Sample neighbors

NASA and Japan's space agency, JAXA, are teaming up to exchange samples from OSIRIS-REx and Hayabusa2. Keiko Nakamura-Messenger, a research scientist for both missions, told me NASA gets 10 percent of Hayabusa2 samples and JAXA gets 0.5 percent of OSIRIS-REx samples.

NASA will store its share of both missions' samples in a renovated section of the same Johnson Space Center building where Antarctic meteorites, Stardust samples, and cosmic dust are stored. The missions will share an entrance room and anteroom, but have separate air showers and clean rooms. Design plans for the renovation include special conditions for lighting, air circulation, and paint, as well as a list of materials restricted from the room that includes Latex and magnets.

Hayabusa2 will get home first, in 2020. The spacecraft's sample capsule will land in the Australian desert, similar to the first Hayabusa mission. From there, the samples head back to JAXA's curation facility for initial analysis before being distributed to researchers around the world.

Three years later, on September 24, 2023, the OSIRIS-REx return capsule will plummet back to Earth and land at the Air Force's Utah Test and Training Range west of Salt Lake City. Teams will pick up the capsule and transport it to a portable clean room, where they will extract the inner sample canister and ship it to Houston within two or three days. Like JAXA, NASA has done this type of recovery before, with Genesis in 2004 and Stardust in 2006. (Genesis notably crash-landed, breaching the sample container, but scientists still retrieved enough fragments of collectors with solar wind to complete most of the mission's primary science goals.)

The first task in the OSIRIS-REx clean room will be to open the sample container. The bulk of the sample will be trapped in the spacecraft's TAGSAM head, and TAGSAM also has sticky exterior pads that will have picked up fine-grained material upon touching the surface of Bennu. Scientists will remove the material from TAGSAM "in a controlled way," said McCubbin—meaning the process is more methodical than, say, emptying the dust from your vacuum cleaner into a trash can.

Sample processing occurs in two phases. First, OSIRIS-REx mission scientists will spend about six months curating and analyzing the samples, completing a "general description of what we really got," said Nakamura-Messenger. This process will help complete the mission's key science objective: to return and analyze a sample of Bennu's surface. During this phase some of the material will be analyzed in Houston, and some will be examined at other institutions.

By March 2024, the mission will move on to phase two of sample processing, in which NASA begins accepting study proposals from the worldwide science community to study the OSIRIS-REx samples.