Today is the day! The OSIRIS-REx spaceship will grab the asteroid Bennu and hit him! You can watch the broadcast here while the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission attempts to launch one on Tuesday, October 20 at 6:12 p.m. EDT (5:30 p.m.) Collect sample of an asteroid. 12 p.m. CDT, 3:12 p.m. PDT).
Live coverage begins with the above feed at 5:00 p.m. EDT (4:00 p.m. CDT, 2:00 p.m. PDT) with a feed from the Mission Support Area during the TAG event.
OXIRIS-REx descends on Bennu's surface and only touches down for a few seconds with a “Touch-And-Go” or TAG maneuver. Attempts are made to capture at least 60 grams of stones and dust from the asteroid by pumping a shot of compressed nitrogen gas onto the surface, causing particles to be kicked up, which are then collected by a sampler.
The spaceship must aim at Bennu's rocky surface with great accuracy and touch down in an area only 16 m in diameter. During the maneuver, the spaceship and asteroid will be approximately 334 million km from Earth.
At this distance, the signal is delayed by 18.5 minutes to get from the spaceship to Earth. The entire sequence is therefore autonomous, with software on board that OSIRIS-REx safely navigates to the surface and, if necessary, detects it in the event of danger or boulders, it carries out a combustion to ensure the safety of the spacecraft and later attempts another sampling event.
OSIRIS-Rex is scheduled to leave Bennu in 2021 and bring the collected sample to earth on September 24, 2023.
A diagram showing the sampling maneuver of OSIRIS-REx. The maneuver is now planned for October 20, 2020. Photo credit: NASA / GSFC / UAThe nightingale crater on Bennu with the relative size of the OSIRIS-REx spacecraft. Image: NASA
The Touch-and-Go Sample Collection Mechanism (TAGSAM) has a sampling head on the end of a 3.35 m long instrument arm. OSIRIS-REx extends this arm as it approaches the asteroid, and as OSIRIS-REx slowly descends over the sampling point, the pulse carries the sampling head to the surface of the asteroid. It will only be there for about five seconds, long enough for TAGSAM to release bursts of nitrogen to stir up particles. The particles are caught by surface pads.
After taking the sample, OSIRIS-REx will slowly return from Bennu. How do we know if the maneuver was successful? The spaceship performs two separate checks.
First, the SamCam (Sampling Camera) is used to take pictures of the Sampling Head and check for the presence of material. A spin maneuver is then carried out, with which the mass of the collected sample can be determined. If there were problems, the spacecraft has enough nitrogen for two more sample attempts. If it cannot safely navigate to Nightingale, it can attempt a sampling operation at the Osprey backup site.
Further information on the mission can be found on the OSIRIS-Rex website.