NASAs Asteroid hunter, Osiris Rex, made a brief and historic landing on Tuesday on the potentially dangerous asteroid Bennu, which is more than 200 million miles from Earth. On Wednesday, the space agency revealed the first pictures of the daring operation, revealing a delicate but explosive moment between rock and robot.
Osiris-Rex traveled all the way to perform a brief touch-and-go maneuver. Its main objective is to collect a sample from the surface of the asteroid and transport it back to Earth for investigation.
On Tuesday, NASA TV reported that the spacecraft's robotic sampling arm called the Touch-and-Go Sample Acquisition Mechanism (Tagsam) landed on Bennu. A cosmic pickpocketing maneuver was carried out during the brief contact. Mission planners expected a total arm-to-asteroid contact time of less than 16 seconds. When preliminary data was released on Wednesday, it was found that the contact time was only six seconds, with much of the sampling only occurring in the first three seconds.
The spaceship, which is largely autonomous due to the 18-minute communication delay with mission control on Earth, fired a gas canister through Tagsam, which disrupted the surface of Bennu and should have allowed a sample to get into the collecting head of the arm.
Osiris-Rex was designed to sit on a flat surface, but Bennu is so rocky that the team couldn't find a suitable spot. Fortunately, Osiris-Rex outperformed its design and was able to conduct its sampling on a site called Nightingale, which is only about the size of some parking lots.
Osiris-Rex marks a boulder
Around 24 hours after the operation, NASA announced the first images of the touchdown operation captured by the spaceship. The Tagsam moves into position and its sampling head touches Bennu's surface before the explosive burst of nitrogen is fired. The operation throws up a ton of debris flying around the detection arm. It really is something!
Although the above GIF appears relatively quick, the operation went much finer. The arm was lowered at about 10 centimeters per second, much slower than the walking pace when it contacted the sample site.
The team's goal is to collect about 60 grams of dust, dirt, and pebbles from the surface of Bennu. To determine if this goal has been achieved, Osiris-Rex has reached a safe distance and is now moving his arm into position to take photos of the collecting head and weigh how much mass there is in it.
There is no guarantee that Osiris-Rex collected a significant sample. As the spaceship approached and then circled and surveyed Bennu for two years, it became clear that this tiny world is not what scientists expected. The team hoped to find a number of sandy surfaces ideal for sampling, but it turned out Bennu was a heap of rubble with a rough terrain full of boulders.
Further measurements are required to confirm that the material is in the sampling head. However, if Osiris-Rex succeeds, it will join the Japanese company Hayabusa and Hayabusa-2 missions in the annals of asteroid exploration. Hayabusa has collected and returned a small piece of material from the asteroid Itokawa, and Hayabusa2 is in the process of returning a significant sample of the Ryugu space rock.
Should the mission collect a sample, a long journey back to Earth begins with a scheduled landing in the Utah desert in September 2023.
Updated October 21: To clarify how much time Osiris-Rex spent with Bennu.
