ORLANDO, Fla. – After months of consideration, the team behind the NASA spacecraft on a mission to bring back an asteroid sample to Earth has selected where on Bennu the spacecraft will swoop in and fly away with pieces of the prehistoric rock zooming through the universe.
The OSIRIS-REx spacecraft began orbiting the 510-meter-wide asteroid Bennu at the beginning of 2019 where it has been mapping the space rock to help scientists select where the spacecraft will grab some of Bennu to bring home.
The options were down to four sites up until Thursday, when the team announced it has selected a primary and backup location. OSIRIS-REx will swoop in August 2020 to collect a sample from the spot dubbed Nightingale and, in case the spacecraft is unable to make a pickup from that location, a backup spot called Osprey was also selected. The asteroid locations were all nicknamed for birds from Egyptian mythology.
University of Central Florida astrophysicists Humberto Campins and Yan Fernandez are part of the mission’s science imaging team who helped narrow down the possible locations for the spacecraft to perform its pickup, known as a tag-and-go.
[UCF’s Humberto Campins came onto the News 6 at Nine show ahead of the NASA announcement Thursday to talk about the options. Watch that full interview at the top of this story.]
Campins explained why the team selected the spot they did for the tag-and-go on an asteroid taller than the Empire State Building.
“Nightingale has the surface properties that are more likely to be loose gravel or dust, so we’re likely to pick up a better sample and more sample,” Campins said.
Nightingale is the northern-most option on Bennu. The area is set in a small crater encompassed by a larger crater 459 feet in diameter. The site contains mostly fine-grain, dark material and has the lowest reflection and surface temperature of the four sites, according to NASA.
“This one really came out on top because of the scientific value,” OSIRIS-REx principal investigator Dante Lauretta said.
The mission -- led by Lauretta, with the University of Arizona-- launched in September 2016 from Cape Canaveral atop a United Launch Alliance Atlas V rocket and spent nearly two years chasing Bennu before catching up to the near-Earth asteroid.
Much of what the science team thought about Bennu turned out to be correct, however, the asteroid has offered some “wonderful surprises,” Campins said, which made selecting a sample site more challenging.
Originally, the spacecraft was going to approach an area about 150 feet across for the pickup, however, after arriving at Bennu, the team learned there wasn’t really a flat surface on the very rocky asteroid that would allow for that kind of approach. With the new information about Bennu, the team changed its collection plan. Now, the spacecraft will autonomously make the collection, coming in close to the asteroid’s surface, making the “tag” and pulling out. The daring operation will only take about five minutes.
Campins plans to be at the University of Arizona with the rest of the team on the day it happens but when its go time, the spacecraft will automatically do what it’s supposed to, he said.
“All we can do is wait. We’ll have a five-minute delay on what’s happening,” he said. “So it’s happening now but we won’t know for five minutes.”
During the collection, Campins said the “spacecraft will be coming down, either making small corrections and doing the sampling or, if it’s too dangerous, it will wave off and we will just standby.”
Lauretta said the spacecraft can actually tell if it’s coming onto a hazardous object, like a bolder, and fire its thrusters and back off. If that happens, it might disturb the site, which is why Osprey will be the backup location.
There is more than a 90% probability the asteroid sampling goes off without any problems, Campins said, and it’s already been done before on another asteroid called Ryugu.
The Japanese Space Agency JAXA successfully collected its second sample from Ryugu this summer and the NASA and JAXA teams have been working closely to learn from their independent missions.
“My hat is off to the Japanese. They did this,” Campins said. “They did this twice. They went right down to the surface, picked up a sample, then created an artificial crater with a missile and then went and sampled in that area. So they’re bringing back two samples from two different areas in separate canisters.”
The U.S. and Japanese missions plan to exchange 10% of their samples when OSIRIS-REx drops off the Bennu sample on Earth in 2023.