Man set foot on the moon in 1969, and since then we’ve been reaching ever deeper into our solar system. Learn about Georgia Tech's space travel and technological innovations happening at the School of Aerospace Engineering with professor Brian Gunter.
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Steve McLaughlin: You're listening to The Uncommon Engineer. I'm your host, Steve McLaughlin, dean of the college.
Male Speaker: We’re just absolutely pleased as Punch to have you with us. Please say a few words.
Male Speaker: Sounds like Georgia Tech is kind of a mini NASA.
Male Speaker: We’re going to plan a [indistinct] run and do this CDH burn. [inaudible] have not heard anything.
Male Speaker: Now pressurizing and we’re coming up on the power transfer. Making a final check of his computer. 10-9- We have ignition sequence start. Engines on 5-4-3-2- All engines running. Launch commit. Liftoff. We have liftoff, 29 minutes past the hour.
Steve McLaughlin: Man set foot on the moon in 1969. And since then, we've been reaching ever deeper into our solar system. We're discovering evidence of water on Mars. We’ve stepped beyond our stellar neighborhood with Voyager 1, the only Earth object to reach interstellar space. And now, yes, we're exploring commercialized space travel.
Male Speaker: You’re looking beautiful.
Steve McLaughlin: Welcome to The Uncommon Engineer—conversations about the impact Georgia Tech engineers are having on people and society in maybe in ways that you don't expect. I'm Steve McLaughlin, dean of the Georgia Tech College of Engineering. Today we're here to talk to Professor Brian Gunter from the Georgia Tech Guggenheim School of Aerospace Engineering. Brian Gunter, welcome to The Uncommon Engineer.
Brian Gunter: Thank you for having me.
Male Speaker: Flight crew-OTC-Close and lock your visors, initiate O2 flow.
Male Speaker: Roger, Hawaii, reading you loud and clear also.
Steve McLaughlin: You know we hear lots in the news about space missions and launches, whether it's a space shuttle, you know, Elon Musk in certainly in the news a lot around SpaceX, and I understand you're involved with SpaceX on a project. Can you talk about that?
Brian Gunter: That's right. We have, in development at Georgia Tech, a small satellite mission. It’s called the Ranging and Nanosatellite Guidance Experiment. And I'll get into some of the details in a second. But it is a small satellite—think of a satellite that's maybe the size of a large coffee cup, and there are two of these together. So together, they're about the size of a loaf of bread. They will be launching on a Falcon 9 rocket which is made by SpaceX. And that should be launching in the fall of 2018. The specifics are you have to be very flexible when you launch satellites because the dates always change. The RANGE mission is—think of these two small satellites and the goal of the mission is all about getting precise, absolute, and relative positioning. So most small satellites only know their position in space to tens of meters, and we want to get that down to centimeters. So we want to know where these satellites are at any point in time down to centimeters. And in addition, we want to know, because there are two of them and they're flying together in this sort of leader-follower formation, we want to know how close they are with respect to each other down to millimeters. And so we have all this instrumentation—we have the laser rangefinder on there. We have a miniaturized atomic clock, which we think is the first one that will fly in space. We're also testing various secondary experiments. A lot of it is—a lot of the operation of the satellites are going to be autonomous. So they're so small, we only contact them maybe five or ten minutes a day. So the rest of the day they have to work on their own. And to maintain their formation—let's say we want them fixed at 10 kilometers apart, they have to do a lot of that themselves. And so there's a lot of interesting development that goes on with that. And there's no propulsion systems on these small satellites, so they have to do what's called “differential drag” where, even though you're in space, there is a small amount of atmosphere, and you're going 7 kilometers per second, so you're really moving fast so even the smallest bit of atmosphere is still interesting or still can create a force on the satellite. So what we do is we'll turn the satellites and given a little bit different area that is heading into the drag forces. So because of that, then we can stretch things back and forth.
