E7 – From Landfills to Martian Hills
Building instruments to search for the building blocks of life in the rocks of Mars is no small feat. These gadgets must endure spaceflight, landing on the Martian surface, intense radiation, wild swings in temperature, uneven surfaces and then beam data collected millions of kilometers away back to expectant researchers on Earth.
In this episode, NASA geochemist Jennifer Stern gives an insider’s view of the ups and downs of testing and deploying one of these instruments – a mass spectrometer used on the Mars Curiosity Rover. Listen to Jennifer describe testing this instrument in some of the harshest environments on Earth, including the Atacama Desert in Chile and Svalbard, a Norwegian archipelago near North Pole. Jennifer’s path to NASA was an adventurous one that found her sampling methane in Florida landfills as a doctoral student, braving anoxic caves in Mexico, and a hazing ritual that included singing death metal songs in Norway.
This episode was produced by Josh Speiser and mixed by Kayla Surrey.
Shane Hanlon: Hi Nanci.
Nanci Bompey: Hi Shane.
Shane Hanlon: Alright, favorite space movie. Go.
Nanci Bompey: Favorite space movie?
Shane Hanlon: I know.
Nanci Bompey: Spaceballs, of course. [Laughs]
Shane Hanlon: [Laughs]I was thinking about this. I took a much different track. I went much more serious. I was thinking Interstellar. Have you seen Interstellar?
Nanci Bompey: Oh yeah, I liked Interstellar.
Shane Hanlon: I think I just really like Matthew McConaughey.
Nanci Bompey: Well, who doesn’t?
Shane Hanlon: I know. I know. Or more classic like Close Encounters?
Nanci Bompey: Oh.
Shane Hanlon: Right?
Nanci Bompey: We just saw Close Encounters. It was the 30th anniversary, and we saw it on the big screen. It has Dolby. You could feel the sound. It was so good.
Shane Hanlon: Was it all digital, or did they do the whole, the old reels and all that jazz? Or it was just amazing?
Nanci Bompey: I don’t know, but it was awesome just seeing it on the big screen, and comparing it to that one that came out recently where they talked to the aliens through music.
Shane Hanlon: Oh … It doesn’t matter. Okay.
Nanci Bompey: Whatever.
Shane Hanlon: Yeah, yeah, yeah.
Nanci Bompey: Anyway, yes.
Shane Hanlon: Cool, alright. Favorite planet.
Nanci Bompey: Favorite planet. That’s … Earth.
Shane Hanlon: Earth.
Nanci Bompey: How about you, I know you …
Shane Hanlon: Nice. I don’t have one. I’m not so, this is my confession, I’m not a big space person.
Nanci Bompey: I know.
Shane Hanlon: Yeah, so, but hopefully, hopefully we can maybe change my mind. [music] Welcome to the American Geophysical Union’s podcast about the scientists and the methods behind the science. These are the stories you won’t read in a manuscript or hear in a lecture. I’m Shane Hanlon.
Nanci Bompey: And I’m Nanci Bompey.
Shane Hanlon: This is Third Pod from the Sun. Alright. I’m not in love with space, so let’s see if we can change my mind. We going to bring in one of our producers, Josh Speiser, to tell us a little bit about what he got for us. Josh?
Josh Speiser: Hey Shane. Well, Lauren Lipuma, who is a regular producer on Third Pod from the Sun and which who you’ll probably know, she and I went to the NASA Goddard Space Center in Greenbelt, Maryland, which is just outside of Washington DC, to interview Jennifer Stern. Jennifer is a geochemist who is part of NASA’s Mars Exploration Program to search for chemical signs of life on the Red Planet.
Shane Hanlon: Great, so let’s take a listen.
Jennifer Stern: My background is actually Earth science and environmental science. I looked at fertilizer pollution in the Everglades, and tracing that with chemistry. I also looked at methane in the Tallahassee landfill.
Lauren Lipuma: What would your typical day be when you’re going to a landfill in Tallahassee?
Jennifer Stern: There were these chambers that would sit on top of the landfill. We would measure the methane that was integrated in there, coming out of them. Sometimes you needed to measure the methane that was coming out of basically where the trash meets the dirt, so you’d have to stick a long pole down there, long hollow pole, and then pull with a syringe, pull gas out of the top. That was definitely the more stinky of the experiments.
If you drive past them, sometimes they just look, I mean, they build houses on these things now. They just look like hills, but really sort of bumpy sometimes. What’s actually interesting is it’s kind of pretty. It’s like rolling, green hills. When you go to the more mature sections of the landfill, there are these hills of compost where there are actually mini watermelons growing. It’s kind of weird.
Lauren Lipuma: So weird.
Josh Speiser: Florida.
