A team of NASA scientists is in the final stages of preparing for the arrival of the first US asteroid sample — slated to land on Earth in September on OSIRIS-REx spacecraft.

OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer), the first US mission to collect a sample from an asteroid, will return to Earth on September 24 with material from asteroid Bennu. It is carrying an estimated 8.8 ounces of rocky material collected from the surface of the asteroid Bennu in 2020.

A mockup of an OSIRIS-REx sample capsule was dropped on Wednesday from an aircraft and landed at the drop zone at the Department of Defense’s Utah Test and Training Range in the desert outside Salt Lake City. This was part of the mission’s final major test prior to the arrival of the actual capsule.

“We are now mere weeks away from receiving a piece of solar system history on Earth, and this successful drop test ensures we’re ready,” said Nicola Fox, associate administrator of NASA’s Science Mission Directorate in Washington, in a statement.

“Pristine material from asteroid Bennu will help shed light on the formation of our solar system 4.5 billion years ago, and perhaps even on how life on Earth began,”Fox added.

This drop test follows a series of earlier rehearsals — capsule recovery, spacecraft engineering operations, and sample curation procedures — conducted earlier this spring and summer.

Now, with less than four weeks until the spacecraft’s arrival, the OSIRIS-REx team is nearing the end of rehearsals and ready for the actual delivery.

The asteroid sample will help researchers to learn about how our planet and solar system formed, as well as the origin of organics that may have led to life on Earth.

Travelling about 27,650 mph, OSIRIS-REx is expected to enter Earth’s atmosphere at 10:42 a.m. EDT (8:12 pm IST) on September 24.

“We are now in the final leg of this seven-year journey, and it feels very much like the last few miles of a marathon, with a confluence of emotions like pride and joy coexisting with a determined focus to complete the race well,” said Rich Burns, project manager for OSIRIS-REx at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

Once retrieved, the sample will be documented, cared for, at NASA’s Johnson Space Center in Houston, and later distributed for analysis to scientists worldwide.