NASA finally picks landing site on asteroid Bennu for OSIRIS-REx spacecraft to collect samples and return to Earth
Just recently, the mission's science team revealed that the asteroid could be active, or consistently discharging particles into space. On the spacecraft's return, Bennu samples can help scientists uncover some of its mysteries
The first asteroid sample return mission, helmed by NASA, is a step closer to meeting its goal. The mission has just zeroed in on a site, from which NASA's spacecraft, OSIRIS-REx spacecraft, will extract fine grain materials from the asteroid Bennu and return them to the Earth in 2030.
The site, dubbed Nightingale — in a crater high in Bennu's northern hemisphere — is the best spot for the OSIRIS-REx spacecraft to snag its sample, says NASA.
Images have shown that the crater is relatively smooth. The low temperatures in the region mean the surface material is well-preserved. The crater is also thought to be relatively young, so scientists expect to find pristine samples of the asteroid, giving the team insight into Bennu's history.
Benny has been under NASA's radar because it is a near-earth object (NEO) and comes very close to Earth, every 6 years comes. "These close encounters give Bennu a high probability of impacting Earth in the late 22nd Century," says NASA.
"Bennu’s size, primitive composition, and potentially hazardous orbit make it one of the most fascinating and accessible NEOs," NASA adds.
OSIRIS-REx spacecraft has been scanning the asteroid for a year now, surveying its surface for possible sample extraction sites.
Just recently, the mission's science team revealed that the asteroid could be active, or consistently discharging particles into space. On the spacecraft's return, Benn samples can help scientists uncover some of its mysteries.
Bennu competed against other candidates: Sandpiper, Osprey, Kingfisher. "After thoroughly evaluating all four candidate sites, we made our final decision based on which site has the greatest amount of fine-grained material and how easily the spacecraft can access that material while keeping the spacecraft safe," says Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona in Tucson, in a statement.
"Of the four candidates, site Nightingale best meets these criteria and, ultimately, best ensures mission success."
Even then, there are challenges. The area safe enough for the spacecraft to land on Nightingale is much smaller – approximately 16 meters in diameter, which could pose problems for landing. A building-size boulder situated on the crater's eastern rim is not making things easier either.
In case things go wrong, NASA has a backup site in place: Osprey, as the spacecraft is capable of making multiple attempts. "Bennu has challenged OSIRIS-REx with extraordinarily rugged terrain," says Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center.
"The team has adapted by employing a more accurate, though more complex, optical navigation technique to be able to get into these small areas. We will also arm OSIRIS-REx with the capability to recognize if it is on course to touch a hazard within or adjacent to the site and wave-off before that happens."