Early morning on Sunday, Sept. 24, the OSIRIS-REx rocket’s example case will encounter Earth’s air interestingly since the mission’s 2016 send off. The rocky material that was taken from the surface of Bennu in 2020 is estimated to weigh 8.8 ounces, or 250 grams, and it is the largest sample ever taken from space by NASA.
The OSIRIS-REx spacecraft won’t slow down as it drops off its samples as it gets closer to Earth. Instead, a message from ground operators will cause the capsule to be released and sent spinning toward the atmosphere below when it reaches 63,000 miles (or 102,000 kilometers) above Earth’s surface, which is approximately one-third the distance between Earth and the Moon. The spacecraft will fire its thrusters twenty minutes after the drop to steer away from Earth and toward the asteroid Apophis, where it will continue its research into our solar system under a new name: OSIRIS-Pinnacle (OSIRIS-Apophis Voyager).
In the mean time, in the wake of zooming through space for four hours, the case will pierce Earth’s climate at 8:42 a.m. MDT (10:42 a.m. EDT), going around 27,650 mph (44,500 kph). The capsule will be enveloped in a superheated ball of fire if the Earth’s atmosphere is compressed at this rate. The sample will remain safe at a temperature comparable to that of Bennu’s surface thanks to the assistance of a heat shield in regulating the temperature within the capsule.
The capsule will descend at a speed that is safe for landing thanks to parachutes. About two minutes after the capsule enters the atmosphere, a drogue parachute designed to provide a stable transition to subsonic speeds will deploy first. The capsule will continue its journey to a 36-mile by 8.5-mile (58-kilometer by 14-kilometer) military range area six minutes later, approximately one mile (1.6 kilometers) above the desert. The capsule will have slowed down to about 11 mph (18 kph) by the time it lands.
Finally, the capsule will reach Earth for the first time in seven years just 13 minutes after entering the atmosphere, waiting for the recovery team to arrive.
Around 20 minutes before the container lands, when it is still high over the cloak of Earth’s climate, the recuperation field group will board four helicopters and go out into the desert. Thermal instruments will follow the infrared glow of the capsule’s heat signature until optical instruments can see it, allowing the recovery team to follow the capsule’s path back to Earth. To keep the sample from being tainted by Earth’s environment, the recovery team must quickly extract the capsule from the ground.
The capsule will be transported via helicopter longline to a temporary clean room on the military range, where it will undergo initial processing and disassembly in preparation for its flight to NASA’s Johnson Space Center in Houston, where the sample will be documented, cared for, and distributed to scientists around the world for analysis.