OSIRIS-REx asteroid probe makes final maneuver before Sept. 24 sample delivery

NASA's OSIRIS-REx probe performed one last trajectory-correcting maneuver on Sunday (Sept. 17) to set up the Sept. 24 arrival of its asteroid sample here on Earth.

OSIRIS-REx fired its thrusters briefly on Sunday, changing the probe's velocity by 7 inches (17.8 centimeters) per minute, NASA said.

"This final correction maneuver moved the sample capsule's predicted landing location east by nearly 8 miles, or 12.5 kilometers, to the center of its predetermined landing zone inside a 36-mile by 8.5-mile (58-kilometer by 14-kilometer) area on the Defense Department's Utah Test and Training Range," agency officials wrote in an update today (Sept. 19).

Sunday's engine burn was a tweak of a crucial Sept. 10 maneuver that set OSIRIS-REx on the proper course for capsule release on Sept. 24, which will take place about 63,000 miles (102,000 km) above Earth, NASA officials added. The probe is currently about 1.8 million miles (2.8 million km) from our planet, heading toward us at roughly 14,000 mph (23,000 kph).

Related: Dramatic sampling shows asteroid Bennu is nothing like scientists expected

The $1 billion OSIRIS-REx mission launched in September 2016 and headed toward Bennu, a 1,650-foot-wide (500 meters) potentially hazardous near-Earth asteroid.

OSIRIS-REx reached the space rock in December 2018, then studied it from orbit for nearly two years. On Oct. 20, 2020, the probe swooped down and snagged about 8.8 ounces (250 grams) of material from Bennu's surprisingly spongy surface.

This precious cargo is about to come to Earth inside OSIRIS-REx's return capsule, which is scheduled to touch down in Utah shortly before 11 a.m. EDT (1500 GMT) on Sunday. You can watch the action live here at Space.com, courtesy of NASA TV.

After touchdown, OSIRIS-REx's sample will make its way to NASA's Johnson Space Center (JSC) in Houston, where the material will be curated and stored. 

JSC will eventually send some of the asteroid dirt and gravel to scientists around the world, who will study it for clues about the early days of the solar system and the role that carbon-rich asteroids like Bennu may have played in life's emergence on Earth. Researchers think that such space rocks seeded our planet with organics, the carbon-containing building blocks of life, via long-ago impacts.

The main OSIRIS-REx spacecraft will keep on flying after its return capsule comes down to Earth. The probe will head toward another potentially hazardous asteroid, the notorious Apophis, on an extended mission called OSIRIS-APEX. The probe will reach Apophis in 2029.