Short Wave - Touch And Go: NASA Samples An Asteroid

Episode Date: November 3, 2020

A NASA spacecraft sent out to collect a sample of rock and dust from an asteroid has nabbed so much that it's created an unexpected problem. NPR science correspondent Nell Greenfieldboyce shares a cautionary tale of a scientific mission that was almost too successful. For additional info and fun links, check out the episode page.Follow Maddie and Nell on Twitter. Maddie's @maddie_sofia and Nell's @nell_sci_NPR. Email the show at [e-mail] pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Maddie Safaya here with NPR Science correspondent, Mel Greenfield Boys. Hi, Nell. Hey, Maddie. So since it is the final day for voting, which will prove to be a very stressful day, we have decided to promptly leave Earth and go to space. Well, you're not going to escape that easy because, you know, there is still voting in space. Astronauts get to vote in space.

Fine, fine, fine. Okay, that's true. That is no escape. But today, we are talking. asteroids. Specifically, an asteroid named Benu. It's more than 200 million miles away. It orbits the sun in about 1.2 Earth years. NASA sent a spacecraft to the asteroid in 2016, right? Right. So it reached the asteroid in 2018, and it's been surveying Benu, and in the last few weeks, it's been undertaking the most critical part of its mission. And let me tell you, it has been

a crazy few weeks. I have been covering the whole thing, and it's just been fascinating to watch. Okay, first things first, Nell, I know the Earth gets hit by little space rocks all the time. As a single planetary life form, how worried do we need to be about this asteroid? Well, technically it is considered to be a potentially dangerous asteroid. It's wider than the Empire State Building is tall. It's shaped sort of like a spinning top. It's all gray and bumpy. And here's what Dante Loretta, the principal scientist for the NASA mission, had to say about this whole danger thing.

Our most recent calculations suggest that it has about a one in 2,700 chance of impacting the Earth. The good news is such an impact would not occur for at least 150 years. I mean, that's not no chance, no. You know what I mean? No, it's not nothing. But, you know, scientists are aware of it. They've got plenty of time to deal with this. If it looks like it's going to become a problem. And actually, understanding more about this kind of asteroid threat is one of the reasons they've built this spacecraft and sent it out there. And my understanding is that NASA wanted to do it. more than just look at this asteroid, right?

The scientists wanted to get up close and personal. They wanted to grab some of it and bring it back to Earth. Exactly. And there are so many ways this mission could have gone wrong. The researchers spent years planning it, worrying that they wouldn't be able to nab enough of the asteroid to get a decent sample. But as it turns out, they ran into an entirely different problem instead, one that no one expected.

It was like something out of a fairy tale where some magical creature grants you a wish. and then you get your wish, but then everything goes ironically awry. Yeah, yeah. So today on the show, we bring you a cautionary tale about wanting something really, really badly, and then getting what you want, and then realizing that you got so much of this precious thing that you might just end up losing it all. I'm Maddie Safaya, and you're listening to Shortwave from NPR. Okay, now, I understand why NASA is concerned about incoming space rocks and all,

But I imagine there are lots of reasons to embark on an asteroid mission. Yeah, so asteroids are thought to be kind of like leftovers from when the solar system formed. They represent pristine samples of the building blocks that made the planets, including Earth. And because they've been left undisturbed for billions of years, scientists say, you know, having samples, like clean samples of them in the lab, could tell us more about how our solar system came to be the way it is. And, you know, that leads to how we came to be. Right. And there have been other missions to asteroids before, right? I know Japan first sent a mission to an asteroid in 2003, but they didn't really bring that much material back. And they're in the middle of another mission now. Right. So, yeah, there was a second mission sent by Japan Space Agency that's set to come back to Earth in December. This is the first time that NASA has had a go at it. And how that came about is kind of poignant, actually. It's a little bit of a story there. I mean, the driving force behind this NASA, asteroid mission was the scientist named Mike Drake at the University of Arizona. And Loretta,

