Orlando, Fla. — On Tuesday evening, NASA’s OSIRIS-REx spacecraft will touch down on a massive asteroid to collect samples for a one-of-a-kind mission.
The spacecraft has been orbiting asteroid Bennu since Dec. 2018 after launching atop an Atlas V rocket from Cape Canaveral Air Force Station.
A final practice run of the sampling maneuvers went smoothly last week; OSIRIS-REx hovered about 144 feet (44 meters) over a predetermined site named Nightingale.
It’s one of four sample sites selected by NASA’s team, which includes University of Central Florida Physics and Astronomy Professor Humberto Campins.
“This asteroid gave us a couple of big surprises,” Campins told WDBO. “The biggest one is that the surface is so rocky, that the smooth surfaces we expected that would make it easy to go down and sample did not exist.”
An Aug. 11 dress rehearsal took the spacecraft through three of the four complicated maneuvers: the orbit departure burn, the “Checkpoint” burn, and the “Matchpoint” burn.
“It’s a very tricky maneuver and it went extremely well,” says Campins.
The test run also produced fascinating photos taken by a camera mounted on the sampling arm.
Bennu and OSIRIS-REx are currently 179 million miles (288 million km) from Earth and it takes about 16 minutes for the spacecraft to receive radio signals to command it.
As a result, the entire rehearsal sampling is conducted autonomously.
“Once it comes close enough, it starts to make decisions on its own on the best path to approach the crater safely,” Campins explained.
During the main sampling event in October, OSIRIS-REx will touch Bennu’s surface for about five seconds, fire a plume of pressurized nitrogen to disturb the surface and vacuum small rocks and soil.
The spacecraft is set to return the sample to Earth on Sept. 24, 2023.
You can follow along on Tuesday at 6:12 p.m. A livestream animation will display OSIRIS-REx’s sample collection activities in real time.
This will be live on NASA TV.
Asteroids are remnants of the building blocks that formed planets and enabled life. Bennu, in particular, was selected for study thanks to its accessibility, it’s surface regolith (loose rocky material), and for its potentially hazardous orbit.
Every six years Bennu comes closer to Earth and is expected to pass within 460,000 miles (750,000 km) on Sept. 23, 2060.
Evidence of once-liquid water on the primitive asteroid was quickly discovered by OSIRIS-REx.
NASA hopes this mission will discover more organic molecules on Bennu like those that may have led to the origin of life on Earth.