SAN ANTONIO – In a first for NASA, a U.S. mission to collect a sample of an asteroid and return it to Earth culminates on Tuesday.
NASA’s Origins, Spectral Interpretation, Resource Identification, Security - Regolith Explorer asteroid sample return mission (OSIRIS-REx) has been orbiting Bennu, an asteroid 200 million miles from Earth. The mission launched Sept. 8, 2016, and arrived to Bennu in 2018.
On Tuesday, the spacecraft will travel all the way to the asteroid’s surface during its first sample collection attempt.
During this event, OSIRIS-REx’s sampling mechanism will touch Bennu’s surface for approximately five seconds, fire a charge of pressurized nitrogen to disturb the surface and collect a sample before the spacecraft backs away. It is a complicated mission that may need a few “audibles” during the attempt, according to Jim Garvin, NASA Goddard Chief Scientist.
This series of maneuvers will bring the spacecraft down to site Nightingale, a rocky area 52 feet in diameter in Bennu’s northern hemisphere, where the spacecraft’s robotic sampling arm will attempt to collect a sample. During the sampling event, the spacecraft, which is the size of a large van, will attempt to touch down in an area that is only the size of a few parking spaces, and just a few steps away from some of these large boulders.
Analyzing the sample will help scientists understand the early solar system, as well as the hazards and resources of near-Earth space.
Asteroids are remnants of the building blocks that formed the planets and enabled life. Those like Bennu contain natural resources such as water, organics and metals. Future space exploration and economic development may rely on asteroids for these materials. The asteroid is about as tall as the Empire State Building and could potentially threaten Earth late in the next century, with a 1‐in‐2,700 chance of impacting our planet during one of its close approaches.
OSIRIS-REx is charged with collecting at least 2 oz. (60 grams) of Bennu’s rocky material to deliver back to Earth – the largest sample return from space since the Apollo program – and the mission developed two methods to verify that this sample collection occurred.
On Thursday, OSIRIS-REx’s SamCam camera will capture images of the TAGSAM head to see whether it contains Bennu’s surface material. The spacecraft will also perform a spin maneuver Thursday to determine the mass of collected material. If these measures show successful collection, the decision will be made to place the sample in the Sample Return Capsule (SRC) for return to Earth. If sufficient sample has not been collected from Nightingale, the spacecraft has onboard nitrogen charges for two more attempts. A TAG attempt at the back-up Osprey site would be made no earlier than January 2021.
The mission is expected to return to Earth on September 24, 2023. Click here to watch the event live online beginning at 4 p.m. central.