Jennifer Stern: Yeah, Florida, exactly. It’s Florida, but it’s kind of funny, because this whole idea of looking for methane on Mars, it’s like we’re looking for the same kind of thing, but what you’re looking at there is biology. That’s not so different than the idea of trying to look for methane on Mars.
Shane Hanlon: I mean, Florida can sometimes seem like another planet.
Nanci Bompey: Especially when I go down to visit my mom during the winter, and hang out with all of her and her friends, which is always fun.
Shane Hanlon: What kind of instruments does Jennifer design?
Josh Speiser: She designed a mass spectrometer. That’s part of the Curiosity rover, which identifies the kinds of particles in the sample that are scooped up by the rover.
Lauren Lipuma: How do you go about designing an instrument that’s going to be used on Mars?
Jennifer Stern: That’s definitely a tough one. It never is just one person. When I got here, this instrument was in full swing of being built and tested. It was the first time that I had ever seen anything like it, because what I did was I worked with instruments in the lab. For me, going from how a lab instrument works to how you build something to go on another planet was really amazing. The kind of way that the instrument has to perform is completely different. You care about completely different things, and so you work very closely with a whole staff of engineers and of instrument scientists, and things that you don’t have to worry about on Earth.
There’s a lot of considerations that go into it. It all starts with sort of proof of concept in the lab. A lot of times, you take a bunch of parts and cobble them together. It’s kind of messy at first. Then you develop something that maybe you can take into the field. You can take it into an environment that’s Mars-like, whether it’s because it’s really cold or really dry, or maybe what you’re looking for is very Mars-like.
Lauren Lipuma: What are those considerations for designing something to go on Mars or another planetary body versus Earth?
Jennifer Stern: The first thing you always start with is the measurement you want. You look to see how it’s done on Earth. Then you think, “Okay, well, I only have this much mass that I can put on the spacecraft, so I have a limitation in mass.” Then there’s limitations in the amount of power it can use. So you start stripping things down.
Then other things you have to worry about is, “Is it going to be sitting on the surface on freezing surface of Mars?” So you have to think about how it is going to be protected from that, and what temperatures can it operate at. There are all these things that you don’t really have to worry about on Earth, that … Even when you reduce the thing to a small mass and a low power, you still have to worry about can this thing function at extreme temperatures and with radiation and at weird atmospheres. Like Venus is basically there’s sulfuric acid in the atmosphere, so you have to design something with materials that are going to be able to withstand that environment.
Shane Hanlon: Alright, Nanci. What’s the most extreme environment you’ve been in?
Nanci Bompey: I would say July in Louisiana bayou. It was so hot. I thought I was going to die.
Shane Hanlon: I went to school in Memphis, Tennessee. It was pretty absolutely terrible. Even if it’s a bayou or Memphis, I bet Jennifer’s instruments have to hold up in more extreme conditions than that.
Lauren Lipuma: Tell us how the instrument works, what it actually does. How does it pick up samples on Mars? What is it actually doing?
Jennifer Stern: The instrument measures volatiles, so it measures gases, which means an atmosphere measurement, it basically opens a flap and ingests atmosphere. There are pumps in the body of the instrument, so it can remove the atmosphere, and it can pump down and make a vacuum, and then open a valve and measure the atmosphere.
For solid samples, it’s a little more involved. For that, the arm of the rover has to either scoop or, with a drill, drill into rock, and then take that sample, those drill tailings, and put them in the body of the rover where the instrument is.
Once that sample, that powdered sample comes in, goes into a little cup. There’s 72 or 76 cups, and they’re on a carousel. It goes in a carousel. That carousel turns and pushes the cup up into one of two ovens. The oven seals, and then you start to heat the sample. As you heat the sample, that’s when you make the gasses. The gasses come off and go to the mass spectrometer.
It’s basically the size of an old school microwave, not like a nice, newer one, but a big old microwave, which is pretty big for spaceflight hardware. Lots of stuff is really small, but we’ve got pumps in there, we’ve got lots of … Even the electronics, just everything takes up space. We take a sample maybe every few months, because we’re so power intensive.
We also take a lot of time. If the rover’s going, and the goal for that time is to actually move and get places, it’s harder to stop and then do all of the work. You have to head up the arm every time you use it. You have to get the sample. Everything is the cost, it’s a cost of time or it’s a cost of power.
Shane Hanlon: Once Jen and her team build these instruments, they don’t just blast them into space on a rocket. They’ve got to road test them, find something here on Earth that’s somewhat like Mars. Turns out that that can be a bit of a challenge.
Lauren Lipuma: First you design it in the lab. You’ve taken all these considerations. Then you take it in the field.
Jennifer Stern: We wrote a proposal to go to lakes in Greenland in the middle of winter. The instrument is an underwater mass spectrometer. It wasn’t designed here. It was designed by folks who do underwater mass spectrometry in the Gulf of Mexico to try to look for hydrocarbons and oil spills. But we want to work with them, and try to design it in a different way, so that it can look for the stuff that we care about as astrobiologists, a certain organic molecules, certain trace gases that are indicators of metabolism.
