On Sunday, as the OSIRIS-REx spacecraft conducts a swing-by of Earth, it carries with it an extraordinary celestial treasure: a pristine sample collected from the near-Earth asteroid Bennu.
In accordance with the mission plan, the spacecraft is set to release a capsule containing approximately 8.8 ounces of asteroid rocks and soil into Earth’s atmosphere, with the target of landing in the Utah desert.
NASA will provide a live stream of this captivating event, commencing at 10 a.m. ET on Sunday. The capsule is anticipated to enter Earth’s atmosphere at 10:42 a.m. ET, hurtling at a staggering speed of about 27,650 miles per hour (44,498 kilometers per hour). It is expected to touch down in Utah approximately 13 minutes later.
Following the release of the capsule, OSIRIS-REx will continue its cosmic journey, embarking on a mission to capture a detailed view of a different asteroid known as Apophis. The study of this sample holds immense scientific value, as it can unravel essential details about the origins of our solar system. Asteroids like Bennu are considered the “leftovers” from the early days of our solar system, providing crucial insights into the formation of celestial bodies. Moreover, studying this sample can shed light on Bennu itself, which poses a potential future collision risk with Earth.
The journey of returning NASA’s first asteroid sample collected in space to Earth has been a multi-year endeavor marked by significant milestones. Here is a retrospective of the key moments in this remarkable mission.
A Cosmic Odyssey:
The OSIRIS-REx mission, an acronym for Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, embarked on its celestial journey seven years ago when it was launched from Cape Canaveral in 2016. In December 2018, it achieved the unprecedented feat of entering orbit around the near-Earth asteroid, Bennu. This marked the first-ever US mission to a near-Earth asteroid and set several historical records.
During its mission, OSIRIS-REx performed an exceptionally close orbit of a planetary body, while Bennu became the smallest object ever orbited by a spacecraft. The spacecraft’s comprehensive survey of the asteroid provided invaluable insights, including the discovery of water ice within Bennu’s rocks and the presence of carbon linked to biology. The mission team even witnessed particles from the asteroid being released into space.
The most pivotal moment came with the historic TAG, or Touch-and-Go sample collection event, which took place on October 20, 2020. During this audacious maneuver, OSIRIS-REx’s sampling head descended 1.6 feet (0.5 meters) into the asteroid’s surface. This operation encountered an unexpected challenge when the sample collection head gathered so much material that the container couldn’t seal properly, resulting in the precious asteroid material escaping into space.
Despite these challenges, the OSIRIS-REx team displayed exceptional resilience and ingenuity, ultimately ensuring the successful collection of the largest sample ever retrieved by a NASA mission since the Apollo lunar rock missions.
The mission also included a final flyby of Bennu in April 2021, allowing the spacecraft to observe the changes in the asteroid’s surface resulting from the sample collection event. Before-and-after images revealed intriguing alterations, including the displacement of large boulders.
Return to Earth:
Since bidding farewell to Bennu in May 2021, OSIRIS-REx has been on a return trajectory to Earth, circling the sun twice to align its path with the ideal Earth approach.
Throughout this year, NASA and Lockheed Martin Space, the spacecraft’s builder and operational partner, meticulously rehearsed every step of the sample retrieval process to ensure its seamless execution.
If the spacecraft’s trajectory remains on course, the sample capsule is set to release from OSIRIS-REx approximately 63,000 miles (102,000 kilometers) from Earth early on Sunday. Following its release, the capsule will descend and land within a designated area measuring 36 miles by 8.5 miles (58 kilometers by 14 kilometers) on the Defense Department’s Utah Test and Training Range.
The capsule’s descent will be gently controlled by parachutes, ensuring a safe landing at a speed of 11 miles per hour (17.7 kilometers per hour). Dedicated recovery teams will stand by to retrieve the capsule once it is secure. A helicopter will transport the sample in a cargo net to a temporary cleanroom established at the range in June.
Subsequently, a team will prepare the sample container for transport via a C-17 aircraft to NASA’s Johnson Space Center in Houston on Monday. Details about the sample’s composition and properties will be unveiled during a NASA broadcast from Johnson on October 11.
Over the next two years, scientists will meticulously analyze the rocks and soil in a dedicated cleanroom within the Johnson Space Center. This endeavor holds immense significance as it can provide critical insights into the composition and history of our solar system.
Understanding the characteristics and trajectories of near-Earth asteroids like Bennu is vital for predicting potential collision risks with our planet and developing strategies to mitigate such threats. Moreover, these asteroid samples could hold clues about the origins of life on Earth, as they are believed to have delivered crucial elements like water during the early stages of planetary formation.
In the words of Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona in Tucson, “We’re looking for clues as to why Earth is a habitable world — this rare jewel in outer space that has oceans and has a protective atmosphere. We believe that we’re bringing back that kind of material, literally maybe representatives of the seeds of life that these asteroids delivered at the beginning of our planet that led to this amazing biosphere, biological evolution, and to us being here today.”
The OSIRIS-REx mission embodies a remarkable feat of scientific exploration, opening new frontiers in our understanding of the cosmos and the role of asteroids in shaping our solar system and our very existence.