A conversation with Marc Murbach, the Principal Investigator for the Technology Education Satellite (TechEdSat) based at NASA’s Ames Research Center in Silicon Valley.
Transcript
Matthew Buffington (Host):You are listening to NASA in Silicon Valley, episode 38. Technology drives exploration. That is particularly relevant to the relatively new small satellite platform. Of which, our guest today is Marc Murbach, who is the Principal Investigator for the TechEdSat, which stands for the Technology Education Satellite.
This investigation uses a small CubeSat spacecraft, launched from the International Space Station, to evaluate, demonstrate and validate new technologies. Marc works with a wide range of groups to build and launch small satellites. Some from the scientific community and NASA itself, but many are high school and college students, as well. We are on the ground floor for this up and coming technology that is making space more accessible to scientists and the public. Here is Marc Murbach.
[Music]
Host: We always like to start this off with getting to know you a little bit.
Marc Murbach: Okay.
Host: Tell us a little bit about how you came to Silicon Valley, how you ended up at NASA.
Marc Murbach: Basically, I’m from Washington State, but I was raised in South America, in Ecuador and Peru. My folks were in the foreign service. Even as a kid, I remember there was a NASA installation that actually was part of the ground station, and I remember being enthralled by that. I was very interested in science and engineering.
Eventually, I was attracted to NASA space exploration and started my career to NASA Ames. I’ve been interested in thermodynamics, very high-speed flight, reentry flight, planetary exploration, mission design. I’m a hands-on guy, so to me, it was important to go back to some of the beginning part of NASA and the NACA, the predecessor organization, so that we can actually build things, test things rapidly, and experiment, and thus learn very quickly.
Host: Growing up in the foreign service, living in Ecuador, I imagine you went to a bunch of international schools and working with different people. When you went to university, did you study engineering, or was it always centrally focus of “Man, I’m going to go work for NASA one day”?
Marc Murbach: I would say pretty much so. Pretty much the latter.
Host: [Laughs]
Marc Murbach: I was really interested in a science and engineering career, but I’m very interested in world culture and politics and history in particular, and I do teach on the side, so I’m an adjunct professor at a local university, and my poor victim students they have to learn a bit of space history, which I make relevant with a calculation, and then they get it. It’s a neat platform with which to better kind of illustrate these otherwise dry equations, now come to life over a period of decades. It’s fun to do it that way.
Host: Well, it seems like a mix of the science of the math, the calculations, but then also, I could tell you like to tinker.
Marc Murbach: Absolutely.
Host:… and play with the toys.
Marc Murbach: Yeah.
Host: So it’s almost like engineering and then the science. Were you always kind of dealing with both?
Marc Murbach: I would say so. I think one engenders advancement in the other. The space program is very much like that. At first, we could barely target the Moon, failing numerous times. Mars also. The Russians have had horrible luck at Mars. But each time we go there, what we’re studying comes in better and better focus, just like our Kepler instruments here at NASA Ames. For decades, we presumed that there were planets out there, but we were never really sure until we started seeing these, and it’s a plethora of them. It’s wonderful. It’s very, very exciting.
Host: Well, it’s also fascinating because I remember even thinking of Kepler that the pitch, the idea for that mission, it failed. It didn’t get approved. It went a handful of times until, “All right, this version is good to go,” and then you make it happen.
Marc Murbach: In fact, we learned a lot from Bill Borucki, who’s the PI [principal investigator] on that. Many years ago I was helping Bill on something that was an optical bench on plywood, which is an oxymoron, but the ideas had to be tested somewhere. Then, gradually and gradually, the CCD technology advanced, and I think, after 18 or 20 years of proposing, finally, the combination of technologies mature, and all of a sudden, we have this marvelous, marvelous and inexpensive telescope that NASA’s provided.
Host: It seems like a good analogue for Ames, even as a research center. It’s that you try it; you research; you figure it out. If it doesn’t work, go back to the drawing board, do it again. Sometimes going back to the drawing board, it helps drive that innovation, coming up with different ideas.
Marc Murbach: It does. Typically, all these things advance by increment, and we see this very much even going back to the Wright Brothers.
Host: Totally.
Marc Murbach: If we compare him to Samuel Langley, who had a lot of resources at his hand, he tried a couple of point designs with some clever people, but basically dropped these steam-powered aerodromes into the Potomac in front of Congress, which is not a really good thing to do.
The Wright Brothers, learning from Otto Lilienthal, they became hang-glider pilots at Kill Devil Hills in North Carolina.
Host: North Carolina, yeah.
Marc Murbach: So they were trying to take the risk out of it, but they learned. As they learned aerodynamics very experimentally, incrementally, then they could add powered flight. They built their own 12-horsepower engine, but it was a series of incremental advances that they did, which makes sense. They built their own wind tunnels.