They haven’t ever used it in super cold, icy environments, so we’re working with some folks who specifically design things like drills and melt probes for different planetary surfaces. We’re going to bring those folks together, try to do some testing in their lab. They have a giant freezer where they can do some cold testing. Then bring this prototype that they put together, bring it to Greenland in the middle of winter, and go to the site, and hope everything works.
It’s never just once. Each time you go into the field, you learn something that you, maybe you forgot to bring something that you really needed. Next time you can design it differently.
Lauren Lipuma: When you were telling me that, I’m kind of reminded of that scene in Apollo 13, when they throw everything on the table, and they’re like, “Make this out of this, using only this.” That’s kind of what I’m imagining that you guys doing.
Jennifer Stern: Right, but yeah, yeah. It’s like found objects. There’s just, you got a limited time you’re there. You got to figure out how to make it work. Usually you figure something out.
Lauren Lipuma: What’s the craziest place you’ve had to go to for one of these field expeditions?
Jennifer Stern: I did some field work actually in Mexico in these caves. There are these sulfidic caves where you have to go in and you have to wear a respirator actually, because there’s hydrogen sulfide, there’s carbon monoxide. There’s all these things that you can’t breathe. We went there, we were there during a flood. To get to the place, it was an eco-resort, but this was an eco-resort in winter, so nobody was there. There was a raging river that, they took us on this little tiny rowboat across. They were fighting the current, and I was thinking, “Oh my god, oh my god. I’m going to die.” It was scary.
Earlier that day, we were supposed to drive to a volcano, but because of the flooding, roads were just, you drive on a road, and then the road wouldn’t be there. It was a place where there’s weird life. There’s these sulfidic, they’re actually called snottites. They’re these things that drip from the ceiling of the cave, looking like snot. There are also some affectionately known clusters of organism called phlegm balls as well.
Lauren Lipuma: Nice.
Jennifer Stern: It’s all this stuff is living in this completely, for us at least, toxic, poison environment, but it’s using the sulfur, it’s using weird sources of nitrogen. It’s using all of the things life needs. It’s just not getting it from the place that we get it from, which is the atmosphere. We were trying to, it’s just one of the examples of trying to see how life is creative and can use different pathways to create what it needs.
To me, one of the whole reasons I do this at all is because I grew up watching National Geographic. For me, I was just like, even though it was a crazy trip, and all sorts of weird bad things happened, I was so excited, because it was such an adventure.
Josh Speiser: While Jen hasn’t gotten to do any Mars-based fieldwork, she has ventured to some pretty cool places, including Svalbard, try and say that, a Norwegian archipelago about midway between continental Norway and the North Pole, all in the name of science, team building, and of course heavy metal.
Lauren Lipuma: What kind of fond remembrances do you have… or crazy things that happened.
Jennifer Stern: Oh yeah, right. In the AMASE Project, which was the Svalbard project, there was … Everyone who was there for the first year, there was always a hazing type of event. My first year, we had to, we were given a song by a Norwegian death metal group that we had to take and then rewrite lyrics and entertain the rest of the people who had been there more than one year. We took this song, and we put in a line about every one of the scientists, every one of the people who were there.
Then this very small group … This all took place at Ny-Ålesund, which is this sort of, it’s a very small, it’s almost a research town. It’s not a real town, but I guess they have a fan club for this particular death metal band, so they had costumes for us. They had black boots and black vests, and all sorts of metal stuff. We put black makeup on our faces, like in the Kiss kind of style. We went and we did our performance. Everybody was quite amused.
You go into the field to test, “Okay, does this thing I cobbled together, does it work to answer the question that I’m asking? Does it get the measurements that we need?” Then the question of, “Okay, can it survive at the crazy temperature swings?” is better done in a lab chamber, where that stuff is tightly controlled.
Then a whole big part of field expeditions is just getting the people together who might actually be working together on a mission, in the same room, working on the same stuff. I definitely think that having done that in Svalbard, with a number of the different teams that have instruments on Curiosity, it’s so much easier to work with people when you’ve been out in the field with them, because crazy stuff happens in the field. You stay up late. You work really hard. You drink beer. It’s different than just being at the lab and coming and going every day. You’re with people all the time. You see all different sides of people. It’s much more real than just when you come to work every day.
Shane Hanlon: Nanci, what different sides of me have you seen in our close working relationship?
Nanci Bompey: Different sides of you? Sarcastic.
Shane Hanlon: No.
Nanci Bompey: More sarcastic.
Shane Hanlon: No. Is it possible? Alright, well, so there’s the people that she’s working with, but I want to hear more about the rover. I want to hear about Curiosity.
