OSIRIS-REx completes another rehearsal for Bennu touchdown

NASA has announced that its OSIRIS-REx spacecraft has completed another rehearsal before it's landing on the surface of Bennu. When the spacecraft lands on the surface of the asteroid this fall, it will collect samples to return to Earth for study. On August 11, OSIRIS-REx successfully performed its second rehearsal reaching an altitude of 131 feet over the sample site, called Nightingale, before executing a back-away burn.

The "Matchpoint" rehearsal lasted for about four hours and saw the spacecraft complete the first three of four sampling sequence maneuvers. The maneuvers included the orbit departure burn, the "Checkpoint" burn, and the Matchpoint burn. NASA says that Checkpoint is where the spacecraft autonomously checks its position and velocity before adjusting the trajectory for the third maneuver in the sequence.

Matchpoint is when the spacecraft matches the asteroid's rotation to fly in tandem with the surface directly above the sample site. After Matchpoint, the spacecraft moves to touchdown. NASA says four hours after OSIRIS-REx departed its 0.6-mile safe-home orbit, the spacecraft performed the Checkpoint maneuver at an altitude of 410 feet above Bennu's surface.

It then continued to descend for another eight minutes to perform its Matchpoint burn. OSIRIS-REx continued that trajectory for another three minutes reaching an altitude of approximately 131 feet, which is the closest it has been to the surface of the asteroid. At that point, it performed the back away burn to complete the rehearsal.

OSIRIS-REx also successfully deployed its sampling arm during the rehearsal and its Touch-And-Go Sample Acquisition Mechanism from the folded, parked position into the sample collection configuration. Spacecraft instrumentation also collected science navigation images and performed spectrometry observations of the sample site. The video above shows images captured over 13.5 minutes during the maneuvers.