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 273, hear from a NASA engineer who describes the future spacecraft design needed to transport humans between Earth and Mars. This is the fourth episode in a reboot of our series about a human mission to Mars. This episode was recorded on June 23, 2020.

Transcript

Gary Jordan (Host): Houston, we have a podcast! Welcome to the official podcast of the NASA Johnson Space Center, Episode 273, “Deep Space Transport.” 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. We’re continuing with the reboot of our series that outlines a human mission to and from the Red Planet. The fourth episode is all about what needs to be considered for spacecraft that will carry humans between Earth and Mars. This episode was recorded on June 23, 2020. Let’s get started.

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On this episode, we’ll be talking about what’s needed for the vehicle that will be doing the rendezvousing and transporting the Martian crew, the Deep Space Transport. See, the journey to Mars will be a long one, so the vehicle will need to be designed to support a crew on the nine-month ride to the Martian surface. That vehicle will need to remain in orbit around Mars while the crew explores the surface and be ready to go back for the nine-month journey. So here to go into detail about what we need to design a place to live on the way to and from Mars, or a Mars transit habitat, is Paul Kessler. He’s an aerospace engineer at Langley Research Center in Virginia. He’s working on vehicle design and mission analysis in the space mission analysis branch for the Mars Integration Group. Paul describes the challenges that come with designing such a vehicle and some of the considerations for how to tackle these challenges. So here we go: the journey to Mars and back on the deep space transport with Paul Kessler. Enjoy.

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Host: Paul Kessler, thank you so much for coming on the podcast today.

Paul Kessler: Thank you for having me.

Host: Well, this is certainly an interesting thing to be working on is, you know, I, I always like to relate Mars missions to what you see in the movies. You always see when, you know, humans are traveling between star systems and, you know, they’re going hyperspace or whatever, they’re in these big, gigantic vehicles. And of course, that’s what, I think, we all think, you know, there’s just going to be this gigantic city-sized thing that’s going to be taking us from planet to planet. But you’re part of that group that’s thinking about what that would look like if we were to take a transport from Earth to Mars, is that right?

Paul Kessler: Oh, yeah, that’s definitely it.

Host: Very cool. Well, tell us about yourself and your background, what got you to what you’re doing today?

Paul Kessler: Well, I did get a master’s degree in aerospace engineering from the University of Colorado. I’ve been working with NASA, after a few years of working with DoD (Department of Defense), I started working with NASA doing science mission work, and eventually I ended up becoming a government civil servant and I’ve been working human exploration since then within my branch. I am a part of the Mars Integration Group, doing a lot of work there, trying to understand what is the most likely scenarios and the best scenarios that we can take on for going to Mars.

Host: Well, let’s start kind of big picture here. We’re talking about, we’re talking about a vehicle that is going to transport humans to Mars. So what are some of the first things we have to think about when we’re just about to think, OK, what is this going to look like?

Paul Kessler: Well, I think the first things we think about are a lot of the first things we think about when we’re going to buy a home. We want to know how much space it’s going to have, because when we have a home we have to put things in it. We have to put our food and our supplies, we have to have maybe that extra attic just to hold any additional stuff that we want to keep in our house. But with regards to this Mars transport, it’s important to know that you have to bring everything with you. And not just those items, not just the food, and not just the food for, let’s say a few days or a week, however often you go shopping, but you have to actually bring it for the entire journey, including anything that you need to repair any items and including all the oxygen supplies that you need, because you need to be able to breathe in that thing. So the big idea is. one, is primarily space, and you have to have different working spaces. You have to have places to sleep, and you have to have places to clean up, you have to have places go to the restroom. But you also have to have places to do science and exploration and all the fun stuff, and then you have to have a chance to be able to sit down with your, your astronaut friends and have some food.

Host: A place to live, a place to work, a place to sleep. And then it sounds like a lot of the space that you’re thinking about for this thing is not only the systems that have to keep you alive and maintain the human presence in just the vehicle itself through this long, long journey, but my assumption, and correct me if I’m wrong, is a lot of backups and a lot of ways to add a little bit of redundancy because, to your point, there’s no pit stops, there’s no gas stations, there’s no restocking here when you’re talking about this kind of vehicle.

