On Sunday morning, a brown-and-white capsule will shoot through Earth’s atmosphere to drop off a cache of pristine space rock to a team of eagerly waiting scientists and engineers.
If successful, the sample return will be the end of a seven-year mission by NASA called OSIRIS-REX — which stands for Origins, Spectral Interpretation, Resources Identification and Security-Regolith Explorer — that launched in 2016. Researchers hope that the sample, taken from an asteroid named Bennu, will reveal clues about the origins of our solar system and the genesis of life on our planet.
When will OSIRIS-REX drop off the sample and how can I watch?
The sample is expected to land on Sept. 24 in a Utah desert, about 80 miles southwest of Salt Lake City, at 10:55 a.m. Eastern time. NASA will livestream the arrival on its YouTube channel starting around 10 a.m.
The OSIRIS-REX command team is scheduled earlier on Sunday to conduct a go-or-no-go poll to determine whether the spacecraft will release the capsule.
If it’s a go, the capsule will be released at 6:42 a.m. Eastern time and enter Earth’s atmosphere four hours later. A set of parachutes will inflate soon after, slowing the capsule for a gentle touchdown.
The command team will vote against the capsule drop if it sees a risk to people or property on the ground. If that happens, it plans to divert the spacecraft’s path and attempt a second sample return in 2025.
What is the purpose of the OSIRIS-REX mission?
Bennu, like other asteroids, is a geological relic of the swirling mixture of gas and dust from billions of years ago that eventually coalesced into planets. Its regolith, or loose rock and dust sitting atop the its surface, contains a memory of the origin and the evolution of our solar system. One theory among planetary scientists is that asteroids like Bennu once seeded Earth with the ingredients to form life.
But it is hard to study these concepts using pieces of asteroids that have fallen to Earth, or meteorites. Instead, many scientists turn their eyes (and their instruments) to space.
It is not the first time researchers have brought back bits of the cosmos. In 2020, a mission led by the Japanese space agency JAXA retrieved a few grams of regolith from a near-Earth asteroid named Ryugu. The OSIRIS-REX mission team anticipates about half a pound of Bennu’s unsullied asteroid dirt.
Why did the mission take so long?
OSIRIS-REX launched in 2016, embarking on a roundabout series of fuel-efficient loops through the inner solar system. It arrived at Bennu two years later.
The mission team spent two years surveying the asteroid, searching for the safest location for OSIRIS-REX to grab regolith that it could bring to Earth. In October 2020, the team used a tool that punched the surface of Bennu and then bounced off like a pogo stick.
Six months later, OSIRIS-REX began the two-year journey home.
What happens next?
Once retrieved, the capsule will be moved to a temporary clean room at the Department of Defense’s Utah Test and Training Range and then transferred to a curation facility at NASA’s Johnson Space Center in Houston. The sample team expects in October to reveal its first results to the world, including Bennu’s composition and how it compares with material brought back from other asteroids. Researchers will then spend the next two years conducting a more robust investigation of the asteroid.
The spacecraft will have a second life. It will embark on a second journey to visit Apophis, a similar near-Earth asteroid that is predicted to pass by our planet in 2029, within one-tenth of the distance to the moon. Information from the mission, named OSIRIS-APEX — where APEX means Apophis Explorer — might be useful in mitigating hazardous encounters with asteroids in the future.
