From Earth orbit to the Moon and Mars, explore the world of human spaceflight with NASA each week on the official podcast of the Johnson Space Center in Houston, Texas. Listen to in-depth conversations with the astronauts, scientists and engineers who make it possible.
On Episode 264, learn how the NanoSat Atmospheric Chemistry Hyperspectral Observation System (NACHOS) could eventually make it easier to monitor volcanic activity and air quality in cities, neighborhoods, and power plants. This episode was recorded on July 26, 2022.
Transcript
Gary Jordan (Host): Houston, we have a podcast! Welcome to the official podcast of the NASA Johnson Space Center, Episode 264, “NACHO Average Experiment.” I’m Gary Jordan, and I’ll be your host today. On this podcast we bring in the experts, scientists, engineers, and astronauts, all to let you know what’s going on in the world of human spaceflight. Today we’ll be talking about NACHOS. No, not that. It’s, unsurprisingly, an acronym, that stands for Nanosatellite Atmospheric Chemistry Hyperspectral Observation System. This instrument could make it easier to monitor volcanic activity and air quality in cities, neighborhoods, and power plants here on Earth on a much smaller scale than what’s previously been measured. NACHOS launched earlier this year on Northrop Grumman’s 17th resupply mission to the International Space Station to monitor atmospheric trace gases like sulfur dioxide and nitrogen dioxide. NACHOS has since been deployed from the International Space Station into a one-year journey in low-Earth orbit, and in fact they were able to launch another NACHOS CubeSat into orbit. So, to discuss the NACHO[S] experiment, we have NACHOS principal investigator, researcher, and task lead with the Space and Remote Sensing Group at the Department of Energy’s Los Alamos National Laboratory, Steve Love. Steve received a bachelor’s degree in physics from Washington State University, where he then went on to earn his Ph.D. in physics from Cornell University in 1991. He joined Los Alamos National Lab immediately thereafter. Since 1994 Steve has worked in the laboratory’s Space and Remote Sensing group, where his primary focus has been the development of new techniques and instrumentation for optical remote sensing and imaging spectroscopy. With that, if you’re hungry, grab a plate of nachos, and let’s talk about NACHOS. Enjoy.
[Music]
Host: Steve Love. Thanks so much for coming on Houston We Have a Podcast today.
Steve Love: Really good to be here.
Host: Hey, this is very timely that we’re talking. I know we’ve been trying to talk for a while, even ahead of when NACHOS launched to the International Space Station, but it seems, it seems like this is probably one of the better times to actually talk to you because now, when, you know, as we were talking a little bit just warming up before, before getting into the recording, you let me know that there’s actually two NACHOS in space right now, two NACHOS CubeSats. So this seems, it seems like a very exciting time. Is, is, tell me about that, you know, just where you are; is, is, you know, this, this seems to be a better time for you.
Steve Love: Yeah. So, NACHOS-1, our original NACHOS that went to the space station, it was deployed out of the Cygnus vehicle on June 28, which was I guess about three weeks ago. And then just a few days later, on July 2, our second CubeSat, which we call NACHOS-2, was launched into orbit aboard a Virgin Orbit LauncherOne vehicle. This is one of these aircraft-launched rockets. So it took off on a 747 and was dropped and was one of, NACHOS-2 was one of seven satellites that that rocket deployed. So we weren’t planning on having these go up so close together, but just, you know, the random schedule changes and stuff of these two launches, they ended up being in the same week. So yeah, it’s very exciting and very kind of hectic. You know, we got two satellites to, to babysit and, bring online. You know, where we’re at now is we’re just going through the paces of bringing the, the instrument online, getting the satellite, you know, getting control of the satellite, getting the satellite stabilized, running, you know, state of health checks. So we don’t have any real science data yet, that’ll be coming pretty soon. But right now we’re in our commissioning and checkout phase…
Host: Fantastic.
Steve Love:…on both satellites.
Host: So it’s very timely. This is great. And that’s what I wanted to get into is just what, what led us to where we are right now and then, like you said, there’s, there’s more to come. So we’ll go into, we’ll go into that a little bit more, and then we’ll explore just the science behind what you’re doing. I wanted to start though, Steve, by just talking a little bit about you because you have an interesting background in physics, and now, you’re working on this CubeSat that’s looking at the Earth. It just seems like, it seems like an interesting story arc for you. Can you tell me about, well let’s start with physics, because I’m sure, you know, physics for me, I struggled in high school with physics, that was definitely not something that I found coming easy to me. But you continued to pursue physics in your education, so it must have been something that you were quite passionate about.
Steve Love: Yeah. Well, you know, when I started college, you know, I, I knew I wanted to be some kind of scientist; I didn’t know, you know, exactly what. I was thinking chemistry. And in my chemistry classes, every time something really interesting came up, like, you know, how bonds and orbitals and stuff like that work, I’d start asking questions about that. The professor would always say, oh well, that’s actually physics. You know, after about four times of, you know, oh this, this is really cool I want to know more about that and the answer is, well, that’s actually physics, and I would say, well, maybe I better be in physics and not chemistry. And so that’s kind of what, you know, things like that are what turned me on to physics as, as a career path. And, you know, I was always interested in space and astronomy. You know, I’m of an age where I, I remember the Moon landings; I was a little kid at the time, but that was, you know, I was like nine years old when Neil Armstrong, you know, walked on the Moon, and that was just like the coolest thing for me as a little kid. And that’s sort of what really got me started. And then, and then, you know, my dad got me a telescope, you know, when I was a kid, I was always out with the telescope and stuff. So I was always interested in space and astronomy. So, you know, physics background was good for that, and as it turned out I didn’t end up going into astronomy. But…
Host: But, that physics, that physics background was just something that it seemed like was a way to pursue this, this very early interest in space, so is it true…
Steve Love: Yeah.