Paul Kessler: Yeah, you got it exactly right. And that’s one of the biggest drivers when we’re talking about an entire transportation system that has to also push that around. The advantage of your home when you buy it, unless of course I guess you’re taking a mobile home and you’re driving it around, really, your home is just static, you’re not having to move it around. The Earth is doing all that for you. But when you have to go through space, you got to push that around and you’re going to have to have a propulsion system that’s capable of doing that. So, really, everything that you bring has to have really a purpose, and that doesn’t just mean that it has to have a functional purpose in all cases, but it certainly has to have also a psychological purpose. But to your point, it’s, you’re talking about journeys that can last up to three years and you have to bring everything in order to fix that thing because we know that you want to make it a safe journey to and from Mars.

Host: So, with that in mind, if you’re adding all of these elements to this vehicle design that you’re thinking about, what, what are we, what can we picture in terms of size? I’m sure it’s not going to be the city-sized things that you see in science fiction, but I think the one that I think a lot of us naturally gravitate towards is the International Space Station. The size relative to, to that.

Paul Kessler: Yeah. The size to the International Space Station, we’re probably talking about maybe one-third of the size, and we’re talking about something that’s probably going to be equivalent to maybe a thousand square foot house. We’re talking about 200 to 300 cubic meters is probably the overall size that we’re going to be dealing with, at least initially. Of course, those other types of systems, I mean, those are possibilities over time. It’s just a matter of whether or not that’s the way that we want to go into the long-term future. But for now, that’s where we’re looking at.

Host: OK. So, let’s dive deep into things you got to consider. Now that, now that we have a good idea of size, let’s talk about those things that we can pack inside of it. So you already alluded to a few of those things. I think one of the primary things would be propulsion. You got to give this thing a little juice.

Paul Kessler: Yeah, that’s true. And then we also have to pack it full of not just food and water, but we also even have to pack it full of medical supplies, medicines, things like that; trash bags, things that throw away your trash; you’ve got to take care of trash in space just as much as you do at home, and you’ve got to be able to handle waste, you’ve got to be able handle scrubbing the air and taking out any sort of contamination that might be in the air. And then you also want to be able to have the oxygen necessary and filter out some of that carbon dioxide. So those are a lot of those big things, but then along with that, yeah, you have to push it with the, the propulsion system itself.

Host: That’s right. Yeah, trash is a big one. I know in the International Space Station they have, they put a lot of trash right now in the logistics module, over, attached to Node 3. They kind of put it in there for a little bit and then as cargo craft, and this is one of the benefits of being in low-Earth orbit, you got cargo craft going to and from the International Space Station quite, quite often, and you can take out the trash. You can load up those cargo vehicles with trash and take them away. Now, what sorts of considerations are we thinking about for space and for trash disposal, trash removal for a deep space transport?

Paul Kessler: Well, I think one of the biggest things is that we want to try to keep the burden on our transportation as low as possible, and part of that is that we don’t want to have to carry around a bunch of trash because that’s just going to cost more fuel. So periodically we need to make sure that we dump trash outside of the vehicle, and we have to make sure that it’s not going to hit any other parts of the vehicle and cause damage. So that’s a real key attribute to it as well.

Host: Now, OK, so you mentioned life support. There’s got to be a lot of space for the life support systems, and I don’t know if there’s, you know, any consideration to extra or maybe different redundancy, or even different technologies, for a deep space transport, based to what I’m used to on the International Space Station. Not that I’ve been there, but just familiar with it.

Paul Kessler: Right. Yeah, there’s, there’s definitely a lot of trades and analysis that’s being done at NASA with some very strong consideration for what’s been done in the past on ISS. We’re doing a lot of learning from the things that we have, and that’s a really important key. Whenever we want to do any of these bigger explorations, we don’t want to just dump all the knowledge that we’ve had and not actually leverage it. We want to leverage all the knowledge that we’re gaining, and a lot of that goes also to the ECLSS (Environmental Control and Life Support Systems) systems themselves. Now, the thing, the thing that’s distinct and different maybe from ISS is that ECLSS system, again, we want it to be a little bit more closed, and what that means is we want to try to recover more water and things like that, and we want to be able to make it more regenerative, be able to produce our own oxygen. The reason for that is that we can drive down the amount of things that we need to put on that system at the start, but just trying to get that right level of closure, that’s a real key. And there’s some people that are doing some great analysis on that front as well. And it, it is a huge burden on the entire transportation system as to this life support system, and so trying to find the right knobs to turn to get it to the right optimal levels is really, really key. And as we go through and do these analyses, I’m sure that we’re going to gain a lot more knowledge, but it is important that with any ECLSS system that we — and I’m saying ECLSS but we haven’t introduced it: the environmental control and life support system — whenever we’re, whenever we’re talking about that, it’s, it’s important to get a lot of time on those systems, that we make sure that they are reliable, that they’re really going to carry us through the whole way, because we’re talking a very long period of time on those systems, and we want them to satisfy our needs over the long duration.

