NASA’s OSIRIS-REx spacecraft is on its way back to Earth with a historic cargo: a sample of rocks and dust from the ancient asteroid Bennu. The spacecraft is expected to release a capsule containing the precious material over the Utah desert on September 24, 2023, marking the first time that NASA has returned an asteroid sample to Earth.
A Seven-Year Mission to Explore Bennu
OSIRIS-REx, which stands for Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer, was launched on September 8, 2016, with the goal of studying Bennu, a near-Earth asteroid that orbits the Sun every six years. Bennu is about 1,614 feet in diameter and is estimated to be at least 4.5 billion years old, making it a relic from the early days of the solar system.
The spacecraft reached Bennu in December 2018 and spent two years orbiting and mapping the asteroid’s surface. In October 2020, OSIRIS-REx performed a daring maneuver called a “Touch-And-Go”, in which it briefly touched down on Bennu and collected about 8.8 ounces of rocks and dust using a robotic arm. The spacecraft then stowed the sample in a capsule and departed from Bennu in May 2021.
A Historic Delivery of Deep Space Dust
The sample capsule will separate from the spacecraft about four hours before reaching Earth and enter the atmosphere at a speed of about 27,000 miles per hour. The capsule will deploy a parachute and land in the Utah Test and Training Range, where a recovery team will retrieve it and transport it to a temporary clean room.
The capsule will then be shipped to NASA’s Johnson Space Center in Houston, where scientists will unpack and process the sample inside glove boxes. The sample will be distributed to the OSIRIS-REx science team around the world for analysis, as well as curated for future generations of researchers. The sample is expected to provide valuable insights into the origins of the solar system and life on Earth, as it may contain organic molecules that could have been delivered to our planet by meteorites.
A New Destination for OSIRIS-REx
After delivering the sample capsule, OSIRIS-REx will not retire but continue its exploration of the solar system. The spacecraft will adjust its trajectory toward another asteroid called Apophis, which is considered a potentially hazardous object that could pose a threat to Earth in the future. OSIRIS-REx will reach Apophis in 2029 and conduct a close flyby to study its shape, size, composition, and rotation.
OSIRIS-REx is not the first mission to return an asteroid sample to Earth, as Japan’s Hayabusa spacecraft achieved that feat in 2010 by collecting material from the asteroid Itokawa. However, OSIRIS-REx is the first NASA mission to do so and has collected a much larger and more diverse sample than Hayabusa. OSIRIS-REx is also the third mission in NASA’s New Frontiers program, which aims to explore the solar system with innovative and cost-effective spacecraft.