Host:…you were using physics as a route to get you into working in the space industry?
Steve Love: Yeah, you know, always in the back of my mind now, you know, as I moved through my graduate school career, you know, I just thought I, you know, I needed to be a bit more practical and, you know, go into something that will get me a job. So I, you know, I went into solid-state physics. You know, it’s, it’s fascinating in itself and, you know, you know, it’s certainly something that, you know, gets you into the semiconductor industry or whatever, you know. So anyway, I sort of dropped the space stuff and, you know, all I can say, condensed matter physics is fascinating, and I be, my other sort of scientific passion was light and lasers, and so, you know, my doctoral work I used laser spectroscopy to study solids. So it used, used laser and impurities in solids to probe the properties of various kind of odd materials like, like glasses and disordered semiconductors. And so that got me into, you know, using optical probes to study things.
Host: I see the parallels here, because it’s, the NACHOS, some of the instruments on board, contains some of these, some of these instruments: the, you know, a spectrometer that I think, you know, that’s really important to whatever the science is that’s being measured on NACHOS, and that seemed like sort of your entrance point, your expertise in spectroscopy and continuing to study that, eventually let you explore your passions for entering into this world of space.
Steve Love: Yeah. So, you know, I came here to Los Alamos as a postdoc. And I continued doing condensed matter physics. I did, and, you know, optical probes again, I did infrared and Raman spectroscopy of some very strange quality one-dimensional materials that were sort of related to the high temperatures of superconductors that were, you know, all the rage at that time. And, you know, when my postdoc wrapped up, you know, I needed to find a job and over in this other division at Los Alamos, where they do space stuff, you know, a job opened up: they needed somebody who had infrared expertise. And I thought, well, I’ve got that and I’m kind of ready to, you know, try something new. So I joined what is now called Space and Remote Sensing Group at Los Alamos, and that’s pretty much where I’ve spent my career. And…
Host: Fantastic. That’s, so yeah, and it’s the, it, you got to explore space and remote sensing, that’s, that’s, that’s the perfect place to do that. And, and you spent, you mentioned you spending your career there; I wonder, though, at what point in your career did this idea of these, you know, a CubeSat going into Earth and looking at these interesting aspects of Earth, I wonder when NACHOS really started coming into play?
Steve Love: OK, well, we can go back to my earlier life again as a start. You know, one thing that keeps coming back in addition to space stuff is volcanoes. So, I grew up in eastern Washington state; I was in college when Mount St. Helens erupted. So that’s one of those events that, you know, for the rest of your life you remember exactly where you were and what you were doing on that day, because we had this cloud of volcanic ash turning day into night and raining down an inch of ash on us, and you know where I was and what I was doing was I was, I was about to start studying for a physics quiz the next day, and instead ended up watching the event unfold. So I’ve always had this fascination for the volcanos. OK, so now jump forward to Los Alamos. A group of us decided we really would like to start developing remote infrared spectroscopy, and one of the things we thought would be a good test bed for some of our ideas would be to look at volcanic gases using remote infrared spectroscopy. So, and so we hooked up with some vulcanologists, and so back kind of around 2000, thereabouts, like 20 years ago, you know, a group of us carted my infrared spectros, spectrometer to volcanoes around the world and we saw some really interesting things, particularly at this volcano Popocatepetl outside of Mexico City where I actually discovered a change in the gas composition involving kind of an obscure gas, silicon tetrafluoride. When its amount suddenly started increasing, it seemed to be an indicator that an eruption was about to occur. So that was kind of a big deal. And so we did that for a few years, but, you know, Los Alamos almost isn’t really a geology laboratory, so that wasn’t something I could continue to pursue full time. But, you know, we demonstrated the value of the techniques, got some good science out of it, and it kind of left me with the, you know, fascination with volcanoes. And so, you know, around that time we were also starting to do, as a group of laboratories — Los Alamos, [Lawrence] Livermore [National Laboratory], Sandia [National Laboratories] — started looking into hyperspectral imaging for remote monitoring of chemicals. And I was fairly new at the time and, you know, as a collaboration we built an instrument, flew it on an airplane, and, you know, actually, and demonstrated this really works well. So, you know, just to back up, you know, hyperspectral imaging is imaging where every pixel of the image contains a high-resolution spectrum with hundreds of wavelength channels, so you can look at the detailed structure of the spectrum of gases and, you know, very reliably distinguish one gas from another and so, you know, every gas has its own spectral fingerprint of, you know, particular wavelengths that absorb and doesn’t absorb, and every chemical is different. And that’s the power of spectroscopy. I mean, we can, we can look at, you know, what stars are made of, you know, so that is a very powerful technique. And hyperspectral imaging, you might say, it’s imaging with every pixel being a full high-resolution spectrum. So that’s a lot of data. So at that time, that first instrument, it was huge; it was several hundred pounds, we basically, you know, flew it on an optics table, took up the whole payload day of this NASA high-altitude aircraft, the WB-57. And, you know, it kind of became clear to me at least that if this is going to be practical, if you want to, like maybe put this in space someday, we got to make it smaller. And so I started a series of instruments and inventions trying to make, mix this whole technique smaller and more portable, and so I had some earlier instruments, you know, within the back of the — in back of my mind, someday putting it on either a small drone or a small satellite. And so, I, you know, I designed some miniaturized hyperspectral imagers, and this was really before CubeSats were a thing. There were still, you know, there were smaller satellites, but CubeSats hadn’t really come into being yet back then. So but that was kind of the thrust of a lot of my work was making hyperspectral imaging more portable, less power-hungry; how do you deal with this massive block of data where, you know, hundreds of spectral channels in every pixel and then, you know, thousands and thousands of pixels — that’s a lot of data, and how do you handle that and how do you efficiently pull the information you want out of all that data?