Host: Yeah, it’s about that reliability, you want these systems to work over time, and then also, in terms of ECLSS systems, in terms of these environmental control systems, I mean, I know they’re hooked up to, water is a part of this, but I know even on the space station they have a toilet and that toilet breaks, and I know you want to limit how, how often that breaks. And I know, I think they’re actually gearing up the space station for an upgraded toilet to test some of the new technologies that may be on future spacecraft like these.

Paul Kessler: That’s right. That’s correct.

Host: And that’s a big deal, to make sure that that reliability is there. Even a thermal amine, that’s one of my favorites, this is a carbon dioxide scrubber and it’s, it’s a new technology that might provide extra carbon dioxide scrubbing, or even better or more efficient over longer periods of time. So all, all fantastic technologies.

Paul Kessler: Oh, yeah, and it’s paramount to get a lot of use time on those systems, especially in space. So preparing for Mars we want to make sure that we’re doing all of that, whether it be on our systems up in the Gateway or whether it be in ISS, we want to make sure that we get a lot of time on those systems to make sure that they’re fully ready for that long journey.

Host: Now, they’re going to be ready for that long journey, but they don’t have to do it themselves. They’re on this spacecraft. I know, you see it a lot in movies, even today, just a crew, they seem almost completely isolated, you know, it’s just they’re talking amongst themselves, but they do have support from Earth — even, even today on the space station they’re talking with the flight controllers on the ground all the time. So, but I think the operations might be different. So what are we looking at in terms of communication systems and then how we use that now that we’re going a little bit further away from Earth?

Paul Kessler: Yeah. I think the key there is the time, the delay time. I think you saw this in popular movies like “The Martian,” where there was a significant period of time between when something happened and when somebody knew about it, and I think we’ve seen this in a lot of other shows as well. But the thing is, is we’ve got time delay on our communications as well just because of the great distances we’re talking about from Earth. And then additionally we have situations where we could end up being in a, behind the Sun or something where our data links might be a little bit degraded, or it may be harder for us to get that info transferred back and forth between the crew. So it’s really going to be on the crew, primarily, to make sure that all their systems are running because in a critical moment, when it comes down to it, they’re going to be the first ones on the scene and they’re not going to get the help they need as quickly as they might need it, especially the closer that we get to Mars and the further away we are from Earth.

Host: Yeah, a little bit of autonomy, and I’m sure that’s going to come with a lot of training as well.

Paul Kessler: Oh, definitely. And I know that NASA has already looked at ideas of using virtual reality to do training, even doing training on orbit. I believe they’re doing a lot of that also on ISS.

Host: Now, in terms of the materials, you know, are we going to see something maybe made out of a lot of the same materials that we see on the International Space Station; I’ve seen some expandable technology demonstrations in the past. What are we looking at for what this thing is made out of?

Paul Kessler: Well, I think it’s still a little bit up in the air about where NASA wants to go with the type of systems that it’s going to choose, but we have some great contractors that we’re working with on a contract that are doing some of that development and telling us where the right, the right systems are, what they look like and what we should be utilizing. We have, we have systems that include some of these inflatable structures that you talk about. Now, a lot of times when people think about inflatable, they might think of a balloon, but these inflatable structures are a lot firmer. They, they feel a lot more like hard structures when they’re fully expanded than they would maybe a balloon. And we’ve looked at those because the advantage to that as well could be that you could get more volume for less mass. Now, it’s a newer technology, so there, there is some learning to have to do on that, so the way that we have to go in the future is to really try to flesh out those structures and make sure that they’re really ready for the long duration and whether or not we can really rely on them. And so we’re really trying to buy that down with a lot of these contracts, is try to understand what those would look like and try to buy down the risks by doing more testing and understanding of those systems. And then at the same time we’re leaving it open to the ideas that would utilize systems that are a lot like ISS, but, you know, with that, there might also be a change in the way that you would want to use those systems in terms of if you think that it makes more sense to put things at Mars beforehand, or whatever. So we’re leaving a lot of that trade space open, and we’ll be coming to more conclusions as time goes on, but I think we’re making a lot of headway right now with the wonderful contractors that we’ve been working with so far.

