NASA has announced that its OSIRIS-REx spacecraft was able to complete its first “Checkpoint” rehearsal successfully. The successful completion of the rehearsal mission brings the spacecraft one step closer to touching down on the asteroid called Bennu. The first practice run for the mission was conducted this week.
The practice mission had the spacecraft reach an approximate altitude of 246 feet over site Nightingale before executing a back-away burn to leave the asteroid. Nightingale is the primary sample collection site for the spacecraft, and is located within a crater in the northern hemisphere of the asteroid. The Checkpoint rehearsal was a four-hour-long mission that took spacecraft through the first two of the sampling sequences four maneuvers.
Those first two maneuvers were the orbit departure burn and the checkpoint burn. Checkpoint is so named because it’s the location where the spacecraft checks its position and velocity before adjusting its trajectory toward the location of the events third maneuver. The checkpoint maneuver was performed at an approximate altitude of 410 feet above Bennu’s surface. After that point, the spacecraft ascended for another nine minutes on a trajectory towards, but not reaching, the location of the third maneuver known as the “Matchpoint” burn.
When the spacecraft reached approximately 246 feet, the closest it has ever come to the surface of the asteroid, the back-away burn was performed to complete the rehearsal. During the test, the spacecraft was able to deploy its sampling arm, the Touch-And-Go Sample Acquisition Mechanism, successfully from the folded and parked position out into the sample collection configuration. Some of the instruments were also able to collect science and navigation images and made spectrum observations of the sample site, which are events that will happen during the actual sample collection.
The mission was able to confirm for the team that the OSIRIS-REx Natural Feature Tracking guidance system was able to accurately estimate the spacecraft’s position and speed relative to the asteroid as it descended towards the surface. The spacecraft is scheduled to travel to the surface of the asteroid for its sample collection attempt on August 25. Samples are expected to return to earth on September 24, 2023.