NASA’s OSIRIS-REx Mission To Use Experimental X-Ray Instrument Developed by Students

NASA's OSIRIS-REx spacecraft -- the agency's first-ever asteroid sampling return mission -- has launched on Sept. 8, carrying a suite of instruments that will help study an asteroid's surface.

One of the mission's instruments is REXIS (Regolith X-ray Imaging Spectrometer), which was designed and built by 50 students from the Massachusetts Institute of Technology (MIT), together with other students and researchers from the Harvard-Smithsonian Center of Astrophysics (CfA).

Bennu, the target asteroid for the mission, emits X-rays through a process known as fluorescence, where the X-rays from the sun make the atoms on the asteroid's surface glow from specific energies, depending on the chemical component present in the material.

The spectrometer, which is the second student experiment to be sent on a NASA interplanetary mission, is tasked to study the interaction of the sun's X-rays with the asteroid soil or regolith and to identify specific chemical elements on the asteroid's surface. Moreover, REXIS will also help determine the best possible location the spacecraft's robotic arm can reach out to and collect a sample.

"REXIS can image enhanced patches of glowing elements like magnesium, silicon, or iron that are typical in chondrite-type asteroids," Branden Allen, instrument scientist, said in a statement.

The two-year journey is expected to end in 2023, when the OSIRIS-REx spacecraft drops off the capsule containing the asteroid sample into the Earth's atmosphere. MIT's REXIS team will continue to study the material using their sophisticated sample-analysis instruments.

"We are very interested to see if the elemental chemistry we 'predicted' with our X-ray measurements at Bennu proves to be correct," Richard Binzel, MIT's principal investigator for REXIS, said in a news release. "Demonstrating that a REXIS-like instrument is a reliable extension of human capability creates an enabling technology we can apply to countless new destinations."

The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security Regolith Explorer) mission launched on Sept. 8 at 7:05 PM EDT from Cape Canaveral in Florida on board a United Launch Alliance's Atlas V rocket. The spacecraft embarked on a two-year journey to reach the Bennu, a dark and potentially dangerous near-Earth asteroid.