Steve McLaughlin: So you have students in your lab that are making these satellites and interacting with SpaceX. What’s it like to interact with SpaceX? You mentioned you got to be patient.
Brian Gunter: So we were—the mission itself was accepted as part of—we got the launch. We had to build a satellite, but we got the launch awarded to us through a proposal, through what was, at the time, the Skybox-CubeSat Partnership. So Skybox was a company; it's now owned by a company called Planet. And for those who maybe follow satellite remote sensing, Planet is now a company who has a number of orbiting imaging satellites that are constantly taking high-resolution images of the Earth. So they—basically we got the launch through them, and they awarded us a launch on one of their following satellites because they have larger satellites, and we go along on what's called a “ride share.”
Primary customer and then our small university satellite go wherever there's space on the rocket and there’s extra mass. And so the way that SpaceX came into be is originally we were supposed to launch on an Orbital ATK rocket. And so it was going to be Skybox, now Planet, that was going to pay for the primary rocket, and we were going to be a ride share on that.
Then, as we've learned, a number of launch delays because you're waiting on the primary customer. So you don't have any choice on when and how you go up. And so things change. So things were rescheduled. Plans changed and so we moved from an Orbital ATK launch to now this launch that's called the Space Flight SSO-A, what they're calling the SmallSat Express, and that is going up on this Falcon 9. And that's a dedicated mission that's operated by a company called Spaceflight Incorporated. So the way it works is we interact with what's called the “launch service provider,” and Spaceflight is that company. And then they interact with the SpaceX, the rocket provider.
Steve McLaughlin: So you talked a little bit about the, you know, the fact that you're going to launch these two satellites, and the goal is to run some experiments that help finally control position or where they're located down to a small scale. Do I have that right as the goal or purpose?
Brian Gunter: That's correct. So the primary mission of the mission is this relative and absolute positioning. So we want to find out how to control or how to position, know where the position of these small satellites are to a level that has never been done before for these small satellites. So that in itself is an enabling technology. It's one of these characteristics about a satellite system that if you know that, then you can enable a number of different other mission concepts. So think of very tightly controlled formations. Think of constellations, or think of—like we talked about earlier—where you have coordinated measurements, and you need to know precisely where things are so that you can take, whether it's images or whether it's ranging data in a very coordinated and precise manner. And so sometimes you need to know that level down to centimeters.
The secondary part of these missions that many of these CubSats are technology demonstration missions. So you are testing out whether new components are going to function in space, whether they do what you think they do. So we have several like I mentioned. One was a miniaturized atomic clock. Another is a laser ranging system. And this laser ranging system also caught the attention of the Navy. So we had a follow-on grant from the Office of Naval Research. And what we're doing with this is for the same laser that we're using to inter-satellite ranging—so think of a range finder that you might get at a hardware store or something like that—except now we're posing this over many hundreds of kilometers possibly. That same laser can be used, if you think about it—pulsing it on and off can be zeroes and ones—so it essentially doubles as a laser communication system. And that's what the Navy was interested in. So we're also demonstrating what we hope to be the first inter-satellite or cross-link laser communication system. And that’ll be a very low rate. It's not going to break any speed records, but it will demonstrate the lengths. It'll demonstrate the technology whether these small components that you can just literally hold in your hand, could they service as a laser communication system.
Steve McLaughlin: So you're living proof of, you know, when NASA goes to Congress every year to kind of justify that, hey you know, what we're doing in space matters. It's not just the mission, but it's the things that you learn along the way. And you're testing—sounds like you're testing a number of those enabling technologies that even separate from your, you know, the project per se, you're demonstrating new things to even solve your mission, and you're living proof of why we need to support NASA.
Male Speaker: 11-Houston. If you could comply, we’d like to see some smiling faces up there.
Male Speaker: OK, we’ll reconfigure the PB for that.
Male Speaker: Roger.
Steve McLaughlin: Where do you think manned space flight is headed? You keep hearing about possible manned missions to Mars, but what about some of the other planets. Where do you see if you look in your crystal ball for, not just 20 years but 100 years, you know, where is man headed?
