NASA’she completed a key part of his mission last week by successfully blocking rocks from the surface of the potentially dangerous Bennu spacecraft. The sample was so numerous that it began to leak into space, prompting an early stow movement that the mission team reported Thursday successfully.
The spacecraft traveled over 200 million miles and four years to briefly crash into Pennu, blast it with compressed gas and collect fragments of its surface. On Oct. 21, the space agency shared the first batch of images of the bold operation, revealing an elegant yet explosive moment between rock and robot.
When the spacecraft’s robotic sampling arm, called the Touch-And-Go Sample Acquisition Mechanism, or Tagsam, touched down on Spec, it performed what constitutes a cosmic pocket move. Mission planners expected the total contact time between the arm and asteroid to be less than 16 seconds. When preliminary data was released, it showed that the contact period was only six seconds, with much of the sample collection occurring in the first three only.
The spacecraft, which operates largely independently due to the 18-minute communication delay with mission control on Earth, fired a canister of gas through Tagsam and disrupted the Determination surface and forced a sample into the arm collector’s head .
Photos taken from the head on October 22 showed that so much sample was collected that some larger rocks seemed to be unable to make it all the way inside, wedging a mylar flap meant sealing ‘ The container is partially open, allowing some small pieces of dust and pebbles to escape back out into space.
A sample of stowage was originally scheduled for Nov. 2, but instead NASA moved the multi-day procedure to Tuesday.
“The abundance of material we collected from Pennu made it possible to accelerate our retention decision,” Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, said in a statement.
Osiris-Rex tags a boulder
As the spacecraft neared and then spent two years rotating and surveying Bennu, it became clear that this small world was different from what scientists expected. The team was hoping to find several sandy surfaces that are ideal for sampling, but it turns out Bennu is a rubble pile, with rough ground covered with boulders.
About 24 hours after the operation, NASA shared the first images of the spacecraft captured missile. The Tagsam moves into position and its sampling end contacts the Bennu surface before the explosive burst of nitrogen is fired. The operation initiates tons of debris flying around the acquisition arm. It’s something really!
Although the above GIF appeared relatively fast, the operation proceeded much more delicately. The arm was lowered at about 10 centimeters per second, much slower than walking speed, when it approached the sample position.
The team aims to collect about 60 grams of dust, dirt and pebbles from Bennu’s surface. He reported on Oct. 23 that he believed Osiris-Rex had collected an adequate sample and moved to begin stuffing it quickly, omitting a planned sample mass measurement and canceling brake burn to keep the spacecraft’s acceleration as low as possible.
“We’re working to keep up with our own success here, and my job is to return as large a sample as possible from Pennu,” Lauretta said.
Although the procedure to collect the sample was done independently by the spacecraft, setting up the sample is a much slower, step-by-step process, with mission control sending orders and evaluating the results before moving on to ‘ next step.
The mission joins Hayabusa from Japan andin the asteroid exploration anodes. Hayabusa sampled and returned a very small piece of material from Itokawa’s asteroid, and Hayabusa2 is in the process of returning a substantial sample of space rock Ryugu.
With the sample now stowed on Osiris-Rex, the team will begin preparing for a long trip back to Earth, with a planned landing in the Utah desert in September 2023.