How did NASA exceed expectations with asteroid Bennu?

A view of eight samples containing the final material from the asteroid Bennu. Dust and rocks were poured into trays from the top plate of the touch-operated sample acquisition mechanism (TAGSAM) head. 51.2 grams were collected from this casting, bringing the final mass of the asteroid sample to 121.6 grams. Image credit: NASA/Erika Blumenfeld and Joseph Aebersold

NASA's Osiris Rex The spacecraft delivered an unprecedented 4.29 ounces of Bennu asteroid material to Earth, exceeding its mission goals. Despite initial challenges, the sample was successfully secured for future scientific research, ensuring a legacy of international cooperation and study of the origins of the solar system.

NASA's OSIRIS-REx spacecraft delivered 4.29 ounces (121.6 grams) of material from asteroid Bennu when it returned to Earth on September 24, 2023; The largest sample of asteroids ever collected in space and more than double the mission requirements.

Exceed expectations early

The mission team needed at least 60 grams of material to achieve the mission's science objectives, an amount that had already been exceeded before the TAGSAM head was fully opened. In October 2023, processors from the Astromaterials Research and Exploration Division (ARES) at NASA's Johnson Space Center in Houston were able to collect small rocks and dust from inside the large case containing the TAGSAM head, as well as from inside TAGSAM. He heads himself through a mylar flap to the head.

OSIRIS-REx astronomy material handlers, from left, Rachel Funk, Julia Plummer, and Janatul Firdaus prepare to raise the top plate of the Touch Screened Sample Acquisition Mechanism (TAGSAM) head and pour the last bit of asteroid rock and dust into the sample trays below. Image credit: NASA/Robert Markowitz

Overcoming challenges

Disassembly of the TAGSAM head was paused in late October 2023, when the team encountered two stubborn fasteners that prevented them from completing the process to reveal the final sample inside.

After designing, producing and testing new tooling, ARES process engineers successfully removed the fasteners in January and completed disassembly of the TAGSAM head. The remaining Bennu sample was uncovered and carefully poured into wedge-shaped containers. 1.81 ounces (51.2 grams) were collected from this casting. Combined with the 2.48 ounces (70.3 grams) previously measured and additional particles collected outside the casting, the total mass of Bennu's sample is 4.29 ounces (121.6 grams).

Securing a legacy for future research

NASA will retain at least 70% of the sample at Johnson for further research by scientists around the world, including future generations.

From NASA's Johnson repository, Bennu's material will be placed in containers and distributed to researchers for study. As part of the OSIRIS-REx mission, a group of more than 200 scientists around the world will explore the properties of the regolith, including researchers from several U.S. institutions and NASA partners. JAXA (Japan Aerospace Exploration Agency), CSA (Canadian Space Agency), and more.

Later this spring, the processing team will release a catalog of OSIRIS-REx samples, making the asteroid sample available for ordering by the global scientific community.