Brian Gunter: Well I think in the in the near term most missions are going to be robotic. The reason why is the space environment is extremely harsh. So we know this. It has extremes in temperatures. There's radiation and, of course, there's not this breathable atmosphere or food sources readily available, so you have to build spacecraft that bring all of that along with you to project the astronauts or the humans that are on the trip plus bring all the food and water and air that they need for the journey, not just there, but also coming back as well. So it becomes very expensive. So just to give an example, if you go to the SpaceX website, since we're talking about SpaceX, the Falcon Heavy, which is this next generation of a very heavy lift rocket vehicle, it can carry, according to their website, 37,000 pounds to Mars. And if you think about what a mission would cost—a manned mission anywhere: Mars, even to the moon—you could think of billions of dollars. To put it in perspective, the Cassini mission which was wonderfully successful and just finished up its operations, that was around $3.3 billion for that mission. So you would expect it would be at least as complex and expensive as the Cassini mission if you're sending humans.
And at just 37,000 pounds when you do the math at say a four billion mission cost, you're talking about spending roughly anywhere from 50 to 100 thousand dollars per pound of mass. So it gets really expensive. In addition, there are some very other sort of physiological and psychological challenges that go with manned spaceflight that maybe a lot of people don't know. The human body isn't meant to exist for long periods in zero gravity. We’re meant to be here on Earth. So there's problems with bone densities, muscle mass. There's also been documented cases with problems with eye pressure causing permanent damage. There are interrupted sleep cycles because you're not on this Earth cycle of day and night. And so it's very—there are certain things that have to be overcome before we send somebody off. And a round trip mission to Mars, you can expect to be maybe three years going there and back.
And there are some also some psychological challenges. Basically in a solitary confinement for three years as an individual, and that's very difficult to overcome. When they screen people to be astronauts, their psychological makeup is just as important as what their technical skills might be. So that said, I think the challenges for human exploration are not insurmountable. And I believe the technology is there to do that, or can be developed in the near term to put humans on Mars or other celestial bodies. We don't have to go to Mars—we could go to asteroids and comets—these are also been proposed. And sometimes they are a lot easier because, if you go to Mars, you go to a very large planet that has a large gravity that you have to overcome to return flight. But if you were to land on an asteroid that there is no large, you know, gravity, getting off of it is much easier. But I think it just needs the investment and the support behind it. So I think we can do it; it's just very expensive.
Steve McLaughlin: You know, missions to other planets, what are the other kinds of things that you see out there either that you're working on or that Georgia Tech is working on or things that maybe our listeners haven't heard about?
Brian Gunter: Well, I would say, since we're talking about, you know, manned and robotic missions, I would I would also argue that there are still a tremendous amount of things that robotic missions can do, and some of them that they should be doing instead of humans. So not everything is something that we should do with manned exploration. And one of them, for example is, let's say, an orbiting imager like we've talked about, that you're just gathering real-time information that's up there for decades at a time gathering 24/7 data 365 days a year. That information is best done by robotic missions. And so, sort of the link to that is some of the work that maybe is not so known where we use remote sensing. So I am part of also, yes, I build satellites and we have this whole CubeSat and small satellite program, but another aspect of what I do is actually using the data from those missions. And because they’re launch for a reason, and a couple of good examples are some NASA missions that I've been involved with in the past—the GRACE mission and the ICESat mission. GRACE was a mission that was designed to observe the time-variable gravity of the Earth. And that's important because anything that moves on the surface of the Earth—water, snow, ice, oceans—it's all mass, and mass and gravity are linked. So when you observe the time-variable nature of Earth—the time-variability of it—you are also understanding what are the processes that are causing that change in the gravity.