Host: Wonderful. Now, I know that the journey itself is, is a little bit different from what we’re used to with the International Space Station. I know I keep going to it, but in terms of just a habitat to, where people live in space, that’s naturally where I gravitate towards. But low-Earth orbit is a little bit different from deep space. You got a little bit of protection from the Earth. In fact, the space station is going on the other side of Earth relative to the Sun. So naturally, things like I think about are the radiation environment on the journey to Mars, the thermal environment on the journey to Mars. What are these considerations that the deep space transport is going to have to deal with for the environment on the way there?

Paul Kessler: Yeah. I mean, I think you’ve, I think you’ve touched on it a lot, is the radiation, when we’re at ISS, is not necessarily going to be as bad because we’ve got the magnetic field around the Earth that’s really deflecting a lot of that radiation. But as we go further out and we venture out there, we’re going to have to deal with galactic cosmic radiation that’s coming from other galaxies and supernovas and stuff like that. And then we’re also going to have to deal with it a little bit different type of radiation, and that’s the solar radiation that we get. And in those instances, what we do is we try to mitigate it with systems that, where we can have a safe place to hunker down if there’s a storm that comes about, and we have abilities to detect those kind of things and that’s what we have to do during those situations is get behind a lot of things and make sure that we’re safe from that radiation. But that’s definitely a big-hitter item. Another thing, like you talked about, was the thermal, especially if we ever think about going away from, from Earth, going further out into the solar system, we know that the thermal characteristics are going to be quite different the further you are from the Sun, or even if you’re getting much, much closer to the Sun, if you decide to swing by Venus or something like that, you’re going to have to really reject a lot of additional heat in those cases. So those are really critical because we want to make sure that our astronauts in those situations have a shirt-sleeve environment that our systems survive, that our systems are doing well in terms of thermally. And then, and then I think another thing is that we have to consider the fact that gravity also, or the lack thereof in this case, is, is also something that’s going to affect the human body. So, in that vein, we also have to make sure that we have exercise equipment and we try to fight back against the lack of gravity that we’re doing on the way to and from Mars because that’s the longest part of the journey.

Host: Yeah, we’ve, you know, we’re talking a lot about what could be onboard and things you have to think about to go onboard of a deep space transport, but you were talking about swinging by Venus and that brings up another point is, when you’re designing this spacecraft that’s going to take people to Mars, what is, what is the profile that you’re looking at? In terms of a mission profile, let’s say, let’s say we have the deep space transport, what, what is this looking like? You know, is it as simple as people just hop on board of a deep space transport, it takes off from Earth and heads, heads over to Mars? I’m sure it’s a little bit more complicated than that.

Paul Kessler: Yeah. Right now, we’re, we’re looking at, as far as our departure and arrival, we’re looking at going from an Earth orbit that’s really, really big, that goes out all the way to the Moon itself, to the Moon’s orbit itself, and that we would get the crew to come from Earth to rendezvous with the transportation system, and then they would transfer on and then they would leave from there to go to Mars. Now, the advantage to something like that is that we have a lot of the gravitational capability that the Earth gives us that we can use to, to leverage to get us a little bit more velocity. Then we could head to Mars. And when we come back we would, we would, right now, we’re looking at entering back into that, that large orbit — we call it a HEO orbit, or a highly-elliptical orbit, or a high-Earth orbit. And then we could get the crew off of there at the end of that mission and then they can, that system would go autonomously back to the NRHO. So, the NRHO is a near-rectilinear halo orbit; it’s a fancy term for, there’s an orbit around a point in space that’s really near the Moon and it’s just a really nice, a really nice orbit for us in terms of its stability and not having to do a lot of boosting, and we could go there — and we also have good access, by the way, to the lunar surface, which is all a part of that whole Artemis mission as well, where that orbit is also where the Gateway is. So, at the Gateway, we would put the habitat itself and we would prepare it, we would outfit it, we would test out a lot of its systems, before we go on to those long journeys and before those transportation systems themselves even arrive.

Host: Excellent. OK. So, I’m sure a lot of things being put into Gateway, you’re thinking a little bit ahead as well. Not only are you, you want this Gateway for the Artemis missions as sort of an outpost in this near-rectilinear halo orbit, but it seems like a good place from a trajectory standpoint to get to Mars.

Paul Kessler: Yeah, it’s a good point to stage everything. So, what I mean by that is that we can get a lot of stuff up to this, this particular orbit and we can put a lot of things there without having to try to do a lot of reboosting or anything like that, and therefore, we can save ourselves on a lot of propellent. Then we can take, go from there to that higher-Earth orbit before we leave, and we can save ourselves a lot of fuel in the end. I think I’ve heard as far as 20% more mass, or something like that, additional, if you go to the NRHO.

