NASA’s OSIRIS-REx spacecraft aces asteroid-sampling dress rehearsal

NASA’s OSIRIS-REx spacecraft, which is getting ready to scoop a sample of asteroid Bennu, has successfully completed a partial dress rehearsal for its historic trip to the asteroid’s surface.

OSIRIS-REx, which has been orbiting Bennu since 2018, is scheduled to attempt to swoop down to the surface to retrieve a sample of the asteroid four months from now and bring that sample back to Earth in 2023. On Tuesday (April 14), during what NASA calls a “checkpoint rehearsal,” OSIRIS-REx got closer to Bennu’s surface than ever before while practicing the sample collection process.

“This rehearsal let us verify flight system performance during the descent, particularly the autonomous update and execution of the Checkpoint burn,” Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center in Maryland, said in a statement

Video: OSIRIS-REx gets really close to asteroid Bennu in rehearsal
Related: How NASA’s asteroid sample return mission will work (infographic)

This artist’s concept shows the trajectory and configuration of NASA’s OSIRIS-REx spacecraft during the checkpoint rehearsal on April 14, 2020. (Image credit: NASA/Goddard/University of Arizona)

In its first practice run, OSIRIS-REx went through two of the four maneuvers it would perform during a real asteroid-sampling attempt: the orbit departure burn and the “checkpoint” burn. 

First, the spacecraft fired its engines to leave its 0.6-mile (1 kilometer) orbit around Bennu and descend closer to the space rock’s surface. About four hours later, when OSIRIS-REx was at an approximate altitude of 410 feet (125 meters), it performed the checkpoint burn, which sent the spacecraft in a trajectory toward the location of its third maneuver, called the “matchpoint” burn. But instead of proceeding to that third step, the spacecraft backed away after a nine-minute descent. It reached an altitude of just 246 feet (75 m) — its closest approach yet — before heading back to orbit. 

Not only did OSIRIS-REx successfully execute these two test maneuvers, but it also practiced deploying its sampling arm, known as the Touch-And-Go Sample Acquisition Mechanism, or TAGSAM. The spacecraft’s cameras and sensors also took advantage of the close approach to collect data on the sampling site, which NASA recently dubbed Nightingale. NASA plans to conduct its first sampling attempt at the Nightingale site on Aug. 25, and the spacecraft is scheduled to begin its 2.5-year journey back to Earth in March 2021.

NASA’s OSIRIS-REx spacecraft captured this series of images of asteroid Bennu on April 14, 2020, during the first rehearsal of the mission’s sample collection event. This animation shows the SamCam instrument’s field of view as the spacecraft approached and moved away from the asteroid’s surface over a 10-minute time period between the “checkpoint” burn and the “back-away” burn. The spacecraft’s sampling arm — called the Touch-And-Go Sample Acquisition Mechanism (TAGSAM) — is visible in the central part of the frame. (Image credit: NASA/Goddard/University of Arizona)

It’s worth noting that mission controllers were able to execute Tuesday’s rehearsal without any hiccups despite the fact that most NASA employees — along with much of the rest of the world — have been ordered to work from home due to the coronavirus pandemic. 

“The mission team has maximized remote work over the last month of preparations for the Checkpoint rehearsal, as part of the COVID-19 response,” NASA officials said in the statement. “On the day of rehearsal, a limited number of personnel monitored the spacecraft’s telemetry from Lockheed Martin Space’s facility, NASA’s Goddard Space Flight Center and the University of Arizona, taking appropriate safety precautions, while the rest of the team performed their roles remotely.”

“Executing this monumental milestone during this time of national crisis is a testament to the professionalism and focus of our team,” Burns added. “It speaks volumes about their ‘can-do’ attitude and hopefully will serve as a bit of good news in these challenging times.”

Email Hanneke Weitering at or follow her @hannekescience. Follow us on Twitter @Spacedotcom and on Facebook.


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