Scientists are exulting over the safe arrival of a canister containing about a cup's worth of asteroid rocks, collected 200 million miles away, that landed in a Utah desert after a 7-year NASA mission sent to retrieve them.
The black pebbles and dirt are older than Earth, and are undisturbed remnants of the solar system's early days of planet formation. As part of an asteroid named Bennu, these rocks traveled unsullied through space for eons.
While bits of asteroids regularly fall to our planet as meteorites, scientists want to study pristine asteroid material, stuff that's uncontaminated by our planet, to understand the early chemistry that might have contributed to the emergence of life.
That's why scientists immediately whisked the returned capsule into a nearby clean room and put it under a cloak of nitrogen gas to protect it from the Earth's atmosphere as it's transported to NASA's Johnson Space Center in Houston.
Researchers anticipate getting to open up the sealed sample canister there either late Monday or early Tuesday — something they have dreamed of for nearly two decades.
"Today capped the end of an almost 20-year adventure for me," says Dante Lauretta, a planetary scientist at the University of Arizona and the leader of NASA's OSIRIS-REx mission. "I was fortunate enough to be one of the first people to lay eyes on the capsule, and boy did we stick that landing."
He's eager to start analyzing the asteroid rock, to see what surprises it might hold.
"We think we've got a lot of sample in that science canister," says Lauretta, "and we can't wait to crack into it."
A charcoal briquette
NASA's OSIRIS-REx spacecraft launched in 2016 and in 2018 finally reached Bennu, a rubble pile of an asteroid about the size of the Empire State Building. The spacecraft tagged along with the space rock for nearly two years and in 2020 it finally dipped down and briefly touched Bennu to gather a sample.
Scientists weren't sure exactly how much rock the spacecraft collected, and knew they'd only find out if its return capsule made it home.
The $1-billion mission culminated in triumph after a nail-biting final 13 minutes on Sunday morning, when the capsule entered the atmosphere at 36 times the speed of sound and fell towards a military training range in a desert near Salt Lake City.
Mission scientists anxiously awaited the deployment of the orange-and-white parachutes that would slow its fall. Without that parachute, the capsule might have crash-landed and broken open.
Lauretta says he was in a helicopter, listening to updates from mission controllers, and mentally preparing himself for the worst if the parachute failed.
"And then we heard 'main chute detected,' and I literally broke into tears," he recalls. "That was the moment I knew we made it home."
He says he felt pride, awe, gratitude, overwhelming relief, and had to convince himself it wasn't a dream.
"It's the end of a journey and the beginning of a new one," says Lauretta, adding that the laboratory investigation ahead is his focus now.
Mission managers tracked the fall of the capsule with radar and deployed helicopters in order to retrieve it once it safely touched down in the desolate desert.
The capsule, blackened from its fiery reentry through the atmosphere, looked almost like a UFO-shaped charcoal briquette, the size of a mini-fridge.
"It looked perfect. There was no sign of any damage," says Lauretta. "It was like seeing an old friend that you hadn't seen for a long time."
He said he wanted to give it a hug. "But I knew it would be all sooty," Lauretta jokes. "It was amazing and emotional. I've been emotional all day and that was one of the key moments for me."
Researchers took environmental samples of the air and dirt around the landing site, just to ensure that if any kind of contamination did occur, they'd know what the capsule had been exposed to.
The big reveal
As part of the preparation for getting it ready to travel, workers in a clean room removed the back shell of the heat shield that covered and protected the metal science canister full of extraterrestrial rocks.
All of the hardware appeared to be in good condition, says NASA's Eileen Stansbery, adding that it looked much like it did prior to launch, before it traveled over a billion miles through space.
"It was extremely clean on the inside," says Stansbery. "It was beautiful, clean, an extraordinary experience of seeing that the spacecraft itself must have worked extraordinarily well, that all of the engineering that went in to ensure that the science canister was going to remain clean did their jobs."
After it arrives at the NASA center in Houston, the canister will be opened in a special lab designed to allow researchers to study its contents while keeping the material untainted.
The earliest samples to get analyzed will probably be bits of dust that escaped a rock collection device that is locked up inside the canister.
Then researchers will slowly and methodically take apart a collection device that's inside the canister. That's the gizmo that actually touched the surface of the asteroid and holds the rocks.
The final opening of that, revealing the biggest rocks, is expected to come in the first week of October. NASA is planning an event on October 11 in which they will show off their treasure and reveal what's been learned so far.
While Japan previously brought back small amounts of dirt from a different asteroid, the new haul is the most extraterrestrial stuff brought home since the Apollo astronauts returned with moon rocks.
NASA is currently working on another mission to return rocks from Mars, and Lauretta is already dreaming of a sample return mission from a comet.
But first, he's going to pore over the bits of an asteroid that he's devoted so much of his life to obtaining.
"I have to be patient and I'm really exercising patience," says Lauretta, who notes that he couldn't just shake the returned capsule like a kid trying to figure out what was inside a wrapped Christmas present. "We've got a busy week ahead of us."