Host: So then how, you know, that sounds very challenging, right, and that’s, that’s not that’s, that’s not a small difference in size from several hundred pounds to, you know, a very large instrumentation, to really miniaturizing it, and then, you know, eventually, we’ll get to the point where we talk about NACHOS and I mean, CubeSats are small, they’re like a loaf of bread size. They’re, they’re, they’re very small. So that’s, that’s quite, what I would, what I would characterize as an engineering feat. So I’m guessing you had, you worked, you know, with, with a lot of engineers as you were exploring ways to miniaturize some of this technology and get it small, like you’re saying, smaller and more portable. Who were some of the folks that you were working with to explore these upgrades in technology?
Steve Love: Yeah, so, engineers, optical designers, which I, I guess I count myself as one of those, and also, you know, mathematicians or mathematical physicists who, you know, work through, you know, dealing with the data in an efficient manner.
Host: Yeah. So it took a, a decent number of people to, to really put, to really put this thing together. So let me back up for a second, because a lot of the work that you were describing, Steve, was, you know, especially as we’re, as we’re leading into talking about NACHOS itself, I think there’s this, there’s this interesting collide of your physics and looking at spectroscopy and this hyperspectral technology, but there’s this other component of your fascination with volcanoes, and you mentioned some work, some early work where you were going out and actually measuring some of the gases. I wonder, just in general, high-level, really what is interesting about these gases that are coming from volcanoes that are worth going out and measuring?
Steve Love: Yeah. Well, the, the gases are, you know, one of the few things that tell you what’s going on down deep in the Earth. So, you know, when a volcano starts beginning to erupt there are gases dissolved in, in the, in the magma. And, you know, key gases are water, water vapor and carbon dioxide, but then the next most prominent one is sulfur dioxide, and then there’s HCl (hydrogen chloride) and HF (hydrogen fluoride) and, you know, these strange gases, like I mentioned, silicon tetrafluoride. Well, you know, looking at how those relative concentrations change over time can give you hints of what, you know, what’s going on, what kind of magma is, is being brought into play, how, you know, how hot it is, is it, things like that. You know, vulcanologists, the people who do this for a living, they like to go in and get as close as possible and actually, like, stick a tube in a, in a fumarole and sample the gas and, you know, look at the chemistry of, you know, everything that’s going on there, not just the rock but the gases as well. And so, that’s, you know, intrinsically kind of a dangerous thing. And so, you know, this remote spectroscopy stuff that I was doing was, you know, an attempt to be able to get this information at a safer distance, you know? So we went from vulcanologists who, you know, go and stick their face in the, in the fumarole to setting up several miles away and looking at, you know, the smoke coming out of the volcano. Depending on the volcano and what the chemistry is, it could actually give you a, you know, kind of warning of what might be coming next. And, you know, typically a volcano, when it first starts waking up, the, the first things that happen, there might be some seismic activity, but usually there’s, you know, there’s some sulfur dioxide emissions that, you know, are, are the other sign that, oh yeah, this volcano is no longer dormant, it’s starting to, you know, start emitting things.
Host: So when it comes to the gases that you’re measuring and the instruments that you were bringing out, you mentioned this idea of hyperspectral imaging and getting a really wide range of sensing the different gases and components that are coming out of volcanoes. I wonder if, is this something that you were able to bring out to different volcanoes or did you have more limited insight based on the technology that you remotely had at the time for taking these measurements?
Steve Love: Yeah. At the time, we didn’t have imagers; we had a single point spectrometer: so you point the instrument at some place, and what I would typically do is I would point it at the, you know, the gas plume, and then I would point it at some clear sky upwind of the plume, and I would, you know, compare one to the other and that way I could see the gases that were in the, in the volcanic plume. Now, while I was doing that I was really wishing that I did have some imaging, because if you want to quantify the total amount of gas coming out, you want to measure, you know, how big the plume is and how fast the wind is blowing, and, you know, kind of, it was kind of a dream at the time be able to image all that, you know, saying we could measure the wind speed by watching this puff blow in the wind and if you had the imaging capability you could quantitatively measure the total gas output, which is what the vulcanologists are really interested in. I mean, you look at the composition and you also look at the total amount: if the amount of gas is increasing, that’s also, you know, a warning that something more is probably on the way. So we didn’t have anything at the time but, you know, that’s one of the motivations for wanting to have the imaging capability.