Host: So, in terms of the vehicle itself, naturally what comes to my mind is, again, the International Space Station but this, this vehicle is continuously occupied. You got people on it, now coming up on 20 years continuously. So, you have folks on board to fix things if they break and attend to things as needed, on top of all the experiments that they do, is, but would this deep space transport be able to be unoccupied for periods of time, waiting there for a crew to arrive and take it to Mars?

Paul Kessler: Yeah, it’s going to have to be. At least as far as we’re looking at now, it’s going to be that way. So we will have to have systems that can help maintain the habitat itself. We’ve got to have a lot of autonomy there. We’ve got to have a lot of capability to do things from the ground while we’re outfitting or between missions, and between Artemis missions even, while we’re preparing this vehicle to go to Mars.

Host: Now, we’re talking a lot close to Earth, you know, we’re going to do all these things close to Earth, and then, here we go, here we go to Mars. So what does, what does that journey look like, in terms of length of time and in terms of what you imagine the astronauts to be doing during that length of time until they actually arrive to Mars?

Paul Kessler: Oh, very, very good questions.

Host: Yeah.

Paul Kessler: We have, we have different trajectories that we’re looking at now that are still within our trade space, which is what we’re trying to analyze, and some of those can be as low as 700-ish days of an entire round trip, with maybe a short stay on the Mars surface, about 30 days is what we’re talking about, or we could have even longer missions that last about three years. The advantages of each side are, with the shorter missions, naturally humans are in space a shorter amount of time, which is better for the body, and it allows us to do maybe shorter missions on the Mars surface. Now with the longer missions the advantage is being on the surface of Mars longer, but at the same time we save a lot on propellent and having to have large systems to push us all the way to and from Mars. Now, we’re looking at both of those options. We’re looking at, within this trade space, about what makes the most sense based off of the risks that NASA, the agency, wants to take, and what sort of things that we want to accomplish. Now, you asked a second question, which was, what would the astronauts do on these long journeys: well, I think they would do a little bit of things that we would probably do on a very long journey, and I don’t think it would be singing “The Wheels on the Bus Go Round and Round” or anything like that, but they might play some video games or have a good time, just have some time to get to know each other, and also doing a lot of maintenance of systems because that’s one thing that we spend a lot of time doing already; we want to make sure that we maintain our systems on ISS, we want to make sure to do the same thing in transit. Then you’d be doing a lot of experiments, and you might even be doing a lot of photography of different things. If you pass by a special type planetary body, something like if you did a fly-by of Venus, it’d be kind of neat to take some video, some pictures and things like that. So you can imagine that humans would be doing a lot of those things, along with the day-to-day items like their work, their workout, which is part of their work, just trying to keep their body from deteriorating on any long trips, but they would also have those times to eat and have fun.

Host: And I know keeping busy is, is a big part of even mental health. We’ve talked with some psychologists here on the podcast recently and, you know, just when you imagine those space missions, again, going back to those movies, they, they always kind of look a little bit bored, like they’re just kind of waiting, you know, to arrive there. But the truth is, they got a lot to do, based on what you’re saying: they have exercise, they have eating, they got photography, they got science. I mean, they’re going to, they’re going to have a lot of ways to fill their time on the journey over to Mars.

Paul Kessler: Definitely, yeah. You want to make sure that they are mentally well as well as physically well. So, it’s important that we do, keep them busy doing really good work and something that they find enjoyable as well. So we don’t want them to just do, you know, 12-hour days of working; we want them to actually have opportunities to decompress, to have some time just making friendships and building on their friendships, or, or even just trying to have some fun time, just playing some games or whatever it might be.

Host: Yeah, getting together and singing “99 Bottles of Tang on the Wall.”

Paul Kessler: [Laughter] That’s right. Good one.

Host: [Laughter] So, there’s a lot, now, let’s go to Mars, right? So, we’re talking about the journey on the way to Mars; now let’s say you’re arriving. So, I’m sure getting there you got to go pretty fast, so at some point you got to slow down. Now what are you doing? Is this thing going to go into a Mars orbit? That’s what I’m thinking.