Josh Speiser: When Curiosity was going to first employ those technologies, what was that like for you?
Jennifer Stern: In 2012 in August, the mission, everybody went to Jet Propulsion Lab, which is where the mission was being run out of, and is still run out of. All the day to day operations of moving the rover, and moving the arm, and all that stuff, it all comes, it’s all centered at JPL, but everybody from all of the different instrument teams … There’s 10 instrument teams. Everybody came there for the first 90 days, to sort of be on the mission on Mars time, which is 24 hours and 40 minutes. The days keep getting later and later and later. You keep having to shift your schedule, and sleep at weird times, and get up at weird times.
When we first landed, everyone was very excited. Then there’s a lot of checking. There’s a lot of checking if everything is still there, everything’s fine. Then they start with the most basic and simpler instruments, and do the imaging and the camera stuff. Well, we are the most power-hungry instrument. We were the last to go. We didn’t actually get our first solid sample until after the first 90 days, so a bunch of us actually stayed extra, because we wanted our exciting first time.
We did get a first measurement of atmosphere, which was exciting. The data came down at two in the morning on a Saturday, or something crazy like that. We all gathered there, and we had the bottle of champagne. It was very exciting. All the data came down. When it comes down, everybody wanted to be the first person to see that thing, or to see that molecule. People were claiming their own molecules, and that sort of thing. There’s a little bit of competition, and a little bit of like, “I want to be the first.” But it was very exciting.
Josh Speiser: I need to ask the question here that everyone has at this time. It’s the elephant in the room. Is there life on Mars or anywhere in the solar system, for that matter?
Jennifer Stern: I tend to be agnostic about whether life is on Mars or not. I’m willing to entertain the evidence. I don’t think we’re going to find it on the surface. I feel like if we’re going to find it, it’s going to be on an ocean world. I feel like it’s going to be in the oceans of Europa or Enceladus, or even Titan, which is wild, because there’s not liquid water on Titan, there’s liquid methane.
But Mars is a tough place. I’m certainly not ruling it out, but even if we go with drills, you’re only going to that one place. It’s really tough, with the sample size of one, to know whether you find it or not. Again, the question of whether life is there is different than the question of will we find it, because we’re just limited in what we can do. But my bet would be one of the ocean worlds.
Shane Hanlon: Alright, so we’re back to my hangup, though, about studying space. Why are we studying space when there’s so much on Earth that we don’t know?
Jennifer Stern: If we think about human exploration, it’s going to have some implications for advances in health science big time, in medical science, but just the idea of something the whole human race can get behind, I think that’s good. I don’t think we have a lot of that. I think space exploration, I think that’s one big reason to do it.
We have this incredible crew of people who figure out how to make the thing work, and how to deliver the instrument. Then the instrument actually works the first time you use it. It’s kind of a miracle.
Lauren Lipuma: Yeah. What is that feeling like, just-
Jennifer Stern: It’s exciting, and it gives me so much pride in the people that I work with who put this thing together. It makes me feel lucky, because the instrument’s working, and I’m the privileged person who gets to look at the data. We really depend a lot on all the people who actually put the pieces together. But it’s just, it’s sort of, it’s trippy to see something that was built on Earth work on another planet, and to see data come back, and that you’re actually, “Hey, you’re measuring something on Mars.” It’s bizarre.
Nanci Bompey: So, Shane, has this changed your feelings about space?
Shane Hanlon: I’m not … I’ll probably never be a complete convert, but yes. I definitely see the value in space research. This is some really cool stuff. A partial convert, as it were.
Nanci Bompey: Yeah, it’s so cool. I think the thing that always gets me is the kind of that how space puts everything here in perspective, you know, like the famous pale blue dot, Carl Sagan, and looking back at we’re just a little speck in this big grand thing. It makes you think about your own humanity.
Josh Speiser: Well said, Nanci. It was really cool to go and visit Jennifer at Goddard, and to see the excitement she has for the work she’s doing, and what’s coming up. I mean, this is real science, then we’re getting real data, and learning more about our big red neighbor in the sky.
Nanci Bompey: Awesome. Alright, folks. That’s all from us at Third Pod from the Sun. Thanks Josh and Lauren for bringing us this story, and of course to Jennifer for sharing her work with us.
Shane Hanlon: This podcast is also produced with help from Olivia Ambrogio and Caitlyn Camacho. Of course, thanks to Kayla Surrey for producing this episode.
Nanci Bompey: We would love to hear your thoughts on our podcast. Please rate and review us on iTunes.
Shane Hanlon: Please.
Nanci Bompey: Please. You can always find new episodes on your favorite podcasting app, or at ThirdPodFromTheSun.com.
Shane Hanlon: That’s it. Thanks, all. We’ll see you next time.
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