NASA’s OSIRIS-REx Spacecraft Bringing Back Asteroid Sample to Earth

NASA’s Origins Spectral Interpretation Resource Identification Security – Regolith Explorer spacecraft is expected to return to Earth on Sept. 24, 2023, carrying a sample from asteroid Bennu. OSIRIS-REx was launched from Cape Canaveral Air Force Station on Sept. 8, 2016, and reached the space rock in 2018. 

The space agency views asteroids as time capsules. With a sample of Bennu, scientists could better understand the history of the solar system and the formation of chemicals responsible for “the ancestorial building blocks of life,” NASA said.

Images and data transmitted by OSIRIS-REx have provided experts with information that could help them more accurately interpret remote observations of other asteroids to deploy more effective asteroid missions in the future and develop ways to protect Earth from space rocks caused by asteroid collisions.

Dante Lauretta, a regents professor of planetary science and cosmochemistry at the University of Arizona’s Lunar and Planetary Laboratory, wrote a paper about Bennu’s physical properties and the spacecraft’s approach to the asteroid. According to the professor, early expectations about Bennu’s surface were completely wrong. Instead of finding a smooth, sandy beach as seen from Earth- and space-based telescopes, OSIRIS-REx found the asteroid littered with boulders.

The spacecraft attempted to take a sample on Oct. 20, 2020, when observers made another discovery. Mission scientists and engineers were surprised to see that OSIRIS-REx easily captured space rock materials and that Bennu could have swallowed the capsule whole if the latter had not fired its thrusters to move back.

“It turns out that the particles making up Bennu’s exterior are so loosely packed and lightly bound to each other that they act more like a fluid than a solid,” Lauretta said.

The spacecraft’s arrival on the planet will mark the end of the seven-year OSIRIS-REx mission. Its return, however, is not an easy task. According to Mike Moreau, OSIRIS-REx deputy project manager at NASA’s Goddard Space Flight Center, the spacecraft would skip off the atmosphere if it is angled too high or disintegrate in the Earth’s atmosphere if its trajectory is lower than it should be.