NASA's Johnson Space Center curation team members have successfully removed the two fasteners from the sampler head that had prevented the remainder of OSIRIS-REx's asteroid Bennu sample material from being accessed.

Steps now are underway to complete the disassembly of the Touch-and-Go Sample Acquisition Mechanism, or TAGSAM, head to reveal the rest of the rocks and dust delivered by NASA's first asteroid sample return mission. The mission, which launched in 2016 and spent the next seven years traveling to Bennu and imaging the asteroid before collecting the sample, returned the sample to Earth on Sept. 24.

The sample is thought to contain the leftovers from the formation of the solar system 4.5 billion years ago.

"Finally having the TAGSAM head open and full access to the returned Bennu samples is a monumental achievement that reflects the unwavering dedication and ingenuity of our team," said the mission's principal investigator, Dante Lauretta, Regents Professor at the University of Arizona Lunar and Planetary Laboratory. "This success reaffirms the significance of OSIRIS-REx and our commitment to advancing our understanding of the cosmos. We eagerly anticipate the next chapter as we share these precious samples with the global scientific community and continue our journey of discovery."

The remainder of the bulk sample will be fully visible after a few additional disassembly steps, at which point image specialists will take ultra-high-resolution pictures of the sample while it is still inside the TAGSAM head. This portion of the sample will then be removed and weighed, and the team will be able to determine the total mass of Bennu material captured by the mission.

"Our engineers and scientists have worked tirelessly behind the scenes for months to not only process the more than 70 grams of material we were able to access previously, but also design, develop and test new tools that allowed us to move past this hurdle," said Eileen Stansbery, division chief for Astromaterials Research and Exploration Science at Johnson. "The innovation and dedication of this team has been remarkable. We are all excited to see the remaining treasure OSIRIS-REx holds."

Curation processors paused disassembly of the TAGSAM head hardware in mid-October after they discovered that two of the 35 fasteners could not be removed with the tools approved for use inside the OSIRIS-REx glovebox. In response, two new multi-part tools were designed and fabricated to support further disassembly of the TAGSAM head. These tools include newly custom-fabricated bits made from a specific grade of surgical, non-magnetic stainless steel – the hardest metal approved for use in the pristine curation gloveboxes.

"In addition to the design challenge of being limited to curation-approved materials to protect the scientific value of the asteroid sample, these new tools also needed to function within the tightly confined space of the glovebox, limiting their height, weight and potential arc movement," said Nicole Lunning, OSIRIS-REx curator at Johnson. "The curation team showed impressive resilience and did incredible work to get these stubborn fasteners off the TAGSAM head so we can continue disassembly. We are overjoyed with the success."

Prior to the successful removal, the team at Johnson tested the new tools and removal procedures in a rehearsal lab. After each successful test, engineers increased the assembly torque values – or twisting force – and repeated the testing procedures until the team was confident the new tools would be able to remove the fasteners while minimizing the risk of any potential damage to the TAGSAM head or any contamination of the sample within.   

Despite not being able to fully disassemble the TAGSAM head, the curation team members had already collected 2.48 ounces, or 70.3 grams, of asteroid material from the sample hardware, surpassing the agency's goal of bringing at least 60 grams to Earth. They have fulfilled all the sample requests received from the OSIRIS-REx science team so far and have hermetically sealed some of the Bennu sample for better preservation over decades, storing some at ambient temperature conditions and others at minus-112 degrees Fahrenheit.

Meanwhile, scientists at UArizona's Kuiper-Arizona Laboratory for Astromaterials Analysis have begun analyzing some of the pristine extraterrestrial material that the mission delivered from Bennu.

Later this spring, the curation team will release a catalog of the OSIRIS-REx samples, which will be available to the global scientific community.