Space Delivery: OSIRIS-REx’s Asteroid Sample Touchdown

Here’s How the September 24 Asteroid Sample Delivery Will Work

Early morning on Sunday, September 24, the OSIRIS-RExLaunched in 2016, the Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft will help astronomers investigate how planets formed and how life began, as well as improve our understanding of near-Earth asteroids.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>OSIRIS-REx spacecraft’s sample capsule will come face-to-face with Earth’s atmosphere for the first time since the mission’s 2016 launch. On board are an estimated 8.8 ounces, or 250 grams, of rocky material collected from the surface of Bennu in 2020 – NASAEstablished in 1958, the National Aeronautics and Space Administration (NASA) is an independent agency of the United States Federal Government that succeeded the National Advisory Committee for Aeronautics (NACA). It is responsible for the civilian space program, as well as aeronautics and aerospace research. Its vision is "To discover and expand knowledge for the benefit of humanity." Its core values are "safety, integrity, teamwork, excellence, and inclusion." NASA conducts research, develops technology and launches missions to explore and study Earth, the solar system, and the universe beyond. It also works to advance the state of knowledge in a wide range of scientific fields, including Earth and space science, planetary science, astrophysics, and heliophysics, and it collaborates with private companies and international partners to achieve its goals.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>NASA’s first asteroid sample and the largest ever collected in space.

Capsule’s Descent to Earth

When it approaches Earth, the OSIRIS-REx spacecraft won’t slow down as it makes its sample drop-off. Instead, when it reaches 63,000 miles (or 102,000 kilometers) above Earth’s surface – about one-third the distance from Earth to the Moon – a message from operators on the ground will trigger the capsule’s release, and the capsule will be sent spinning toward the atmosphere below. Twenty minutes after the drop-off, the spacecraft will fire its thrusters to divert past Earth toward asteroid Apophis, where it will continue investigating our solar system under a new name: OSIRIS-APEX (OSIRIS-Apophis Explorer).

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OSIRIS-REx is NASA’s first asteroid sample return mission. It launched in September 2016 on a journey to explore a near-Earth asteroid called Bennu. The mission’s thrilling finale will take place on September 24, 2023, as a capsule containing the Bennu samples touches down in Utah’s West Desert. Credit: NASA

Meanwhile, after zooming through space for four hours, the capsule will pierce Earth’s atmosphere at 8:42 a.m. MDT (10:42 a.m. EDTEDT is an abbreviation for Eastern Daylight Time, the time zone for the eastern coast of the United States and Canada when observing daylight saving time (spring/summer). It is four hours behind Coordinated Universal Time. New York City, Washington, D.C., Boston, and the Kennedy Space Center are in the Eastern Time Zone (ET).” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>EDT), traveling about 27,650 mph (44,500 kph). At this pace, the compression of Earth’s atmosphere will produce enough energy to envelop the capsule in a superheated ball of fire. A heat shield will help to regulate the temperature inside the capsule, keeping the sample safe at a temperature similar to that of Bennu’s surface.

Capsule’s Descent to Earth

Parachutes will bring the capsule’s descent to a safe landing speed. A drogue parachute designed to provide a stable transition to subsonic speeds will deploy first, about 2 minutes after the capsule enters the atmosphere. Six minutes later – at about 1 mile (1.6 kilometers) above the desert – the main chute will unfurl, carrying the capsule the rest of the way to a 36-mile by 8.5-mile (58-kilometer by 14-kilometer) area on the military range. At touchdown, the capsule will have slowed to about 11 mph (18 kph).

Finally, just 13 minutes after entering the atmosphere, the capsule will be on Earth for the first time in seven years, awaiting the recovery team’s approach.

This graphic shows the events that happen between the time the OSIRIS-REx spacecraft releases its sample capsule to the time it lands in the Utah desert. Credit: Lockheed Martin

About 20 minutes before the capsule lands, when it is still high above the veil of Earth’s atmosphere, the recovery field team will board four helicopters and head out into the desert. The infrared glow of the capsule’s heat signature will be tracked by thermal instruments until the capsule becomes visible to optical instruments, giving the recovery team a way to trace the capsule’s Earthbound path. The goal for the recovery team is to retrieve the capsule from the ground as quickly as possible to avoid contaminating the sample with Earth’s environment.

Sample Processing and Distribution

Once located and packaged for travel, the capsule will be flown via helicopter longline to a temporary clean room on the military range, where it will undergo initial processing and disassembly in preparation for its journey by aircraft to NASA’s Johnson Space Center in Houston, where the sample will be documented, cared for, and distributed for analysis to scientists worldwide.