Paul Kessler: Yeah, that’s right. So, we speed up, but as we’re getting there we’re going to have to slow ourselves down, start trying to match the speed of the planet itself, such that we can start falling into an actual orbit. Now, when we’re in that orbit we’re going to be doing a lot of preparations for a mission to the surface, and part of that is going to be rendezvousing and docking with the actual lander that would be used to go to the surface. And as we’re doing that and as we’re preparing for those kind of things, you know, those are the critical times because if, if anything were to not work out exactly right we want to be able to have contingencies available, we want to be able to have additional, additional fuel and other things in order to continue to try to do more dockings with that so that we can continue to move on and have a successful mission itself and not have to abandon anything that we’re doing there. But that would be the biggest thing, is that we have to rendezvous and dock with our, with our lander.

Host: See, that’s huge. There’s a lot of, there’s a lot of staging involved before this transport even, even starts heading to Mars. One of them being this lander in a very…

Paul Kessler: Yep.

Host:…in a predictable orbit to meet up with. So that, so that is part of it, is the lander itself would not be part of this deep space transport vehicle: you’re talking about a rendezvous in Mars orbit.

Paul Kessler: That’s right. So, things would have to be sent prior to us getting there, and those things would have to be sent on a previous opportunity, two and a half-ish years prior to us leaving, or the astronauts leaving. And while those are there we need to check out those systems from the ground before we even send the crew to make sure that they are where they’re going to, need to be for the crew when they get there. There’s no point in leaving Earth if things aren’t checking out appropriately. But so, we would do those kind of checkouts before they leave so that when they arrive they do know that their, their chances of rendezvousing and doing all those things are really, really high and it’s a safe journey.

Host: Now, what else do they need to stage? They got the lander in orbit; what else has to be ready for them before the transport gets to Mars?

Paul Kessler: Yeah. So you have to have a lander, but you also have to have something that is going to take the crew back from the surface to the actual habitat itself as a separate thing because it’s got to have its own fuel, and trying to figure out a way to try to put that all in one lander is, is a real challenge. Now, there may be a point in time in the future that we might be able to do all of that, but for the meantime we would have to have something like that that would get them back to the actual habitat. Now if you’re going to do a longer stay, you’re going to have to have a lot more systems on the surface, such as larger habitats and things like that.

Host: So yeah, so that’s a big thing. This lander that they’re going to be rendezvousing with in Mars orbit, this is a separate vehicle from an ascent vehicle on, on Mars. You said combining them would be, would be a challenge. So now we’re talking we got a transport vehicle, we got a landing vehicle, and we got an ascent vehicle, and then to your point, depending on the mission profile, if it is longer, they’re going to need a place to live.

Paul Kessler: That’s right. That’s right. And you could look at anything from having some sort of rover that they go down on, where they can actually drive around the surface of Mars and then also make it over to the ascent vehicle itself, or you could have static habitats themselves that they would, they would go in. We’re trying to do a lot of our practicing on Artemis missions for doing those types of things on Mars. So, using Artemis as the backbone for understanding what it would look like going to Mars is really, really helpful. Now, there will be some differences, but all the overlap that we can, can get is really, really helpful because as you can imagine, going to Mars is really, really hard and it’s expensive. If we were just starting from scratch, then it would be a really difficult thing to really achieve. So we’re just trying to fulfill, fill all of our knowledge gaps that we might have by developing these technologies and using them also on Artemis missions and other things.

Host: So, what are some of those, what are some of those other pros to, to doing this at the Moon first? Why do this, why practice at the Moon?

Paul Kessler: Well, I mean, we’re very close to home so it’s a lot easier for us to abort the mission and head back to either the Gateway itself, because it will be near the Moon, or to head back to Earth itself. And the other advantage of it is that we can see how, how they handle longer and longer durations while we’re near the Moon, with that same capability to do the abort. So I think that’s the real key there.

Host: Oh, I see. You can scale it up. You can do shorter, kind of like what you’re saying with Mars, where you have the option of shorter missions and longer missions; if you’re talking about an Artemis mission, you could start shorter and then the whole point of Artemis here is to build a sustainable presence on the Moon, so as you continue to go back, just like Apollo, you could stay for longer and longer and longer. Now we’re talking, you know, way longer than Apollo, but, but that would be a huge help to understanding how to live and work for long periods of time because that is the difference. To your point, that is the difference, is Mars is, you would have to do it for a really, really, really long time.

Paul Kessler: That’s right. You got it exactly right.

Host: Yeah. Unbelievable. So, tell me about some of these — you were talking about contracts a little earlier on, you know, we’re trying to investigate that with some, with some contracts, we got people looking at this, that and the other thing; what are those things that we, that are right now that people are investigating for a deep space transport and a Mars mission?