Host: I see. OK. All right. So, so you did some work out in the field, you went to these different volcanoes. Now this opportunity, you know, as to, as you were doing this work to make this hyperspectral, these, these instruments smaller and smaller, more portable, as you say, I wonder, I wonder when the opportunity came about that you got it small enough that now it was ready for space. Let’s talk about, let’s talk about NACHOS and its inception on, like getting, getting ready to go. Tell me about some of the, the early work?
Steve Love: Yeah. So it all started about, I guess about seven years ago. There was a, effort at Los Alamos to, to build CubeSats. So they were pretty new at the time. So we had a series of CubeSats, and they were, they were, one and a half U. Now, let me back up. You know, CubeSats are a standard for very small satellites, and the basic building block is a four-inch cube, and that’s, that’s the basic unit of the CubeSat standard is a four-inch cube and that’s, that’s called a “U” for unit, I guess. And so, we had – “we” meaning Los Alamos, not me, but people in my division at Los Alamos — had developed these one and a half U CubeSats that actually put quite a few of them, like a dozen of them in orbit. And they continued developing them, and the next generation of them they decided, well, we could actually add a payload hosting capability. I mean, they had their own internal instrument, which, which is a radio frequency instrument, but they thought, well, you know, we’ve got the satellite technology for all the attitude control and, communication and telemetry and all that stuff, so we could actually host a payload. And so, the next generations they built they designed it with this sort of plug and play interface which could accommodate another one and a half U payload. So altogether you’d have a 3U CubeSat. And as you say, that, you know, a 3U CubeSat is just about the size of a loaf of bread. You know, it’s four inches by four inches by 12 inches. And so, it was basically a brainstorming session: got together with those guys, was myself and atmospheric scientist Manvendra Dubey, and Nick Dallmann, who was leading that CubeSat effort at the time, a couple of young engineers — Logan Ott is a mechanical engineer on NACHOS, he’s been there from the very beginning, and he was just a, just barely out school at the time. So just this small group of us got together and started talking about, well, what, what kind of payload should we put on one of these, and, you know, everybody looking at me — hey, Steve, could you maybe fit one of your hyperspectral imagers in a, a one and a half U, you know, package? And I thought, well, that’s a challenge, but, let me look into it, you know?
Host: Yeah.
Steve Love: And, and, you know, chatting with Dubey, the atmospheric scientist, you know, well, what do we need, you know, what kind of sensitivity, what do we look at, how good does the instrument need to be? And again, you know, as I came back going, well, that’s kind of challenging, let me see if I can do anything. So, you know, so I went back and did some preliminary designs, did some calculations of sensitivities that we could achieve and spectral resolution that we could achieve in a package that small and surprise surprise, actually, you know, just looks doable, just barely, but I think it’s doable. And so, you know, I ginned up an optical design, and actually made it and made the design fit, you know, at least on paper; actually, the optics all fits in a 1U cube. And then we reserved a half U, you know, two inches by four inches by four inches, for, for the electronics. And so we went through a series of projects. We originally went straight to NASA and proposed this, to launch a constellation of these things we’d never built, and, you know, it was just to be, you know, a little bit too ambitious and unproven at the time. So then we went to our internal funding and we, we got a fairly large internally-funded project, which we called Targeted Atmospheric Chemistry Observations from Space. And that little acronym, TACOS, that, that was Logan, mechanical engineer Logan Ott came out with that one. So our original project was called TACOS, and that was all internally funded Los Alamos money. And we went through, you know, the full design and, and prototyping of this concept, and got it to the point where, yeah, we have a working prototype that’s almost, you know, space deployable now. And that’s when we proposed to NASA Earth Science [and] Technology Office in their InVEST call, that’s the In-Space Validation of Earth Science Technologies. And if we were mature enough in our technology at that point that we know we, we won that proposal and, and, the powers that be said that, well, this is a new project and you need a new name. So, we actually put our heads together and said, OK, our first project was called TACOS, so let’s stick with the Mexican food theme, what can we come up with? [Laughter] And it was kind of, it was kind of a group effort. And we came up with NACHOS, which is NanoSat Atmospheric Chemistry Hyperspectral Observation System. It’s actually, you know, even more descriptive name than the original TACOS. So that’s exactly what it is.
Host: Oh, that’s fantastic.
Steve Love: So that’s, that’s how NACHOS came about. I don’t know what we’re going to do, you know, with the next project, if it’s going to be SALSA or ENCHILADA or what, but…
Host: I feel like the more complicated it is, you know, the, the longer the word, you know? As you’ll get to a point where you’ll be naming a, a, a, a satellite QUESADILLA; you know, have fun with that one.
Steve Love: Exactly, yeah.
Host: That’ll be interesting.
Steve Love: Yeah.
Host: Very good. OK. Awesome. Well, well, congratulations. You know, I know it seems like it was a combination of, you know, a little bit of timing and a little bit of preparation, too, your efforts into some of these other ways sort of prepared you so that when you were able to get this award for, for this Earth science part of things that you just happened to have the right maturity and the right expertise in the proposals and, and all of that where you finally got the opportunity to, to launch to space.
Steve Love: That’s right, yeah.
