If you’re fascinated by the idea of humans traveling through space and curious about how that all works, you’ve come to the right place.

“Houston We Have a Podcast” is the official podcast of the NASA Johnson Space Center from Houston, Texas, home for NASA’s astronauts and Mission Control Center. Listen to the brightest minds of America’s space agency – astronauts, engineers, scientists and program leaders – discuss exciting topics in engineering, science and technology, sharing their personal stories and expertise on every aspect of human spaceflight. Learn more about how the work being done will help send humans forward to the Moon and on to Mars in the Artemis program.

On Episode 160, Chel Stromgren, chief scientist of Binera, Inc. and part of NASA’s Mars Integration Group, lays out the complexities and the innovative strategies needed to pack for a human mission to Mars on this fifth episode of our Mars Monthly series, where we drop a new episode about a human mission to Mars on the first Friday of every month. This episode was recorded on July 10, 2020.

Check out the Houston, We Have a Podcast Mars Page for more Mars Monthly episodes.

Transcript

Gary Jordan (Host): Houston, we have a podcast. Welcome to the official podcast of the NASA Johnson Space Center, Episode 160, “Packing for Mars.” I’m Gary Jordan, and I’ll be your host today. On this podcast, we bring in the experts, scientists, engineers, astronauts all to let you know what’s going on in the world of human spaceflight. Our Mars Monthly series continues. Last month we chatted with Paul Kessler who described the deep space transport, or the Mars transit habitat, a little bit about what that may look like, and its important segments. On this episode, we’ll be focusing on what we need to pack inside of that transport. They’ll of course need things that you pack on a normal road trip, food, water, clothes, but this road trip will be a doozy. You’ll need to bring breathable air, running on super reliable systems, and enough spare parts to carry you through a multiyear mission, because there’s nothing that you can forget. Once you leave for Mars, there’s no turning around and no resupply vehicles to send afterward. So here to go into detail on what to pack for Mars is Chel Stromgren, Chief Scientist of Binera Incorporated and part of NASA’s Mars Integration Group. If you ever need help packing for a road trip, this is the guy you’ll want to call. Pack your bags and don’t forget anything. We’re going to Mars with Chel Stromgren. Enjoy.

[ Music]

Host: Chel Stromgren, thank you so much for coming on Houston We Have a Podcast today.

Chel Stromgren: Oh, good morning. Thank you.

Host: Alright. Very glad that you can come on. I’m very interested in this topic. I feel like if there was anyone that could help me pack for a road trip, it would be you.

Chel Stromgren: Yep, we’ve got a lot of experience planning for packing.

Host: [Laughter] Well, I’ll tell you, it’s got to take some background to get to this point where they’re going to you and trusting you to pack for Mars and think about all the different things that you’re going to need on this journey. Tell me a little bit about yourself, your background, your education, and some of the stuff you’ve done for NASA.

Chel Stromgren: Sure. Sure. I got to NASA kind of in an unusual route. Undergraduate, I majored in and got my degree in naval architecture and marine engineering. So, similar kind of challenges. You know, I was doing ship design, designing large cruise ships, navy ships, and I did that for a few years. Then I went back to graduate school at MIT and shifted a little bit into an area called systems management, which was really focusing on, you know, how do we take these complex systems like ships or spacecraft, how do we manage them in the most efficient way. How do we run them? How do we operate them? And a big part of that was looking at the logistics required. What are all the supplies we need? What are the spare parts? You know, how do we repair them over time to maximize the value? So, after doing that, when I got out, I was working for a number of customers, but NASA was obviously, you know, had a huge need in this area to plan space missions. So, I slowly got more and more involved with NASA and now, you know, I work as part of a team that really does, you know, all the logistics planning for these long-range missions.

Host: Alright. Well, tell me a little bit about what goes into that. When you’re planning for a long duration mission, what are those key things you have to really bring in the front of your mind?

Chel Stromgren: Sure. Maybe I can use an analogy here. So, imagine you were going to take a road trip and it was going to be a three-year road trip in your car, but here’s the catch, you can’t stop along the way. You can’t stop at a gas station. You can’t stop at a Target. You can’t stop at a hotel. You can’t even stop at an auto parts store. So, everything you’re going to possibly need for that entire three years you’ve got to bring with you at the start. So that’s all the food you’re going to eat, all the water you’re going to drink, all the clothes you’re going to wear, all the toothpaste you’re going to use, and everything you need to keep the car running. Right? So, any spare parts, any tools, that all has to be packed. And then anything you’re going to do along the way, any science, any exploration, any cameras. So, my job is essentially to figure out how do we do that? What do we need to pack in that car to start the road trip so we can complete the entire trip without any problems? And then to do that, of course, because this is space travel, with as little mass and volume as possible.