And so we use that remote sensing data from these NASA missions to observe all sorts of things that people may not know about. One of them is I study the motion of the ice mass and solid-earth changes in Antarctica. And you may ask, “Why are we interested in, you know, the changes in ice and the solid-earth in Antarctica?” And the answer is that it has a direct influence on the rest of the world in terms of sea level change because it's so like a cup and Antarctica is, if you were to put a ping pong ball in a glass of water and you push it down, the water would rise; pull it up, and it would it would lower. And Antarctica is a very large continent. It has 70 percent of the world's freshwater on it. And so observing the changes in Antarctica directly influence our understanding of the water cycle, sea level change, climate change—all of this.
So we've been using that data and, for time, variable gravity. We can use it to observe. And gravity is an interesting observation because it doesn't—it's not limited by a camera like a camera is limited by its line of vision. So if it's something underneath a tree you're not necessarily going to see it. But gravity is insensitive to that. So we can observe changes in underground aquifers. So we can monitor let's say large, the behavior of large river basins or large aquifers that we depend on for agriculture, for food production. And so this type of remote sensing data, looking at the data that comes from these major NASA missions is also another one of our major objectives. And I’ll also say that the ICESat and GRACE missions that I've been working with, they have now follow-on missions. So Grace follow-on just launched a few months ago or a couple of months ago in early 2018, and ICESat 2 is set to launch later this fall in 2018. So these two missions will continue to, not just look at Antarctica, but do global mapping and global—and ICESat, I didn't mention, but it measures the topography. It's using LIDAR systems to measure the changes in the surface and the volume of the Earth, and the GRACE mission measures the change in mass. So these are fundamental properties that we are observing, and will continue to observe now for many, many years to come. But that's something that I'd like to throw out too is that we're not—or at least I'm not—just focused on just the hardware and just the, you know, the satellite components, but I'm also very much interested in what the satellites do and interpreting the data that they generate.
Steve McLaughlin: So you know all the things that you've talked about your expertise your interests, you know, span a huge range of things. And what I'm really curious is, you know, your path to becoming an aerospace engineer, you know, even as a kid or whether it's in high school or college. Can you talk about how you found your way to doing all these interesting things? I think there's so many young people that might be out there trying to understand. I mean, done a pretty good job I think of saying what engineers do, but how’d you find your way there?
Brian Gunter: Well I've always been sort of interested in designing things. So as an engineer your job is to build something to complete a particular task—and that's a very big umbrella. And so my particular task is the exploration of space.
You're built with basically taking a problem that needs a solution, and you build something to either solve that problem and that can also encompass programming and coding and analysis. And so I was sort of drawn—I've always sort of drawn to that. If you have some sort of unknown problem that you'd like to fix, and you know that there's a technology that maybe if you just design it right, could solve that problem. And that's always appealing to me. And then there's an additional appeal to space because there's just so much we don't know about space. We don't know about working in the space environment or the origins of life and, even, you know, every new mission that NASA sends out, especially the planetary ones, comes back with this host of just amazing images and new insights about things. And so that's also a very big draw that you have the opportunity to start tackling and answering some of these big unknown questions. So that was a big draw for me. And how I got into specifically this particular field, it started, of course, with graduate school, undergraduate and graduate. It was always—I started first as a mechanical engineer and then I transitioned into aerospace engineering because of this appeal to work with space.
But initially I thought, you know, I was going to work as a mission control guy at Johnson Space Center. That was what in most people's, I think, vision you are either going to be an astronaut or you're going to work at mission control because you see this in popular media, in the movies, and things like that. And the reality is when you get into it and I started working with the original GRACE mission when I was at University of Texas at Austin, so my advisor was the PI on the GRACE mission. And I got this other insight into, wow, there's this whole science aspect to the engineering that we do. So the science and the engineering was a really big appeal for me. And so that's what I continue doing. So I started blending more and more the remote sensing and the science and the engineering. And the more I understood more about the purpose of these missions, the more I enjoyed that.
