The OSIRIS-REx spacecraft seeks early storage of an asteroid sample

NASA’s OSIRIS-REx mission is set for early storage on Tuesday, October 27, of the large sample it collected last week from the surface of the asteroid Bennu to protect and return as much sample as possible.

On October 22, the OSIRIS-REx mission team received images showing the spacecraft’s harvester head overflowing with material collected from Bennu’s surface, well above the mission requirement of two ounces (60 grams), and that some of these particles appeared to be slowly escaping from the collection head, called the Touch-And-Go Sample Acquisition Mechanism (TAGSAM).

A mylar flap on the TAGSAM allows material to easily enter the collector head and must seal to close once the particles pass. However, larger rocks that did not pass completely through the flap into the TAGSAM appear to have opened this flap, allowing chunks of the sample to escape.

Because the first sample collection event was so successful, NASA’s Science Mission Directorate has given the mission team the go-ahead to speed up sample storage, originally scheduled for November 2, at the Sample Return Capsule (SRC) from the spacecraft to minimize further sample loss.

“The abundance of material we collected from Bennu made it possible to expedite our decision to save,” said Dante Lauretta, principal investigator for OSIRIS-REx at the University of Arizona, Tucson. “The team is now working around the clock to speed up storage time so that we can protect as much of this material as possible for its return to Earth.”

Unlike other spacecraft operations where OSIRIS-REx runs autonomously through a complete sequence, sample storage is done in stages and requires team involvement and supervision. The team will send preliminary commands to the spacecraft to initiate the storage sequence, and once OSIRIS-REx completes each step in sequence, the spacecraft will send telemetry and images to the team on Earth and awaits confirmation from the team to continue. with the following. He passed.

Currently it takes just over 18.5 minutes for signals to travel between Earth and the spacecraft in one direction, so each step in the sequence is estimated to take about 37 minutes of communications transit time. Throughout the process, the mission team will continually assess the wrist alignment of the TAGSAM to ensure that the harvester head is properly positioned in the SRC. A new sequence of images has also been added to the process to observe the material escaping from the collecting head and verify that no particles are hindering the stowage process. The mission anticipates that the entire storage process will take several days, at the end of which the sample will be securely sealed in the SRC for the spacecraft’s journey back to Earth.

“I am proud of the incredible work and success of the OSIRIS-REx team thus far,” said NASA Associate Administrator for Science Thomas Zurbuchen. “This mission is well positioned to return a substantial and historic sample of an asteroid to Earth, and they have been doing all the right things, on an accelerated schedule, to protect that precious cargo.”