Host: Very good. All right. So, you got, you got it down, you got the, you got the technology down to, the size that you wanted; you started building it. Talk about the process of, once this thing was, you know, built, what you did to test it and then eventually get it integrated into Northrop Grumman Cygnus?
Steve Love: Yeah. So, you know, there’s a whole sort of standard slew of tests. You know, first we had to, you know, test the optics, you know, and, and, well actually, you know, there was quite a bit of work going from the design to reality of the spectrometer. There were some issues that came up when we were building it, like our grating was manufactured backwards. We couldn’t figure out why we weren’t getting enough light, very much light through the system at all until we realized, oh, it, the diffraction grating is sending light to the opposite direction from where it’s supposed to go. You know, a whole bunch of little problems like that. But, you know, coming up with the technique for aligning and focusing this tiny little instrument that’s, you know, the smaller you make things the smaller the adjustments you have to make, and one of the real challenges was, you know, there’s no way we’re going to be able to put motors on mirror mounts and things like that and focus this in space. We had to, you know, focus it on the ground, we had to build it rigid and robust enough that it could survive launch and stay in focus. OK. So we went through several iterations of our optics mounts, making them heftier and stiffer, and, and, you know, every time we would, you know, do a vibration take, test, so we, you know, there are, we have a vibration testing shake table that mimics the vibrations of a rocket, and you can actually program in the vibrational spectrum of a particular rocket if you want to. There’s NASA standards for, you know, how hard you have to shake it to, to imitate what an actual launch would be like. So, you know, we would design the optics, get everything aligned, shake it and find out, oh, it went out of focus; OK, we need to modify that mount; OK, let’s try it again. And finally after about three iterations, OK, we got, we got a design that works. And so then we, you know, we have the optics in place for it. And then, you know, it’s not just the optics, it’s all the electronics; everything has to survive that. So you do the vibration test, and then you have to simulate the space environment. So the other major part of the testing is thermal vacuum testing. So you put it in a vacuum chamber that you can cool down the walls of so it’s, you know, imitates the, the cold of, of space. So, yeah, we have the, the walls of the chamber cooled with liquid nitrogen, and so then you have to run, make sure your electronics all work. We had to design the optics so that it would stay in focus as the temperature changed. So, you know, our spectrometer had to be made out of all aluminum — the mirrors, the grating, you know, the, the mounts — so that when it heated up and cooled down it would all expand and contract in the same way and stay in focus. And so, we, you know, we had to run the entire satellite through the thermal vacuum testing, you know, cycle the temperature down to the lowest temperature we would expect to, to encounter and up to the highest temperature. So it would be like minus 40 degrees C up to plus, plus 40, roughly speaking; I make sure everything works and survives through all those temperatures. And, you know, and of course, doing that, you know, a few other things, like in the electronics, would break and we have to figure out why and fix it and modify it, and then finally, you, you pass all those tests, you say, OK, we’re, we’re ready. We can, we can deliver this thing to be launched.
Host: Did you get to go out to [NASA] Wallops [Flight Facility] and actually watch it?
Steve Love: I did, yes. I went out to Wallops and that was last, you know, all these years in this space technology group, this is my very first, you know, live rocket launch I ever witnessed. So that was, that was a, that was a treat. Yeah.
Host: [Laughter] A treat, because not only did you get to see a cool rocket launch, but there was something that you put a lot of, you know, a lot of work into on board the vehicle. So not, it was, you know, I feel like that’s probably more emotional than just the average, you know, rocket watcher.
Steve Love: Yeah. Well, it definitely is. Yeah. I mean, it’s, you know, it’s all these sort of mixed emotions, you know, it’s, it’s kind of like sending your kid off to college or something, right?
Host: Yeah.
Steve Love: You have this machine you’ve built, you’ve had your hands on for years, and now, it’s, you know, you’re watching it blast into the sky and you’re keeping your fingers crossed that it’s a safe journey, and you, you know, you kind, you kind of miss it. Yeah. [Laughter]
Host: Yeah. Now, you said, you know, after, after launch, we went through this at, at the beginning of our chat, is since, since it’s launched, you know, enough time has passed now that it, it launched to the International Space Station, which has a CubeSat deployer, and that first CubeSat has been deployed. And then you already mentioned that, that another one was launched as well. So now you got two NACHO[S] CubeSats in orbit. I, I feel like when we were talking about all the testing and stuff, we were talking about one, but what is the reason for that second one?