But I also wanted to also bring my engineering knowledge to say, “A ha! I think we could do this or I think we could do this” or “If we analyzed the data this way, we'll get some new insights.”
And so it just sort of fed on that and I've built out over the years and I was able to bring that to Georgia Tech, but now realize it a little bit different way with all of the small satellite missions that we have in development.
Steve McLaughlin: You kind of touched on it—did you think you wanted to be an astronaut at one point?
Brian Gunter: I did. There was a time, and I did apply to several rounds of the astronaut program. It's extremely challenging. You got 20,000 people applying for six positions and which three will go to civilians, so if, you know, I wasn't an Air Force pilot or Navy pilot. And so it's extremely competitive. But ultimately, I tried but I wasn't disappointed, of course, because there's so many other things that so many other contributions you can make. Who knows, depending on how things go with some of these new ventures with space tourism, maybe even before my life, I'll still be in space.
Steve McLaughlin: Yeah. Is that something you think you'd like to do, if you know—right now it seems to be for billionaires and—
Brian Gunter: I’m going to hold out to make sure that—I worry less that, while the money is a factor, because like, you know, I don't have $10 million to do some of these really specialized trips. But I would like to wait for the—just to make sure that it's demonstrated to be safe, and make sure that these are reliably—before you trust your life strapping yourself onto a rocket and orbiting Earth, you want to make sure that it's going to be a safe experience.
Steve McLaughlin: Do you think, you know, in the next 20-30 years do you think that will be a possibility.
Brian Gunter: I do. I think you'll see it won't be—I think it's something that you just book up online—it won't be that popular, but I do think that in the next 20 years, you're going to see at least suborbital flights. Maybe you just get weightlessness for an hour and a half or two hours, possibly even full orbits where you're actually orbiting for maybe some days, and then you return. I think that that there are certainly companies who are pushing very hard to achieve that. And I would very much like to do that. That would be a great thing to do.
Male Speaker: Hello, Houston. the Endeavor is on station with cargo, and what a fantastic sight!
Male Speaker: Beautiful news! Romantic, isn't it?
Male Speaker: Aw, this is really profound, I’ll tell you. Fantastic!
Steve McLaughlin: You know, at the high level, it makes sense that an aerospace engineer is designing a satellite. But, like, when we get down to it and all the pieces that need to work together tens of thousands of miles, if you will, is that—what's the orbit?
Brian Gunter: About 600 kilometers.
Steve McLaughlin: 600 kilometers. OK. So to do that 600 kilometers away requires incredible skills. So can you say a little bit about—you know, this is, I think, the work of yourself and your students—can you say a little bit about the kinds of students that might make their way to your lab?
Brian Gunter: And I'll say that we rely heavily on our talented students that we've got here at Tech to do all of this work because these missions are very complex. So at any one time—and I'll throw out that at Georgia Tech in the aerospace program, we have six active satellites in development right now. And so I'm a principal investigator for three of them, RANGE is just one of them. There are colleagues within the space systems design lab, and in aerospace they manage some others. So we have six missions currently in development at different stages. Some are going to launch soon; some are going to launch in a couple of years from now.
And each one of these has upwards of 10 to 20 plus undergraduate and graduate students working on them. And they have the whole skill spectrum because you need someone who is knowledgeable in programming; you need circuit board design; you need CAD; you need structural design; you need to understand thermal properties. We have lots of mechanisms, so we have mechanical engineers, and we have computer scientists, and we have electrical engineers. We have a whole team, and I recruit from across the campus. Yes, there are certainly aerospace engineers because we need them to do the orbit analysis and the mission design, but we need everybody because, if you think about what the mission encompasses, it's everything from design to electronics to programming to science analysis—ultimately we want to do some analysis after the mission launches. There’s radio signals that we need to interpret. That's how we communicate with the satellite. So the full spectrum of skill sets need to go in to these missions.
Male Speaker: OK, loud and clear, Dave, and you’re Go for liftoff, and I assume you’ve taken your explorer hats off and put on your pilots’ hats.
