The OSIRIS-REx spacecraft has completed the final practice run before the sample collection maneuver that will take place in October. OSIRIS-REx is now in orbit around the Bennu asteroid, which is the primary focus of the mission.
In October, the spacecraft will briefly land on the asteroid with the goal to collect valuable samples from the surface. The ancient asteroid has been around for a long while, and researchers hope that collected samples could offer valuable information about the formation of the solar system.
An initial practice run was conducted on August 11 when the spacecraft descended to an altitude that is 40 meters above the designated land zone before it propelled itself back into a safe orbit at an altitude of one kilometer. During the practice run, the touch-and-go sample acquisition mechanism was extended into the working configuration.
While the probe arrived near the asteroid in December 2018, it spent a significant amount of time on the mapping of the object, as researchers were looking for an ideal landing spot that would also yield a significant amount of samples.
During the practice runs, the probe used its thrusters to get close to the surface of the asteroid. This step is followed by a Checkpoint-type burn during which the spacecraft can assess its velocity and trajectory in an autonomous manner, which facilitates the descent while also offering the opportunity to perform final corrections.
A Matchpoint-type burn comes next and allows the spacecraft to match the speed at which the asteroid spins so it can position itself above the sample site. The final step, which involves the collection of samples and firing the thrusters to return to orbit, will take place in October.
If everything goes according to plan, the spacecraft will begin its journey towards Earth, with the samples arriving in September 2023.