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."
SCOTT DETROW, HOST:
Earlier today, scientists watched nervously as an object the size of a mini fridge hurtled toward the Earth. It looked like a mini UFO, blackened and charred from its fiery descent through the atmosphere. And as it fell toward a military range in the desert outside of Salt Lake City, Utah, it deployed an orange and white striped parachute to slow its fall.
(SOUNDBITE OF ARCHIVED RECORDING)
UNIDENTIFIED PERSON: Touchdown. I repeat, (inaudible). SRC has touched down.
DETROW: This was the triumphant end of a seven-year NASA mission to collect rocks from an asteroid. NPR's Nell Greenfieldboyce is here to tell us why scientists wanted the rocks and why their safe arrival is such a big deal. Hey, Nell.
NELL GREENFIELDBOYCE, BYLINE: Hey there.
DETROW: So you've been following this mission for a while, haven't you?
GREENFIELDBOYCE: Yep. Yep. It launched back in 2016. It's called the OSIRIS-REx mission. And the spacecraft went to an asteroid called Bennu. And at the time that it grabbed some rocks from this asteroid in October of 2020, that asteroid was about 200 million miles from Earth. It's this, you know, rocky, boulder-strewn place, not that big, like, about the size of the Empire State Building. And the OSIRIS-REx spacecraft had this arm with a collection device at the end, and it just kind of touched the asteroid briefly.
DETROW: I mean, just the logistics that went into this are extraordinary and so impressive, thinking about, you know, what it takes to get that far away to such a small place, get the sample, get it back, get it here safely. All of that has to go right. But I guess the question is, why go through all this trouble and spend all this money for some rocks?
GREENFIELDBOYCE: Yeah. I mean, asteroids are space rocks, but they're also remnants of the early solar system. So scientists think they're basically, like, leftovers from when the planets were forming. And even though asteroid material falls to Earth as meteorites all the time, that stuff is contaminated with the terrestrial materials here on Earth. And what they really want is pristine samples from an asteroid that would let them study the early chemistry that was there at the very beginning and help them understand, you know, the chemistry that could have ultimately been around and helped lead to the evolution of life.
DETROW: So the capsule has made it back to Earth safely. What happens next? When do they start opening it up and actually studying these rocks?
GREENFIELDBOYCE: So the capsule gets flown to Houston tomorrow morning to NASA's Johnson Space Center. There's a lab there that's been set up with all kinds of special cabinets and things that will keep it uncontaminated while it's being studied. The idea is that they're going to open up the canister that's inside maybe late Monday, Tuesday morning. Immediately, they're going to see some dust that they're going to rush to, you know, put under microscopes and do other tests. But the real prize will be inside this collection device that's inside the canister. That's the gizmo that actually touched the asteroid that has, like, the real rocks and, like, inch-sized rocks and pebbles inside. They plan to open that the first week of October. And NASA says it's going to have this big event to reveal what's been found on October 11.
DETROW: Now, this isn't the first time that asteroid material has been brought back to Earth, right? Didn't Japan do something similar?
GREENFIELDBOYCE: Yeah, that was a different asteroid. This time there's going to be a lot more material. In fact, this is the most space stuff that's been brought back to Earth by any nation since the days of Apollo, when, you know, astronauts were bringing back big moon rocks. And so in this return capsule that landed today, they think they got about eight ounces or about a cup of asteroid stuff.
DETROW: A cup of asteroids. We'll see what that tells us. NPR's Nell Greenfieldboyce, thank you so much.
GREENFIELDBOYCE: Thank you.
(SOUNDBITE OF JAN HAMMER GROUP SONG, "DON'T YOU KNOW") Transcript provided by NPR, Copyright NPR.