Paul Kessler: So, we have this contract mechanism called NextSTEP, (Next Space Technologies for Exploration Partnerships) and it has different, through that contract mechanism we’ve also been looking at getting contractors that have been bidding out for the, the Human Landing System for the Artemis mission, but in an earlier part of that contract there’s this habitation that is meant for space. It can be meant for surfaces, it can also be meant for out in space itself as a transport vehicle, and we have a few contractors working on that, that are looking at systems that would be used for this transportation, this Mars transportation habitat, and then we have other things that they’re looking at for the lunar surface itself. And what they’re doing is they’re taking a lot of their expertise and their knowledge in building habitats and they’re doing some testing and some design, and they’re using a lot of the, the protocols or ground rules and assumptions is what we call them, for doing a lot of that design, saying here’s kind of the restrictions on what we should be looking at, so that they’re looking at the right stuff, without actually getting down into the detailed requirements. So it’s really early, prior to it becoming a full project yet, but it’s an opportunity that avails us this ability to have more studies from the contractor’s side, from their experience that they bring to bear, to, to NASA, where we can learn some things about what this system might actually look like. And so those contractors are, again, like I said before, they’re building inflatable types of habitats, they’re building modular-type habitats that they would put together, and then they’re showing us how they would put them up and what kind of operations they would do on them, what kind of risks they can see and identify, and what those things might look like in terms of costs and schedule, will it meet the cost and schedules that we’re trying to fit within.

Host: Yeah. To your point, you know, you don’t want to start writing requirements right now because your, your goal right now is to see what it would look like, and you don’t want to restrict very innovative ideas on what it could look like. So, just, here’s, here’s what we absolutely need, and then people come up with different solutions to fit those needs. So there’s this, there’s this wide range of ideas and it helps you to pick down the best one, and maybe people can come up with ideas that, that maybe people haven’t thought of before.

Paul Kessler: That’s an excellent point. I think that’s exactly what the whole purpose of the NextSTEP contract is…

Host: Yeah.

Paul Kessler:…is we want to see innovative ideas, we want to look at contractors and trust them as experts, and then we want to look at their concepts against what our NASA experts are saying and against our own reference systems that we design internally to say, does this, does this work, is there something missing, are there new ideas that are being brought to bear here that we could utilize in the future? And so, we’ve learned a lot of amazing things from these, these wonderful contractors that we’ve been working with, and I look forward to seeing even some more innovations that they can come up with.

Host: Well, let’s talk about the range of ideas and people that are involved, involved in this. You know, and I think naturally when you’re thinking about building a deep space transport, people think that you have to be a rocket scientist to do anything, but I feel like there’s a wider set of skills that are needed and a lot of help from all of these different people to really put this thing together. So, what, who, who is helping out with, with designing this?

Paul Kessler: Well, I would say people like me, our systems analysts, that are looking at this as an integrated picture, so it’s one thing, you could do systems analysis, which is really to assess what the overall goal of your system is and whether or not it’s going to achieve that, whether it’s going to be feasible or not, and this is to help those decision makers understand those systems, to say this is the route I want to take based off of the risk posture that I want to take, or the costs or schedule, or things like that. And so system [analysts] like me, we might look at it from a side of, like people within my office might look at it from, in terms of designing some trajectories that might be used that are going to optimally use propellent. Other people might design actual vehicles, like, like I’m doing, working with this, this Mars transit habitat to do the actual initial design that we can compare against contractors and look at. But we also want to look at the overall integrated picture, and I think it’s really, really key — and it could be lost in the weeds, especially when you talk about earlier, like, if we go to requirements right away we’re going to stifle innovation. The same thing is that if we go to requirements too early, what ends up happening is we paint ourselves into a corner and now we’re trying to get something to work for an overall, bigger plan that’s not going to work as well as we want it to. So when I say campaign, what I’m talking about is, if you were to think of each, each element, everything that we’re going to put into space to get this overall thing accomplished. Let’s say I want to go to Mars in, somewhere in the 2030s and I want to land on the surface: what all is involved, how do I get it there, what does it look like, how do I ensure that it’s got the best chance, what’s the feasibility, what’s the risk, what’s the cost to all of those kind of things? Those are important key parameters to helping our decision makers really know which direction we should be taking. So you want to look at it in an integrated level because if you, if you, let’s say, build a lander or an ascent vehicle that, let’s say, and this is a simple example, doesn’t have the same docking system that you have on the vehicle that’s showing up, they’re not going to be able to dock, and that’s a problem. So we want to make sure that we are taking into consideration not just the individual level of, let’s say, the habitat or the propulsion system, but how does that propulsion system match up to the habitat, how does that habitat match up to this other system, and how do we keep it where it needs to be so that we can get to it.

