How Is NASA Preparing for Asteroid Bennu's Return?

The OSIRIS-REx spacecraft is currently on the final leg of its journey back to Earth, with samples from asteroid Bennu.

The asteroid samples—which likely hold clues into the birth of the solar system—are due back on September 24 this year.

When it arrives, a sample capsule will parachute down into the Utah desert. It will be the first-ever U.S. mission to return an asteroid sample to Earth.

Despite the spacecraft already arriving at the asteroid, touching down, and departing, its arrival back to Earth is one of the most challenging aspects of this mission.

Rowan Curtis, a space scientist at PA Consulting and the University of Oxford, U.K., told Newsweek: "When it arrives in late September 2023, it must approach Earth at precisely the correct speed and angle, or it won't make it through Earth's atmosphere. Until then, it will make a series of carefully-calculated maneuvers to ensure it arrives to us safely. Once collected on Earth, it will be distributed to scientists worldwide for studies of its exact composition, water content, precise age, and much more. In addition to helping us understand and classify asteroids, we expect the sample to shed light on what organic material was present on the early Earth, which then became the building blocks for life."

There are many things that NASA will have to bear in mind as OSIRIS-REx makes its journey, including how to protect it from vibrations, heat, and contaminants on Earth, a NASA press release said.

So how is NASA preparing for this feat?

"Once the sample capsule touches down, our team will be racing against the clock to recover it and get it to the safety of a temporary clean room," Mike Moreau, deputy project manager at NASA's Goddard Space Flight Center in Greenbelt, Maryland, said in a press release.

Over the next six months, as the spacecraft continues its journey, the OSIRIS-REx team will focus on perfecting its procedures for receiving the sample from the desert while protecting it from contamination.

Once the sample is retrieved from the desert, it will be brought to NASA's Johnson Space Center in Houston.

Asteroid samples may already be lying on Earth. But, contaminants from Earth make it difficult to analyze them for clues into the solar system.

The purpose of the OSIRIS-REx mission was to collect pristine samples from Bennu. This makes it imperative that once the sample does arrive on Earth, it remains that way.

Other than practicing ways to avoid contamination, flight dynamics engineers at NASA and KinetX Aerospace are assessing the trajectory that will allow the mission to come close to Earth, NASA reported. Back at the Johnson Space Center, a curation team is rehearsing how they will retrieve the sample from the capsule.

A quarter of the sample will then be distributed to other OSIRIS-REx teams in different countries for analysis.

"Bennu was chosen as the target for OSIRIS-REx because it was the most compositionally interesting of all the asteroids we could safely take a sample from and because it has a high (1 in ~1800) probability of impacting Earth in the late 22nd century," Curtis said.

"Bennu is one of about 200 asteroids with proximity to Earth and the right kind of Earth-like orbit. Within that group, only 26 were the right size to make it not too dangerous to take samples from. Of those 26, Bennu, a B-type asteroid, is one of the most interesting in terms of composition. It is primitive (roughly four billion years old), carbon-rich, and represents the kind of objects that may have brought organic materials, amino acids, and volatiles such as water to Earth. It's a Goldilocks asteroid for a sample return mission."

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