NASAof OSIRIS-REx completed its final overflight of Bennu at approximately 6 a.m. EDT (4 a.m. EDT) on April 7 and is now slowly moving away from the asteroid; however, the mission team will have to wait a few more days to find out how the spacecraft changed Bennu’s surface when it grabbed a sample of the asteroid.
The OSIRIS-REx team added this overview to document the surface changes resulting from the Touch and Go (TAG) sampling maneuver on October 20, 2020. “By monitoring the distribution of excavated material around the TAG site, we will learn more about the nature of surface and subterranean materials as well as the mechanical properties of the asteroid, ”said Dr. Dante Lauretta, Principal Investigator for OSIRIS-REx at the University of Arizona.
During the flyby, OSIRIS-REx photographed Bennu for 5.9 hours, covering more than a full rotation of the asteroid. It flew within 3.5 kilometers of Bennu’s surface – the closest since TAG sampling.
It will take at least April 13 for OSIRIS-REx to link all the data and new images of Bennu’s surface recorded during the flyby. It shares the antennas of the Deep Space Network with other missions like Mars Perseverance, and usually gets 4-6 hours of downlink time per day. “We collected around 4000 megabytes of data during the flyby,” said Mike Moreau, OSIRIS-REx deputy project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Bennu is currently about 185 million kilometers from Earth, which means we can only achieve a downlink data rate of 412 kilobits per second, so it will take several days to download all the overflight data. . “
Once the mission team receives the images and other data from the instrument, they will investigate how OSIRIS-REx scrambled Bennu’s surface. During touchdown, the spacecraft’s sampling head drove 1.6 feet (48.8 centimeters) into the asteroid’s surface and simultaneously fired a pressurized charge of nitrogen gas. The spacecraft’s thrusters lifted a large amount of surface material during the backward burn – throwing rocks and dust in the process.
OSIRIS-REx, with its pristine and precious cargo of asteroids, will remain in the vicinity of Bennu until May 10, when it will fire its thrusters and begin its two-year cruise. The mission will deliver the asteroid sample to Earth on September 24, 2023.
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering, and security and mission assurance for OSIRIS-REx (Origins Spectral Interpretation Resource Identification Security – Regolith To explore). Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona is also leading the science team and scientific observation planning and data processing for the mission. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigation in 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 Missions Directorate in Washington.