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.
After arriving in 2018, OSIRIS-REx spent nearly two years orbiting Bennu,
mapping and studying its rugged terrain
before carrying out its primary science objective.
On October 20th, 2020.
The spacecraft ventured to a small crater in the asteroid's northern hemisphere.
It dodged jagged rocks and towering boulders and plunged its arm
into the loose surface, excavating six tons of debris
while collecting about 250 grams of material.
OSIRIS-REx stowed its bounty and closed its sample return capsule.
It bid farewell to Bennu in May 2021,
embarking on a 1.2 billion mile cruise back to Earth.
Now, two years and four months after leaving Bennu.
OSIRIS-REx is closing in on the place where its journey began
on September 24th.
The spacecraft will approach to nearly 63,000 miles from Earth.
It will power up and release its sample return capsule at 4:42 a.m.
Mountain Time.
The capsule must be jettisoned within a narrow time frame
and at just the right angle to hit its target an area of roughly
250 square miles in Utah's West Desert.
Once the capsule is away, OSIRIS-REx will fire
its thrusters to avoid colliding with Earth.
At 8:42 a.m., the capsule will streak
into the atmosphere at a blistering 27,000 miles per hour.
It will race across the western U.S.
and begin to glow with heat, allowing infrared trackers on the ground
to chart its progress as it pushes deeper into the atmosphere.
The capsule will rapidly decelerate, subjecting the Bennu samples
to a punishing 32 G’s about 2 minutes after entry.
It will slow to Mach 1.4
and deploy its drogue parachute to stabilizing its descent.
The capsule will enter special use airspace at 8:46
a.m., almost ten miles above the Department of Defense.
Utah Test and Training range.
Radar stations will lock on and track it to
within 30 feet of its landing site at 8:50 a.m..
The capsule will extract and deploy its main parachute one mile above the ground.
It will make its final descent at a leisurely 11 miles per hour,
like a marathon runner savoring a victory lap
before touching down in the desert soil at 8:55.