Steve Love: Well, that’s a good question, actually. So originally, the, the second one was meant to be a test unit. So it’s kind of standard practice to build a, what’s called a qualification model, and then the actual flight unit. So we’ve built two identical satellites. And, you know, the idea is the qualification model, you can put it through more rigorous testing, you know, take higher risks with it, you know, of possibly breaking it while you’re shaking it too hard. And then when you, you know, convince yourself that the qualification model works, then you run the, the flight instrument through, you know, the same set of tests, but not, you don’t quite shake it as hard or bake it as hard, and you try to be a little bit gentler with it for, because this is the real one and you already know what’s going to work because you did the qualification model. So we had the two satellites and the qualification model passed its test with flying colors. So we had a working satellite in our hands in addition to the, you know, what was originally intended to be the, the one and only flight satellite. And, when it came time for finding a launch, the, you know, we weren’t quite sure if the space station orbit would work for us or not. And we actually ended up, because it’s a rather low orbit, and we have deployable solar panels that pop out and they actually create some drag in that, you know, very low-Earth orbit, tenuous upper atmosphere. So, we were worried that the orbital lifetime wouldn’t be quite as long as we would like. And so one thing we did, we actually added ballast, just some extra weight, to our satellite. So the, the as-designed satellite was about eight pounds total, and we added another five pounds of just, of weight to it, to make it, you know, improve its mass to area ratio so that drag didn’t affect much. But anyway, during that time we were looking into various launch options, and so we applied to the Air Force’s Space Test Program, and they really liked our satellite, and they, you know, very quickly said, yeah, we’ll, we’ll include you on our next launch. OK. Actually, you know, the NASA launch, we applied for the CubeSat launch initiative launch, and it was about six months before they kind of came back and said congratulations, you know. But, you know, this STP launch, that, that came back like a, in a week. So now we got two launches, basically, you know, little to no cost to us, so [we thought] OK, well, we got two satellites, let’s just do it. So, you know, we, we had always hoped that if the opportunity came along we could launch our qualification model and, and, and do a second satellite. But, you know, I didn’t expect the opportunity to fall into my lap quite so, so quickly. So we just went ahead and, you know, chatted with the NASA folks and everybody was happy with this idea, hey, hey, we’re going to have two satellites — we want to do a constellation, we want to do like, you know, 10 or 20 satellites eventually. So let’s do two and try to get them where they, their missions overlap so we can kind of, you know, test, you know, having two satellites orbit looking at the same targets, higher frequency. And so that all worked out great. And you know, as I was saying, a little bit more simultaneous than we had been planning on, but, so yeah, we got two satellites.
Host: That’s great. You mentioned, you mentioned the challenges of low-Earth orbit with, with the extra drag and adding weight. Where, where did the other one launch? Is it in that same orbit and you had to work through the same things, or is, is it somewhere else?
Steve Love: Well, it’s a little, it’s a little higher.
Host: A little higher.
Steve Love: So, the first one is basically the space station orbit, so it’s about 400 and something kilometers up. And the second one is at a 500-kilometer orbit. So you know, about a little over 300 miles up. So, you know, at 500 kilometers, you know, we expect it to come down in, you know, maybe about three years. You know, these CubeSats are required to come down within, I believe it’s 20 years, so we don’t want them just turn to space junk.
Host: Right.
Steve Love: So we never get to launch them into super-high orbit. So we, you know, CubeSats go into fairly low orbits where we know their orbit will decay, and they’ll, you know, be out of the space junk picture before too long.
Host:[Laughter] I see. All right. Well, with two, with two satellites in orbit, you mentioned at the beginning of our talk you have to, you know, right now, you have two satellites in orbit, that’s great, you got to go through activating them and getting them online and everything. What is in store for what these satellites are actually going to do? Let’s talk about the science a little bit. What’s on board these, these hyperspectral imaging, and then what, what data are they going to be sending down to you so that you can do what?
Steve Love: OK, so, you know, the actual hyperspectral imagers, these are ultraviolet, visible, the 300-to-500 nanometers, which is basically, 500 nanometers is like a blue/green color, and then the spectral range extends into the near ultraviolet. And so in that spectral range you can see nitrogen dioxide, sulfur dioxide, ozone, formaldehyde; you can characterize aerosols, distinguish sort of clean, purely-scattering aerosols – that, you know, just scatter the, the sunlight — from sooty aerosols from fires that absorb sun, sunlight. And that’s a very important thing for the climate scientists. If you see an aerosol haze, what kind of, what kind of aerosol is it? Because the city ones absorb sunlight and add to the warming; the clean aerosols reflect sunlight and have a cooling effect. So being able to distinguish those is important. There’s several other volcanic gases. There’s chlorine oxide, bromine oxide, iodine oxide, and these are fairly new to remote sensoring of volcanic gases, so we’re going to be looking at those, too. So the instrument itself…we, you know, the T in TACOS is, is targeted. And so, we aimed this to fill a niche that this was kind of empty. So there are other satellites, large satellite instruments that have similar sorts of spectrometers on them, much bigger. The one we sort of modeled our capabilities on is one call, it’s the Ozone Monitoring Instrument, OMI, O-M-I. And that instrument, well, it’s about 150 pounds for the instrument itself, and I told you my, our satellite with added weight is only 13 pounds, but, you know, spectroscopically it’s very similar. But in terms of its imaging, its mission is to map the entire globe every day. So it does it at a very core spectral spatial resolution. So a single OMI pixel is over a hundred square miles; it’s about, what is it, about eight by 15 miles. So for instance, you know, the entire city of Washington, D.C. is about half of an OMI pixel.
Host: Oh, OK.