Then again, going back, moving four decades, just so you know, the nanosatellites are something like this. We can now really access the space environment, and we can test new sensors, new devices, and in our case as well, new methods of de-orbiting objects using a parachute, of all things, so we can actually parachute things off a space platform, which also sounds counterintuitive as well.
Host: Looking at some of the stuff that you’re working on now, these small sats or the smaller-scale missions, were you always working on that when you first came to NASA, or did it eventually kind of steer towards that path?
Marc Murbach: This was a fairly opportunistic a dear friend and colleague of mine by the name of Bob Twiggs came up with the idea of this containerized cargo, or containerized risk, as I like to put it. Inside these containers, we can put these nanosatellites, and what it does is it minimizes the risk to the mother launch vehicle, which is huge. By standardizing these shapes in the containers, it enabled dozens of these nanosatellites to be built, which meant that now academia – and also industry and NASA – have access to being able to do these rapid and quick experiments.
It’s a huge learning opportunity as well. Now we can get people early on in their careers to actually tinker, to think about how to do things. Our group is kind of a small skunkworks group, and we have a lot of students, hence the moniker TechEdSat, Tech Education Satellite, which we’re very true to, so we have a lot of interns, young professionals. Actually, early in their career, they get a chance to take risk, build it, learn project management at this scale, and turn things around very rapidly. And it’s thrilling.
Host: Maybe go a little bit more into that. TechEd satellite. That’s a program, and the whole purpose is to get students in to start making these small sats?
Marc Murbach: That’s correct, and us, too, so it’s joint, because we’re learning as we go forth as well. We polish what we’re doing, but we’re also being able to advance our own experiments as well, so it’s a nice environment, a nice learning platform for all involved. It’s incremental advancement, as I was pointing to earlier.
Host: Yeah. A lot of this stuff is stuff that you get off the shelf, or it’s accessible.
Marc Murbach: It is. What I’m holding in front of you right now is TechEdSat, actually number 7, which is a 2-unit size or 2-liter size. You can see the relative simplicity. We now can fill these with different kinds of experiments. We’ve standardized some elements of it. We’ve been able to really advance communicating to these. Inadvertently, some of our most interesting experiments have been communication experiments. We use a satellite network. Actually, we send email commands to our satellites. We’re the first email-commanded satellite.
Host: For folks who are listening, what we’re sitting looking at in front of us and we can link to different photos from the transcript and from the podcast is like a 10 by 10-centimeter cube or 10 by 10 by 10 cube, but we got one that looks like just two of them stacked on top of each other. It’s about the size of maybe half of a loaf of bread, give or take, depending on…
Marc Murbach: Yeah.
Host:… how big your bread is. [Laughs]
Marc Murbach: Yeah. It is that. Each unit of a nanosatellite is a liter, 10 by 10 by 10 centimeters, as you say. But now, with our extrusion, we can make these. What you’re looking at is a 2-liter. We typically make 3-liter satellites. Now we’re designing a 6-liter satellite, so it’s longer yet.
Host: Oh, really?
Marc Murbach: Sure.
Host: This is a standardized size. How does having that standardization help to build this community?
Marc Murbach: It’s huge. The cross-section is 10 by 10 centimeters, and we can make these long, so our colleagues in the industry now are able to launch six or seven units per launch tube. Therefore, you can pack more instrumentation, different kinds of sensors, maybe bigger optics, but what that does is, because it fits in these launch tubes, these launch tubes then have been taken to very rigorous safety, and any risk is contained within those launch tubes, those ejectors.
Host: Where are those? Is that up on the International Space Station that they’re getting launched from?
Marc Murbach: That’s correct. Now, it’s become common now that we can launch these off different launch vehicles as well, independently. Our sat actually is taken up as cargo to the space station and processed internally, and then it goes outside on the Japanese module arm, the JEMRMS. Then there are typically eight launch tubes on this arm, and then we populate part of one launch tube. For example, we can get 48 units or 48 liters per airlock cycle, which is great. It’s pretty cool.
Host: Oh, wow. I guess the idea typically is as we’re sending equipment up to the space station, then this isn’t necessarily the primary payload, but it’s kind of hitching a ride, filling in the gaps of stuff that’s already going up. There’s space, so might as well fill it with this.
Marc Murbach: Absolutely. We’re hitchhikers.
Host: Nice.
Marc Murbach: These are rides of opportunity. In fact, that’s how it usually works. This 2U, we were approached, says, “Hey, we have an empty space 2U. Are you interested?” That evening we started to lay out and started to go forth with the design, and now you have it in front of you. We did that in very short order.
Host: Kind of like, if you think of a Schoolhouse Rock, how a bill becomes a law, how a small sat gets into the sky.
Marc Murbach: Uh-huh.
