NASA’s latest asteroid observation operation OSIRIS-REx

NASA’s OSIRIS-REx mission is set to uncover the extent of the mess it caused on the surface of asteroid Bennu during last fall’s sample collection. On April 7, the OSIRIS-REx spacecraft will have one final close encounter with Bennu as it performs a final flyby to capture images of the asteroid’s surface. While performing the flyby, the spacecraft will observe Bennu from a distance of approximately 2.3 miles (3.7 km) – the closest since collecting Touch-and-Go samples on October 20, 2020.

The OSIRIS-REx team decided to add this latest flyby after Bennu’s surface was significantly disturbed by the sampling event. 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 also mobilized a substantial amount of surface material during the recoil burn. Because Bennu’s gravity is so low, these various forces from the spacecraft had a dramatic effect on the sampling site – throwing lots of rocks in the area and a lot of dust in the process. This final overview of Bennu will provide the mission team with the opportunity to learn how the spacecraft’s contact with Bennu’s surface altered the sample site and the region around it.

The single flyby will mimic one of the observation sequences conducted during the detailed study phase of the mission in 2019. OSIRIS-REx will photograph Bennu for 5.9 hours, which is just over a period of full rotation of the mission. ‘asteroid. In that time, the spacecraft’s PolyCam imager will obtain high-resolution images of Bennu’s northern and southern hemispheres and its equatorial region. The team will then compare these new images with the previous high-resolution images of the asteroid obtained in 2019.

Most of the spacecraft’s other scientific instruments will also collect data during the flyby, including the MapCam Imager, OSIRIS-REx Thermal Emission Spectrometer (OTES), OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) and the OSIRIS-REx laser altimeter. (OLA). Exercising these instruments will give the team a chance to assess the current state of each scientific instrument aboard the spacecraft, as dust has covered the instruments during sample collection. Understanding the health of the instruments is also part of NASA’s assessment of the possibilities for extended missions after the sample is delivered to Earth.

After the Bennu flyby, it will take several days for the flyby data to be linked to Earth. Once the data is downlinked, the team will inspect the images to understand how OSIRIS-REx disturbed the asteroid’s surface material. At this point, the team will also be able to assess the performance of scientific instruments.

The spacecraft will remain near asteroid Bennu until May 10, when the mission will enter its return cruise phase and begin its two-year journey to Earth. As it approaches Earth, the spacecraft will drop the Sample Return Capsule (SRC) which contains the rocks and dust collected on Bennu. The SRC will then travel through Earth’s atmosphere and land under parachutes at the Utah Rifle and Training Range on September 24, 2023.

Once retrieved, the capsule will be transported to the conservation facilities at the agency’s Johnson Space Center in Houston, where the sample will be collected for distribution to laboratories around the world, allowing scientists to study the formation of our system. solar and Earth as a habitable planet.

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