Steve McLaughlin: It seems like we maybe have a mini NASA here at Georgia Tech. Can you talk about, I mean, could somebody come to Georgia Tech and kind of do the whole thing as if you think that only NASA could do?
Brian Gunter: Yes, in many ways, I would say. We have the capability here, and I think we're fairly unique or just one of a handful of universities that could even offer this, we have the ability to handle every single phase of a small satellite mission.
This includes the mission design—so the early concept work to the fabrication of it. So at Georgia Tech’s aerospace, we have a fantastic machine shop within the SSDL, the Space Systems Design Lab. Amongst the shared facilities that we have, of all the professors there, we have thermal vacuum chambers. We have vibration tables that are we use out at Georgia Tech Research Institute, so we can do all of the testing and analysis. We have the setups to do hardware in the loop testing where we’re evaluating attitude control systems and the communication systems. We have multiple ground stations. We have an S-band station and we have multiple, what are UHF radio stations, and those were used during mission operations.
So after the satellites launch, we can download the data here. All of our mission control is here at Georgia Tech. So we don't delegate any of that other than the actual launch itself to any other party. And so that's a pretty unique feature. And the number of satellite missions that we have in the works—like I mentioned, we have six active flight projects in the works—enables a student, if they have the interest, if they want to go beyond just what they learn in the classroom, the opportunity is there to come to Georgia Tech and actually get involved in a mission that is going to launch in space. And that's a pretty—I certainly didn't have that when I was an undergraduate, so I enjoy that that we have that opportunity here at Georgia Tech. And the students really enjoy it too. They love the challenge of it. They love knowing that what they are working on is going to go into space.
Male Speaker: Apollo 15-Houston, over.
Male Speaker: Hello, Houston. Endeavor’s on the way home with a burn status report for you.
Male Speaker: Roger. Sounds good. Standing by.
Steve McLaughlin: One of the questions we always ask is what makes you an uncommon engineer because I think, you know, a lot of the things that you talked about, I don't think people necessary think about it as engineers, but so, Brian, what makes you an uncommon engineer?
Brian Gunter: So I would say I'm uncommon in the sense that I am as excited as much by the science and the discovery behind some of these space missions that we work on as about the process of building the systems and the satellites that are required to achieve those goals. So I think many engineers are very content to just work on a particular subsystem, whether it's an attitude control or a propulsion system or power system, flight software or what have you, but those people tend to be relatively disconnected with the larger objective of the mission. And so I'm fortunate to have this opportunity to work on all aspects of a satellite mission. So all of these satellite missions that I've talked about—the RANGE mission, the target mission—we have taken those from a mission concepts from a PowerPoint presentation all the way to gathering data from an orbiting satellite and actually executing that. So we get the full spectrum from fabrication to testing to the analysis and interpretation. And so I'm just as excited by the science return and the data that we're going to get back by these missions, as I am in the engineering processes. So in this sense, I think I'm a little bit—I'm a little bit uncommon for most engineers in that I am a true sort of—I love the science and the engineering. I like how they interact.
Steve McLaughlin: Well, we're really lucky to have you here today to talk about your project. But I think, just as much, really lucky to have you here Georgia Tech because that kind of expertise, that kind of interest, really benefits so many students. And we just really want to thank you for today and for everything you’re doing at Georgia Tech. So thanks so much, Brian. We appreciate it.
Brian Gunter Thank you.
Steve McLaughlin: Next time on the Uncommon Engineer, we'll meet Dr. Annabelle Singer and her work on memory cognition and possible therapies for Alzheimer's disease.
Male Speaker: Apollo 15. this is Recovery, over.
Male Speaker: Apollo 15, everybody’s in good shape.
Male Speaker: We had a lot of support from a lot of people and I just like to say that we appreciate every bit of it and we could not have done the mission, we couldn't have gone one step without the support of the many, many thousands of people involved. Thank you very much.
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