Game day
Osiris-Rex will release the sample capsule from 63,000 miles out, four hours before it’s due to touch down at the Defense Department’s Utah Test and Training Range on Sunday morning. The release command will come from spacecraft builder Lockheed Martin’s control center in Colorado. Soon afterward, the mothership will steer away and take off to explore another asteroid. The capsule — nearly 3 feet wide and 1.6 feet tall — will hit the atmosphere at 27,650 mph for the final 13 minutes of descent remaining. The main parachute will slow the last mile, allowing for a mild 11 mph touchdown. Once everything is deemed safe, the capsule will be hustled by helicopter to a makeshift clean lab at the range. The next morning, a plane will carry the sealed container full of rubble to Houston, home to NASA’s Johnson Space Center. NASA is livestreaming the touchdown, set for around 10:55 a.m. EDT.
Cleaner than clean
A new lab at Johnson will be limited to the Bennu rubble to avoid cross-contamination with other collections, said NASA curator Kevin Righter. Building 31 already holds the moon rocks brought back by the Apollo astronauts from 1969 through 1972, as well as comet dust and specks of solar wind collected during two previous missions and Mars meteorites found in Antarctica. The asteroid samples will be handled inside nitrogen-purging gloveboxes by staff in head-to-toe clean room suits. NASA plans a splashy public reveal of Bennu’s riches on Oct. 11.
Asteroid autumn
This fall is what NASA is calling Asteroid Autumn, with three asteroid missions marking major milestones. The Osiris-Rex touchdown will be followed by the launch of another asteroid hunter on Oct. 5. Both the NASA spacecraft and its target — a metal asteroid — are named Psyche. Then a month later, NASA’s Lucy spacecraft will encounter its first asteroid since soaring from Cape Canaveral, Florida, in 2021. Lucy will swoop past Dinkinesh in the main asteroid belt between Mars and Jupiter on Nov. 1. It’s a warmup for Lucy’s unprecedented tour of the so-called Trojans, swarms of asteroids that shadow Jupiter around the sun. Neither Psyche nor Lucy will collect souvenirs, nor will Osiris-Rex on its next assignment, to explore the asteroid Apophis in 2029.
Other sample returns
This is NASA’s third sample return from deep space, not counting the hundreds of pounds of moon rocks gathered by the Apollo astronauts. The agency’s first robotic sample grab ended with a bang in 2004. The capsule bearing solar wind particles slammed into the Utah desert and shattered, compromising the samples. Two years later, a U.S. capsule with comet dust landed intact. Japan’s first asteroid sample mission returned microscopic grains from asteroid Itokawa in 2010. It’s second trip yielded about 5 grams — a teaspoon or so— from the asteroid Ryugu in 2020. The Soviet Union transported moon samples to Earth during the 1970s, and China returned lunar material in 2020.