Host: I mean, it basically comes from a conception and idea from a student or from a researcher from NASA or from anybody else. They come up with this. They build it, design it. It gets into a rocket, goes up, gets launched, does what it needs to do, and comes back.
Marc Murbach: Pretty much. It will burn up on the way down, by way of a caveat, but we do adhere to the tried-and-true manner of coffee-stained napkins.
Host: Nice.
Marc Murbach: That’s usually where it starts. Then we lay it out and block diagrams and advance. We have a particular approach to the structure. The structure that you see here is a square aluminum tube that we can cut, so it’s very easy for us to make the structure and to then focus on what’s inside.
You mentioned earlier, yes, a lot of the microprocessors that we use are maker-type microprocessors. We use Arduino processors and their family, which are very available, and also the Intel Edison processor. We’ll be the first to fly that. These components are fairly inexpensive, but we do have to be very careful, because if they get knocked on the head with a galactic cosmic ray event, then they will reset themselves. We’ve seen this a couple of times. But the whole idea is we don’t have to use radiation-hardened microprocessors or components. Our missions are of short duration, so if we’re conked in the head and even if we lose a satellite, which we have not yet…
Host: It’s not the end of the world.
Marc Murbach: It’s not the end of the world. It has not been a big investment.
Host: Yeah. It’s not like a multimillion-dollar taxpayer-funded endeavor.
Marc Murbach: Not at all.
Host: You can kind of get a little bit more risky or try a little bit more… spread your wings a little.
Marc Murbach: Absolutely. What we’ve been promoting is to do these a few times ahead of the bigger satellites. Then we can actually take the risk out of the bigger satellites or the interplanetary missions. Then one of our interests also is to take these and land a couple of versions of this on the surface of Mars.
Host: Okay.
Marc Murbach: So now, taking the idea of a nanosatellite and actually putting it on the surface of Mars is of interest. You can do a lot of very, very interesting things in 2 or 3 liters of volume. We’ve proposed that as well.
Host: Looking at some of the small sats, what are the typical applications that you’d see for space or even for Earth?
Marc Murbach: Well, I think perhaps a couple different levels. One is the pure experiment basically taking things up there to try out new communications systems, new sensors, new paradigms. It’s an act of laboratory for us and for a lot of other people.
Now, actually, some of our former associates and interns have actually gone off and spun off companies, and now they’re flying fleets of these satellites, usually with optics. So we’re looking at basically some imagery on-demand at different levels of resolution. That’s become very popular. Remote sensing has become a big deal.
As we make progress with the communication element of it and can get more and more data down per small satellite, then we can look at what’s called multispectral imaging as well, that have, of course, much, much more data. It’s all about data and science, right?
Host: Yeah.
Marc Murbach: So there are very practical commercial and sensing capabilities that are coming out from this very modest size.
Host: It seems like a big advantage of, at least you think of, a large satellite that’s looking at the Earth or at another planet, and it’s focusing one very expensive sensor, looking at one part. But with these small sats, you could as you said, almost like a fleet or a hive of them that are getting tons of data points over a larger space.
Marc Murbach: Correct. That’s also an experiment. At NASA Ames, we’ve developed a project called NODeS, where we’re trying to understand a little bit better and perhaps be able to have the attitude control, so you can do a lot of other very interesting things. That’s still in the experimental realm, but then eventually this will be matured and harvested for maybe small satellites. We’re going to see an abundance of small communication and remote-sensing satellites in medium-low-Earth orbit.
Host: What’s the typical lifecycle for this? It’s like a year, a couple months?
Marc Murbach: The good thing about these – if you launch something from a space station, typically, the durations are about six months, and that’s about right, because the last thing we want to do is to contribute to space debris, space junk. The nice thing about these orbits from a space station is that they can be very risky; sometimes we’ve seen a lot of things that don’t work or don’t work the first time, but that’s okay. They get washed out after a few months, and that’s perfect. Then they can try it again.
In fact, stepping back, what I didn’t mention is, before I worked with the CubeSat paradigm, NASA has a very active program in suborbital rockets, and so we fly 20 to 30 per year from the NASA Wallops facility, and I’ve built numerous experiments on those platforms. Those are shorter duration. Maybe you get 5 minutes, 10 minutes of microgravity or time above the atmosphere.
What the nanosatellite has done is really then taking this concept, and now, hey, instead of just a few minutes, we can extend this to much, much longer time. It’s smaller. Now we know aperture sizes have to be 10-by-10 centimeters, but you can do a lot of good stuff with it.
Two things. One is a natural, I think, growth from the suborbital program that was that risky part of small projects. Actually, it’s still viable. I still have an active interest in active experiments on rockets, because we want to see those advanced. Actually, we even have a project where we’re looking at avionics sized about the size of this satellite, 1 or 2 liters, and then that actually is cheap avionics set to control suborbital rockets or orbital rockets, and so we see that as well. That’s an exciting potential application.