Host: Yeah, those, it’s all those, it’s, “the devil’s in the details,” as they say. You know, you talk about building a deep space transport but it’s those little things that can sometimes make or break a mission, so thinking about them ahead of time is absolutely critical. Going forward to Artemis here, you know, we’re talking about a transport to Mars and there’s a lot of considerations for that distance, for that length of time that you have to think about; but what excites you about Artemis here, because Artemis is, yeah, like you said, a little bit closer to home and we’re trying to go quickly, we’re trying to go soon, so what excites you about things we can work on and learn during the Artemis program?

Paul Kessler: Well, I, I think it’s, it’s really an exciting time to be in right now. I mean, our ability to not only explore just one destination but then to really position ourselves to explore that second or third or fourth destination, wherever that might be, including Mars, is, it’s really, really exciting. I mean, this is, it’s been a long time since, I think, the United States and the world have gotten to have such inspirational motivation to, to explore. I mean, we have that real desire in us to understand the questions, the answers to the question why, and to understand about things. And we want to know, even just for the sake of knowing, but we also want to experience. I mean, life is about a lot of experience, and wonderful, beautiful experiences, and we want those experiences to reach the highest possible heights. Well, what’s higher than going to space, right? In the Artemis mission you get to go to space and then you get to go and land on the Moon. I mean, that’s an amazing thing, and how can you not be excited about it? It’s the new explorers, the new generation that’s going to carry us into the future. You know, I was once told, or I think read somewhere that, you know, if you’re going to live, go on living, right? And that’s what we got to do, we got to get out there and live. We got to make life worth living, and to make life worth living one of those things is we can’t, we can’t just live off of just basic necessities. We’ve got to experience life in its overall grandiose beauty, and I think that’s what’s so exciting about this exploration that we’re going to be doing to Mars, through Artemis, and doing that quickly. We’re ambitious, we’re trying to push, push the envelope, push forward, and try to do that. I mean, it’s inspirational, right? We’ve, we’ve seen a lot of these things. I think a lot of people have grown up, especially nowadays, where you see all these superhero movies or you see “Star Wars” or you see “Star Trek” or you see all these, these wonderful movies that are inspirational to so many, and they’re like, “but why aren’t we doing that,” right? We want to live that life. We want to, we want to experience life more, and I think this is an opportunity to do that.

Host: Paul, that’s beautifully said. That is, it is truly an exciting time and, you know, I’m looking forward to being a part of a generation of, where I can say that I, you know, see moonwalkers, I see people walking on the Moon, and then hopefully people taking those first steps on the Martian surface. Man, what an exciting time it would be to be alive during that.

Paul Kessler: Oh, yeah.

Host: Yeah. Absolutely. Paul, I appreciate your time going through the, the detailed description of what we’re looking for, for a deep space transport. I can’t wait to see some of the designs and ways this is going to be put together and to get people on it, on the way to Mars. I appreciate all you do. Thanks, Paul.

Paul Kessler: Thank you. I, I appreciate the opportunity to, to tell you and your listeners all about it.

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Host: Hey, thanks for sticking around. Hope you’re enjoying our Mars series. You can go to NASA.gov/podcasts to check out more of our Mars episodes, that’s where we are, and you can listen to any of our episodes in no particular order. You can also check out many of the other podcasts we have across the whole agency. If you want to talk to us, we’re on the NASA Johnson Space Center pages of Facebook, Twitter, and Instagram; use the hashtag #AskNASA on your favorite platform to submit an idea for the show, and make sure to mention it is for us at Houston We Have a Podcast. Thanks to Will Flato, Pat Ryan, Heidi Lavelle, Belinda Pulido, and Jaden Jennings for their part in the podcast as always. Shoutout to former podcast team members Alex Perryman, Norah Moran, and Jennifer Hernandez for their help in the original episode. The episode originally aired August 7, 2020, as Episode 156. Thanks again to Paul Kessler for taking the time to come on the show. Next week for Episode 5 in our Mars series we chat with Chel Stromgren about packing for Mars. Spoiler alert, it’s slightly more complicated than packing for a cross-country road trip. Give us a rating and feedback on whatever platform you’re listening to us on and tell us how we did. We’ll be back next week.