link all new data and images.
OSIRIS-REx shares the deep space network antennas used to transmit data with other NASA missions, including the Mars Perseverance Rover. Usually OSIRIS-REx is permitted between four to six hours of downlink time per day. To date, mission controllers have received about 4,000 megabytes of data collected during the flight.
OSIRIS-REx is currently located about 185 million miles from Earth, resulting in a slow downlink data rate of 412 Kbps. The limited time available for daily downlink, and the slow rate of downlink means that it will take several days to download all data. Osiris Rex will remain near the asteroid until May 10, when its thrusters will take off, and will begin the two-year repatriation journey.