Host: Even thinking of the CubeSat not a cube; it’s a rectangle sat… [Laughs]
Marc Murbach: Rectangular sat. Yeah.
Host: Sitting in front of us, normally, the end of that lifecycle is, it’s done its job. Now it’s burning up in the atmosphere, just evaporates on its way coming back in. But you’re working on ways to prevent that, to actually have a brake or a parachute or how…
Marc Murbach: Correct. Our longer-term ambition is to look at things like a sample return from orbiting platforms or manufacturing depots or space stations, but to do that, at first, we want to be able to control the de-orbit part of it and not necessarily use the typical rocket propulsion, which we can do, but it turns out it’s a lot more complicated.
If we can do this with a simple drag device, and do it accurately… so our next experiment, like the Wright Brothers in a loose sense, we can warp the wing. We can warp the parachute so that we can target a point at the top of the atmosphere in preparation for our future experiments that we would actually try to get these to go all the way down and eventually recover them. But at present we have to promise everything’s going to burn up, because we want to be good citizens.
Host: Yes. Yes. We don’t want to put more trash up in space.
Marc Murbach: Right, or drop things where they’re not supposed to be. In fact, on this satellite right here in front of you, we actually have an ablator on the front end, so this white piece that you see here is an ablator.
Host: Okay. An ablator is…
Marc Murbach: It’s a heat shield basically where the high rate of heat transfer starts to, in this case, sublime and start to erode away, but protecting the satellite behind it.
Host: Okay.
Marc Murbach: We do this incrementally. This will burn up, but it will burn up deeper and deeper, in our successive experiments… Again incrementally, we will probe and go deeper and deeper and deeper, yeah, so that, in a couple satellites from now, we would like to actually have the thing touch the ground.
Host: It’s those baby steps of first, let’s see if we can control where this thing burns up as they come in, see how long it takes to burn up, and then, eventually down the road, how can we actually recover…
Marc Murbach: Exactly.
Host:…and bring it back, but with control and understanding?
Marc Murbach: But with control. These next couple of experiments are all about what we call the exo-brake, or parachute, and controlling it, and then convincing people that we know what we’re doing. We can target it. We can actually fly through the thermosphere, which has a variable density. It’s a lot of fun. Actually, this next flight will be really cool, because we’ll have our operations meetings every day and talk about the space weather, literally, which will tell us the thickness of the atmosphere and whether or not we need to change the parachute. We will steer it in the sense that we have a brake pedal, and then we run trajectory simulation to see if we are going to hit our target or not. It’s going to be a lot of fun.
Host: Is that the main thing, if you’re looking a couple years into the future, 5 years, even 10 years? What do you see for these small sats? Where are you hoping that they’re going to eventually go?
Marc Murbach: I think, again, as a platform, who knows what people will come up with, both new experiments and maybe new industries. I think, eventually, on-orbit manufacturing… we see that there are some real promising signs. We’ve seen it discussed for many, many years, but also having the practicality of having something in orbit and be able to retrieve it is going to be important.
Host: Yeah.
Marc Murbach: There’ll be an experimental phase at first. But then actually taking these things off, as we send ships off to Mars, for example, and other planets, to be able to deploy smaller sats and get academia and students involved in these, as a safe subset of the larger mother-craft, is going to be important.
If we can, for example, take these things, as we’re interested, and putting them on Mars and doing unique Mars climatology and Mars experiments we’re looking into miniaturizations of these mineralogy experiments that we’ve been able to perform, some actually very good work here at NASA Ames. We can extend that concept in low-Earth orbit, again with academia, and containing the risk to the mother-craft, and put these things on Mars. Then Mars they talk to the mothership. The mothership talks back to Earth. Then we can close the communication link that way.
Host: Cool. For folks who are listening who want to find out more about some of the work that you’re doing, more about the TechEdSats, best place to go nasa.gov?
Marc Murbach: Yes. We also have a TechEdSat website, so if you also search TechEdSat, you’ll no doubt find us.
Host: Excellent. We can add that to the show notes so people can find it. Also, if people were listening, a faster, easier way, if you have questions for Marc, we’re on Twitter at @NASAAmes, and we’re using the hashtag #NASASiliconValley. Feel free to send Marc any questions. We’ll loop him in.
Marc Murbach: Be more than happy to answer those. Thank you very much for inviting me, and thank you all for your very kind interest. We’re looking forward to the next couple of very exciting missions.
Host: Well, I can tell this will be the first of many, because this stuff is just growing like crazy. It’s just fascinating.
Marc Murbach: We’re having fun.
Host: Thanks.
Marc Murbach: Thank you.
[End]