Host: [Laughs] Just that added little complexity there, huh?

Chel Stromgren: [Chuckles] Right. Exactly.

Host: Alright. So, tell me about some of those challenges, right? So obviously that’s a challenge just in and of itself. I’m trying to image what that vehicle would look like on the road if I had to bring all of that stuff for three years. And I’ve got to say, if you’re talking about bringing something small and light, I mean, that’s a very difficult challenge because naturally I’m thinking something real big that’s going to fit all of those things.

Chel Stromgren: Right. And that probably is the biggest challenge, because you know one way to approach this is just to be really conservative, right? You know, just pack a whole bunch of food to make sure we have enough, but as you said, you know, in a spacecraft, that’s not really possible, especially when you’re going to Mars, right? You’ve probably, with other people, heard this term, “gear ratio,” right? The gear ratio, which is how much propellant we need, you know, versus how much mass we have to push is really high. So, it’s really imperative that we keep the mass down. So, we can’t just be conservative. We can’t just say, “Yeah, we’ll pack so much food, they’ll never run out.” Instead what we have to do is we have to look at a whole lot of historic data. You know, one of the huge advantages we have in my area is, you know, we have the International Space Station. And the International Space Station is probably the greatest possible laboratory I could hope for because, you know, we’re doing it all the time. So, we can look in detail at how food is consumed aboard the International Space Station, what the variability is, you know, for different astronauts. And then working with others, like the NASA food lab, we can look at, you know, different levels of nutrition, what’s required, what’s the lifetime of different food items. So, we bring all that data together and we can actually build a probabilistic model of consumption rates, of, you know, different nutrition needs, lifetimes. And that lets us plan out, you know, in detail exactly what we’d need to bring in terms of food. And then we do similar things, you know, for all these other areas, for all these other packing, you know, clothing, hygiene supplies. And then, you know, because it’s a spacecraft, even things as simple as water and oxygen, you know, we have to bring those with us. So, all those things get analyzed in detail. We build these models and that’s really what allows us to kind of find that sweet spot of enough that we’re going to be safe and healthy, but not so much that we’re going to kill the mission.

Host: This is perfect. You’re describing all these different considerations we have to think about and the ISS as a perfect model for thinking about that. But let’s go into some of the challenges. What is this challenge that’s presented in front of us for getting to Mars? I’m talking about the duration of the mission, the distance of the mission. What are the things we have to think about for a Mars mission?

Chel Stromgren: Yeah. And really the biggest challenge there is how long we’re away without any kind of resupply. So, you know, the ISS, although it’s been flying for over 20 years, we’ve never gone more than 120 days without resupply. We fly these cargo vehicles to ISS all the time, Cygnus and Dragon. So, you know, if we find out we’re short of something on ISS, you know, it’s never more than 120 days or usually less that we have to go without it. You know, the real challenge for Mars is, you know, some of these missions we’re looking at can be up to three years long. So, you know, it’s just that shear duration that makes it so difficult. And I’ll give you an example, one of the biggest challenges we have is spare parts for the spacecraft. You know, the spacecraft is really complex and there’s lots of things that can break. And although we understand the reliability of different things, it’s really, really difficult to predict exactly what may break on the mission, right? It’s kind of a probabilistic type of situation. So, we have to be able to figure out, you know, based upon the projected reliability, which spares we might need to bring to cover that entire three-year period. Because again, I can’t stop at the auto parts store along the way. So just that shear duration and the isolation from Earth makes it absolutely imperative that everything is loaded up front. And it takes a lot of complicated analysis to even begin to try to figure that out and a lot of data. Again, you know, ISS is really key here. And, you know, for us it really benefits us to look at systems that are very close to ISS in nature so that we can take advantage of that 20 plus years of operational data to understand, you know, well how often do different parts fail. You know, what was the result of those failures? What was the best way to fix them during the mission?

Host: So that kind of informs when you’re thinking about spare parts, it informs what that’s going to look like, what the Mars mission is going to look like with the parts you need and then the number and the types of spare parts that you also have to consider when you’re thinking about a Mars mission.