who's now the chief scientist, worked with Drake for seven years before they finally got approval from NASA in May of 2011. But by that time, Mike Drake had actually become seriously ill with cancer. And Loretta told me he died just a few months after their mission got the green light. And it was a real blow emotionally. It's actually kind of tough to talk about it. But the last thing we said to each other was that he had faith in me and that he trusted the mission and the team in my hands and that we were going to achieve great things. Wow. I mean, that's a lot. I mean, missions in space are high pressure already, but this just adds another extra layer onto the sun. Yeah. And when the spacecraft, which is called Osiris Rex, launched, it actually had a plaque

on board that was dedicated to Mike. And, you know, it reached the asteroid, as we said, a couple of years ago and it's been going round and around. So what happened once the spacecraft finally got close to Beno? Well, when they finally got their first good look at this thing, it didn't look anything like they expected. Loretta told me that they thought the asteroid was going to be smooth, like almost like a sandy surface. And immediately I was struck by how rough and rugged and rocky the surface was.

So rugged that they had to spend like a year mapping the surface using detailed images to count and catalog individual rocks trying to find a safe spot to land for just a few seconds so that the spacecraft could grab some dirt and rocks. In the end, they decided to target a place the size of a few parking spaces, and this was in a crater that's about the size of a tennis court. Well, how big is the spacecraft? It's about the size of a 15 passenger van, so like a large van. And, you know, it was going to be a tricky maneuver because this crater has got big rocks

all around it. One of them was nicknamed Mount Doom. There's rocks inside it. I mean, seriously, I would personally have a hard time parking a van in a literal parking lot, but this is like a whole different level of complexity. Okay, so they made their first attempt at collecting a sample on October 20th. What was the scene like? Well, they were only getting like little breadcrumbs of data from the spacecraft at that time. So, you know, they didn't have video or photos. They were just sitting there at their computers at Lockheed Martin Space in Littleton, Colorado. You know, it had to be just a skeleton crew because of the pandemic, and they were all wearing masks, staring at their computers. Meanwhile, poor Dante Loretta, who had been waiting like 16 years

for this moment in his life, had to be interviewed on a live NASA webcast in like the last few critical minutes. And I was watching him and seriously feeling very sorry for this dude who had to sit there and talk to an interviewer instead of just watching in nervous peace. Anyway, they talked on on and then it was finally the moment of truth. OREX has descended below the 5 meter mark. The hazard map is go for tag. We're going in. We're going

in. We're going in. And so everyone was cheering. Is the spacecraft safely backed away after coming into contact with the surface? All right. Sampling is in progress. And, you know, it was kind of funny because at that point they knew that the spacecraft had touched the asteroid with this arm that had

a sample collecting device on it. But they didn't actually have any idea what, if anything, they had collected, much less if they had gotten what they were hoping for, which was about, you know, at least 60 grams of pebbles and dust. That's around two ounces. Now, that feels like nothing. That feels like a lot for not much, you know? Two ounces does seem like not much, you know? Like that is how much you would get in like a little bottle of like face cream or it's like a couple slices of cheese. You know, maybe it doesn't seem like a very big quantity. But if you're talking about collecting stuff in space and

bringing it back to Earth, that is really hard. And it's actually only been done a few times. Other than the moon missions that sent actual astronauts, it's not like we've been able to haul in rocks from outer space. What samples science has managed to bring home to Earth through robotic missions have been really, really tiny. Like the ones that Japan brought back from an asteroid, those were like just grains. And there was one mission that brought back about a milligram of comet dust. So like tiny, tiny amounts. Okay, okay. So you're telling me for this kind of mission, like two ounces is actually a lot. It would be the biggest extraterrestrial sample brought home since the Apollo astronaut days.

And actually, this mission, you know, 60 grams was going to be the minimum that NASA wanted. But the spacecraft was built to get up to two kilograms. That's like four and a half pounds. And the researchers were not, you know, shy about saying that they really wanted a big haul. But remember, it's complicated. You know, scooping this stuff up isn't easy because stuff can just float away. in space. So the spacecraft had to have this special circular contraption at the end of an arm that kind of pressed down into the asteroid regolith, you know, the surface with all the dust and rocks.

