NASA’s OSIRIS-REx Completes Last Asteroid Flyby Before Heading Home

by Ryan Whitwam

NASA’s ambitious Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) has been in orbit of the asteroid Bennu since 2018, but it’s getting ready to call it a day and head home. NASA reports that OSIRIS-REx has completed a last-minute addition to its mission profile: one final flyby of Bennu to see how its activities changed the surface of the object.

OSIRIS-REx arrived at Bennu in late 2018, but NASA spent almost two years studying the space rock before OSIRIS-REx got down to business. The spacecraft’s Touch-and-Go Sample Acquisition Mechanism (TAGSAM) allowed it to drift down and tap the asteroid, discharging a burst of compressed nitrogen. OSIRIS-REx did just that in late 2020, scooping up what could be more than two pounds of regolith. NASA would have considered the mission a success at just 2.1 ounces (60 grams).

NASA says OSIRIS-REx will depart Bennu on May 10th. The long wait is mostly thanks to orbital mechanics — if the spacecraft waits until May to leave orbit, it will use less fuel to get back to Earth. This also gave the team time to plan the now-complete final tour, which happened early on April 7th.

OSIRIS-REx spent almost six hours taking images of Bennu during the…