NASA’s Osiris-Rex spacecraft lands on asteroid Bennu

Four years after launching from EarthNASA’s Osiris-Rex made a brief, historic landing Tuesday on the potentially dangerous asteroid Bennu more than 200 million miles away.

The spacecraft traveled all that way to perform a brief touch-and-go maneuver with the goal of collecting a sample from the asteroid’s surface and transporting it back to Earth for study.

We won’t know until Wednesday if Osiris-Rex managed to get hold of a space science souvenir, but on Tuesday, NASA TV reported that the spacecraft’s robotic sampling arm, called the Touch-And-Go Sample Acquisition Mechanism (Tagsam) , successfully landed on Bennu. for about 15 seconds. During the brief contact, he performed what amounts to a cosmic pickpocket maneuver.

The spacecraft, operating largely autonomously due to the 18-minute communications delay with mission control on Earth, fired a gas canister through Tagsam that should have disrupted Bennu’s surface long enough. as for a sample to make its way to the collecting head of the arm. .

The goal of the team is to collect about 60 grams of dust, dirt and pebbles from the surface of Bennu. To determine if that goal has been met, in the next few hours Osiris-Rex will maneuver into a safe position and then move his arm into position to take photos of the collector’s head and weigh how much mass is inside.

There is no guarantee that Osiris-Rex collected a meaningful sample. As the spacecraft got closer and then spent two years orbiting and examining Bennu, it became clear that this little world is different from what scientists expected. The team hoped to find a series of sandy surfaces ideal for sampling, but it turns out that Bennu is a pile of rubble, with rugged terrain strewn with rocks.

Osiris-Rex was designed to land on a flat, even surface, but Bennu is so rocky that the team couldn’t find a suitable space. Fortunately, Osiris-Rex seems to be outperforming its design when it comes to precision navigation. This gave the team the confidence to test their sampling maneuver at a site called Nightingale, which is as large as a few parking spaces.

Given the landscape, there are a number of things that could have gone wrong if the Osiris-Rex cut out a rock or came in contact with an uneven surface at an odd angle, for example. If that turns out to be the case, we will find out on Wednesday and Osiris-Rex will begin preparing for a second attempt at one of the backup sites. The spacecraft is equipped with three nitrogen gas bottles, so the team should get at least two more shots for a successful sampling.

If Osiris-Rex is successful, he will join Hayabusa from Japan and Hayabusa-2 missions in the annals of asteroid exploration. Hayabusa successfully sampled and returned a small amount of material from the Itokawa asteroid and Hayabusa2 is in the process of returning a significant sample from the Ryugu space rock.

If the mission collects a sample, it will begin a long journey back to Earth, with a planned landing in the Utah desert in September 2023.