Sure. And then it fired this burst of nitrogen gas that blasted little rocks and dust so that they went inside the collector device, which has a flap that then, you know, was supposed to close to seal stuff in. Okay, all right, I got it. But how do they know if they got enough space rocks and stuff? They got like a scale up there? What's going on? No, there's no like indicator gauge. Their plan was that once the spacecraft had done its thing and got away safely, they could actually spin the spacecraft around in a way that would let them then estimate how much mass had been added to it. And that would let them know exactly how much they had inside. Okay, that is an objectively awesome way to weigh something. So, now, did they hit that two ounce mark? Like, what's the verdict? How much do they get? Well, here's the thing.

it looks like they got a lot, a lot. And their first indication of this is when they use the spacecraft's camera to take photos of that collection device at the end of its arm. And when they did that, what they saw was particles floating around it, like asteroid material, small rocks that were floating around outside the collection device. Okay. Outside of, I feel like, I'm, all right, no, I'm no planetary scientist, but shouldn't stuff be inside of the collection device? Right, right. But what happened was the photos showed that some rocks had actually gotten crammed inside the collector in a way that was blocking that mylarb flap from closing properly and sealing things in. So what they were seeing was that stuff they'd collected floating out of the collecting device and drifting away. And the words freak out might be a little strong here.

But, you know, Loretta said that when these images came in and mission managers saw them, there was, quote, a lot of excitement. And I was immediately concerned because this is loss of sample and sample mass. That's him speaking during a hastily arranged teleconference for reporters. He says the good news was they seemed to have grabbed plenty of asteroid stuff. Definitely evidence of hundreds of grams of material and possibly more. My big concern now is that the particles are escaping because we were almost a victim of our own success here. Honestly, Nell, in my experience, being a victim of your own success is not super common during an experiment. You know what I'm saying?

Not the usual problem. Absolutely. Right. So they immediately ripped up all of their careful plans. You know, there was going to be no spinning of the spacecraft to try to measure the mass of the collected material. They didn't want to move the spacecraft any more than necessary. They didn't want any more stuff to come out. Instead, they focused all their efforts on getting the sample collection device into its return capsule and sealing it up as soon as possible. And they did it. They finally got it in the return capsule.

Oh, my God. I feel so. I was legitimately nervous during that whole section. Okay. So the return part of this is also interesting. Like, when will the sample actually get back to Earth? When will we know what they got and how much they got? In 20, 23. So it's going to parachute down in Utah and the samples will go straight to a lab. Okay, so we've got like a long wait ahead of us. So assuming all goes well when they open up this capsule. Now, is there any chance of some like Andromana strain stuff that's going to come out and kill us all? I mean, I just feel like I got to ask. You know what I'm saying?

After this year, I got to ask. It is 2020, but you seem deeply concerned that asteroid Benu is going to do us in. I mean, I don't think anyone thinks there's any kind of alien life on this asteroid. I mean, way back when asteroids may have collided with Earth and delivered water and organics to the planet. So, you know, asteroids like this one may have contributed to making Earth a good place for life. But Benu, for all of its charms, is not a cozy place for astrobiology. You know, it's traveling through space. It's getting hit by solar and galactic radiation.

And, you know, NASA did say it followed all planetary protection protocols to prevent any contamination of Earth. So hopefully that will reassure you. Yes. Now, you have soothed my asteroid-based nerves. We're going to have you back on in 2023. to find out what they brought back. Absolutely. Assuming Earth is not struck and destroyed by some other space rock before then. Indeed, indeed.

All right, now, at Astro, my friend, we appreciate you. See you, Maddie. See ya. This episode was produced by Britt Hansen and fact-checked by Ariel Elizabeth. It was edited by Giselle Grayson. I'm Maddie Safaya. Thanks for listening to Shortwave from METI. After months of campaigning, we are finally on the cusp of knowing what happens next, in the White House and in the Hall of.

of Congress. The NPR Politics Podcast will be there with you every day with the latest results and will tell you what you need to know in these uncertain times.