Steve Love: And so, we want to look at the same gases, but do it at much finer spatial resolution. So, the NACHOS single pixel is about, about a thousand feet on the side, basically — 300, 300 to 400 kilom, meters, excuse me, on a side. So it’s roughly, instead of being bigger than a city, it’s about the size of a big sports stadium. That’s, that’s the best object I can think of that’s about the size a NACHOS pick, pixel. OK. So we have, you know, these relatively tiny pixels, at least for this kind of space-based hyperspectral observation, and so now we can look at, you know, much smaller things, you know. Think about volcanoes. OK, so we can see sulfur dioxide and other volcanic gases, but now we can see things on this sort of more human scale. So, you know, instruments like OMI, they’ve measured gases from volcanoes but only for very big eruptions. So if the volcano explodes and generates this cloud that wraps around the globe, OMI and satellites like it can, can see that. But they can’t see a volcano that’s just waking up and just starting to fume a bit, you know, in the kind of state where vulcanologists would want to go in and, you know, stick their tubes into the fumaroles. But with NACHOS-sized pixels we can, we can see those early stages of a volcano waking up. So that’s one of the exciting things. And then, looking at, so we, we’ve kind of got two, two thrusts here: we got the vulcanology and then we have, you know, air pollution monitoring and indirectly looking at greenhouse gases. So, you know, our other main target gas is NO2. NO2, nitrogen dioxide, is, is the gas that makes smog look brown. OK. It’s, and it’s, you know, one, it’s toxic: most of the health effects of smog, you know, lung damage, asthma, COPD (chronic obstructive pulmonary disease) and so forth, are caused by NO2. NO2 and ozone, which actually NO2 is involved in making smog ozone. And so we’re interested in looking at NO2 production on this fine scale and understand, it’s kind of complex chemistry that goes on, you know? You know, NO2 or nitrogen oxides is very, you know, is various nitrogen oxides, and they’re produced by heating air really hot. So internal combustion engines, power plants that burn coal, those are kind of the chief, you know, manmade sources of NO2. Natural sources are things like lightning and forest fires and to some extent volcanoes too. Anytime you get air, which is nitrogen and oxygen, really hot, you’ll mix these nitro — nitrogen oxides. And so NO2 is a marker for burning. And, you know, particularly, you know, burning fossil fuels like an internal combustion engine or coal-fired power plants. And what’s nice about it is, it’s very easy to detect in the visible, ultraviolet region. It’s got a very strong and distinctive spectral signature. It’s much easier to detect than carbon dioxide itself, which is kind of tricky because there’s a lot of carbon dioxide in the atmosphere. So, you know, apart from, you know, the pollution monitoring aspect, or at least, you know, the actual toxicity of NO2, it’s also a really nice tracer for greenhouse gases. It’s not an important greenhouse gas in itself, but wherever you burn fossil fuels you make NO2 in addition to CO2. So, you know, it’s a way of, of tracking and quantifying fossil fuel burning.
Host: There’s a lot of components to this, and it seems like you’re measuring a lot. You’re talking about the instruments you have on board and NACHOS being able to, to monitor, to look at, to measure exactly what’s happening. But I wonder, to take it a step further, what are your hopes as you’re collecting these data and you’re getting a better understanding of, you know, where these gases are and, and you’re taking these measurements, and contributing these, these data to the scientific community, do you have any like hypothesis or goal or, or objective to, on how to compile these data and put something together to measure something? What, what, what are the goals of NACHO[S]?
Steve Love: I guess, you know, the overall goal is to measure these atmospheric chemistry processes at a much finer spatial scale that has been done before. At least that’s, that’s the atmospheric science side of it. And then in parallel, you know, for the vulcanology, this will really be the first time we can do real sort of eruption-warning kind of monitoring of volcanoes from space. You know, before everything that was done in terms of looking at volcanic gases is, is like, hey, you could see a big eruption after it happened, but you can’t see the, the lead up to it because that’s just too small. And so having that, you know, tiny pixel enables you to see the small early stuff. But with going back to the pollution monitoring side, as I mentioned, that’s the NO2, the nitrogen oxide chemistry, is kind of complex. You burn, you know, fossil fuel, you get the air hot, it makes NO; that reacts with the oxygen and the atmosphere to make NO2. If there’s sunlight, NO2 can react with the oxygen in the atmosphere again to make ozone in addition. And then depending on whether there’s sunlight or not, and, you know, the reactions can go either direction. And, you know, this is all happening on a much smaller spatial scale than any instrument currently in space, until NACHOS, could, could resolve. So, you know, all these existing instruments have sort of city-sized pixels, and now we’ve got stadium-sized pixels. And so now we can actually, we hope, you know, actually see this chemistry going on in a spatially-resolved way and be able to feed that into air quality models, for instance; understand what the real chemistry is on this fine spatial scale as, you know, you convert from NO to NO2 to ozone, then go back and, and so forth.
Host: So now I’m getting a better understanding of why that constellation idea that, that hope for, for, for you guys is, is your next goal really. It sounds, sounds like the two, with these very fine measurements, you’re adding to the, you know, the scientific community something that hasn’t been contributed before on this smaller scale. But maybe I’m, I’m right in interpreting that with more satellites you get this fine coverage over a wider area in a shorter amount of time. So is that really your objective with this effort to try to get more satellites up there?
Steve Love: That is exactly it, yes. Yeah, because we have this, you know, telephoto kind of look at things, we can’t cover lots of area with one satellite. We look at targets, you know, individual targets, and, you know, exactly when we can. We can’t look at the whole world at once, but, you know, the more satellites we have the more things we can look at and the more frequently we can look at them. So we would like to be able to, for instance, watch a volcano as it’s, you know, goes through its process of becoming more active, or watch this pollution chemistry in a city over the course of days or over the course of a day, you know, because sunlight play such a role in, in this chemistry and you know, what people are doing during the course of the day matters as well. And, you know, with one satellite you might be able to look at a given target once a day maybe; so, you know, having ten satellites, you might be able to look at the same target ten times a day at this, you know, much finer spatial resolution.
