NASA OSIRIS-REx mission has one last step before asteroid touchdown

NASA has announced that its OSIRIS-REx mission has one final step to complete before it can perform its planned touchdown on asteroid Bennu. The space agency plans to perform this final step — a second rehearsal of the entire touchdown sequence — on August 11, this one similar to the Checkpoint rehearsal it performed back in April. This upcoming rehearsal has been named 'Matchpoint.'

The OSIRIS-REx mission is intended to grab a sample from the surface of rocky asteroid Bennu. The event will be called Touch-and-Go, hinting at the nature of the sample collection process: the spacecraft will perform a series of maneuvers to make contact with the asteroid, collect the bits of material, then back away from the rock and back into orbit.

NASA has spent many months evaluating Bennu, including scoping out the best place to touchdown for the sample, as well as backup locations in case the first one doesn't work out. The target location is called Nightingale, and the spacecraft will come within 131ft of the surface during the upcoming rehearsal.

Matchpoint will be the first time that OSIRIS-REx will fly in tandem with the asteroid's rotation, according to NASA, which says this will give its team the opportunity to familiarize themselves with the necessary touchdown maneuvers. As well, the team will have one last chance to verify all of the systems that will be involved in this process, including checking the navigation and imaging hardware.

Of course, the same team will analyze data after the rehearsal wraps up, as well, to determine whether the spacecraft conducted the maneuvers as intended. At the end of it all, OSIRIS-REx will return to its regular 'safe-home orbit' to wait for the upcoming Touch-and-Go event scheduled for October 20.