Host: I understand. So it’s more, it’s more coverage, but then it’s, it’s, it’s more regular intervals of, of monitoring some of these locations as well. And that’s, and that’s good for the data.
Steve Love: Right.
Host: OK. Very good.
Steve Love: Yeah.
Host: There’s a lot of ambition here, Steve. Lots, lots to do. And I, and I wonder, I want to end on just sort of a broader picture here on, you know, you spend a lot of time on, on working on these technology and, and now you have a chance to contribute some unique data to the scientific community. I wonder, when you think about just the pursuit of, of space as a, as a place to make these measurements and the open opportunity you have to get launches, as you said, for, for very little cost to the, to the university, to the laboratory, so it’s just, there’s, there’s a lot, there’s a lot of open opportunity and it seems like it’s something that’s important for scientists to pursue, to have a better understanding of, of our planet. What is your hope for NACHOS in what, you know, what, you know, Los Alamos and what NACHOS are able to contribute to the scientific community, whether it’s something broader like, you know, observing and adding to the data of climate change or just a better understanding of our planet, what are your hopes for the experiment specifically?
Steve Love: Yeah, well, I mean, a better understanding of our planet, definitely. You know, specifically, I mean, I’m, I’m really excited about the improved spatial resolution and what you can do with being able to see finer details. And we were actually fairly conservative with what kind of lens we put on the front of our instrument. And that was, that was all driven by what we thought our satellite could do in terms of pointing at a target accurately. So we chose a 15-degree field of view, which is about like a moderate telephoto lens on a camera, like a portrait lens, like. But there’s nothing optical about, that says we couldn’t make, put a much bigger telephoto lens on, on, on our instrument. And we are, you know, expecting to get much better pointing accuracy than we were ex, you know, imagining when we first started this project. So we could actually do much finer spatial resolution than stadium-sized pixels; that would be fairly easy to do. So, you know, I’m excited about being able to resolve, you know, the, this pollution chemistry, how these gases are formed on, you know, sort of this, you know, neighborhood scale rather than just a big blotch that’s, you know, one pixel is a city…
Host: Yeah.
Steve Love:…being able to understand that. I, I’m very, you know, especially excited about being able to look at volcanoes and, in that sort of detail, and, you know, not just for eruption prediction but for understanding of volcanoes and, and hopefully spotting things that, you know, haven’t been spotted before. Like lots of volcanoes have vents that open up on the flanks of volcanoes away from the main crater; we could spot those from space. We can, you know, from space you could look at, you know, all these remote volcanoes that, you know, you can’t send a crew of vulcanologists every one of these things. You know, the, the big ones, the main ones that are close to cities, you know, of course, the geologists are keeping a close eye on those, but there’s, you know, hundreds of volcanoes around the world and being able to monitor all of them, you know, from space on a regular basis, like you could do with a constellation, that would be wonderful.
Host: That would be. That’s great. You’re excited for the data. And, and I think more so, I think what, what’s coming out to me and, and what I’m sort of locking onto is your early fascination with space and your early fascination with volcanoes. You get to explore that now. That’s, that’s what you have ahead of you and I think that’s, that sounds really exciting. So, Steve Love, it’s been an absolute pleasure to, to talk with you today, learn more about NACHOS and, you know, after two, the successful deployments of, of both of the satellites you got some very interesting data that you’re going to be collecting heading your way very soon. So, it, it seems like a very exciting time, and I’m, and I’m glad to be able to share that with you. Thanks for coming on.
Steve Love: Well, thanks a lot.
[Music]
Host: Hey, thanks for sticking around. Learned a lot from Steve Love today about the NACHOS experiment. Some great data is going to be coming down, and in fact at this point might already be coming down from the satellites. So Steve and his group will be making some observations and hopefully adding to the great scientific community what’s going on with volcanoes and air quality in cities. So some interesting stuff coming, thanks to the opportunities on the International Space Station and these different launch opportunities, and of course, his work to minimize the technology to get it on a CubeSat. You can check out NASA.gov/iss for the latest opportunities on International Space Station. And in fact, there’s a tab there that you can look at specifically the research and what we’re doing, and even Earth sciences and Earth research that have been enabled through some of the opportunities aboard the International Space Station. Of course, you can check out the many podcasts we have across the agency at NASA.gov/podcasts. You can find us there, Houston We Have a Podcast, and listen to any of our collection of episodes in no particular order. We have a lot of different topics that we’ve been covering throughout these past more than five years at this point. You can also talk to us and suggest topics or ask questions by visiting us at social media sites. We’re at the NASA Johnson Space Center pages of Facebook, Twitter, and Instagram. And you can use the hashtag #AskNASA on your favorite platform to submit those questions or maybe suggest some topics, and just make sure to mention it’s for us, though, at Houston We Have a Podcast. This episode was recorded on July 26, 2022. Thanks to Will Flato, Pat Ryan, Heidi Lavelle, Belinda Pulido, and Jaden Jennings. And of course, thanks again to Steve Love for taking the time to come on the show. Give us a rating and feedback on whatever platform you’re listening to us on and tell us what you think of our podcast. We’ll be back next week.