Chel Stromgren: Correct.

Host: Yeah.

Chel Stromgren: And then we have to get really creative, right? Because again, you know, we can’t just bring a warehouse full of spare parts.

Host: Right.

Chel Stromgren: So, we have to start to get really smart in how we do things. And one of the big differences I’m sure we’re going to see on a Mars mission is the astronauts are going to have to repair equipment down at a lower level. You know, in ISS, although you know obviously, spaceflight even to LEO [Low-Earth Orbit] is expensive, compared to going to Mars, it’s relatively cheap. You know, most of the time we have the space shuttle and now we have other vehicles. So, in ISS, because they wanted to maximize the amount of time available for science, they repair things at a very high level. If something failed, they would essentially replace the entire box, right, no matter what failed within it. That’s not an approach that’s going to work with Mars because the mass of all those giant spares would be too high. So, the astronauts are going to have to start repairing things at a much lower level. They’re going to have to start tearing down equipment. Like instead of replacing the entire dishwasher, they’re going to have to go in and find the one part that failed and fix that part because, you know, from a mass perspective that’s going to be way more efficient. But it’s going to put way more of a burden on the astronauts because they’re going to have to become, you know, essentially repairmen in space.

Host: I was going to say, for International Space Station training, they’ve forgone a lot of that system level maintenance that we saw a lot in the Gemini days and Mercury days, even Apollo days of fixing those tiny little components, knowing the guts of the spacecraft and some of those systems from the inside out. Space station training has evolved to really, like you’re saying, just basic stuff. You know, if this breaks, swap this part. You’ve got this thing over here. And they try to make it, as you’re saying, as easy as possible because the mission on the space station right now is science.

Chel Stromgren: Correct. To the point where they put quick disconnects on things. Right?

Host: Yes.

Chel Stromgren: They want to make it so easy that they’ll set up five quick disconnects. You’re absolutely right. The astronauts, because they shouldn’t on ISS, they don’t have to know how a specific piece of equipment works. They have to know the five plugs and disconnects they have to undo to replace that entire unit. Then it’ll get disposed of and they’ll just install a whole new unit. But you’re absolutely right, they astronauts who go to Mars are going to have to have an intimate knowledge of those systems, so they can go in and replace an individual pump or an individual valve if it fails.

Host: Wow. Now in terms of the supply, you know, we’re talking about a Mars mission and the analogy is so perfect of thinking about a car packed with three years of stuff. But I’m thinking about a Mars mission and it’s maybe not as closed as that. I’m trying to think of opportunities where there might be little stations or places where you can resupply stuff. I’m thinking you could stage stuff in Mars’ orbit. You can stage stuff on the surface of Mars. All ahead of time so maybe you can pick it up on the way and you don’t need to necessarily bring your car or pack that Mars transit vehicle, you don’t have to pack it full of three years of stuff. You can stage stuff ahead of time. Is that a consideration?

Chel Stromgren: Yeah. So, we’re definitely looking at that. Let’s talk about the surface first.

Host: Sure.

Chel Stromgren: Because you’re absolutely right. I mean, obviously, you know, everything that goes to the surface, we’re going to preposition. Right? It wouldn’t make any sense for the astronauts who are traveling to Mars to take everything they need on the surface with them. So almost certainly, you know, there will be landers that go down to the surface that precede the crew that will carry the things they need on the surface. And that’s all the stuff we’ve talked about, the food, the water, the, you know, the EVA suits. And it’ll also include all the stuff they want to use to explore the surface, the science, the rovers, things like that. So, you’re absolutely right. On the surface we will almost certainly preposition everything we need there. Although that does come with its own challenges, right? Because now you’re talking about sending things out years ahead of time, you know, and making sure that they have a very high reliability of working for the first time the humans touch them after three years of traveling through space. But going back to the other analogy, so for the in-space duration of the humans traveling to Mars and could we position things like in Mars’ orbit to be picked up? And certainly, that’s an option and it would have huge advantages in terms of propulsion. Right? Because we could send all that stuff out on a nice slow transit ahead of time, low energy, you know, it would cut down on the prop requirements. And then we could minimize, you know, the mass of that crewed vehicle, which we want to go as fast as possible. But there are challenges there certainly from a risk standpoint because now if you think about it, I’m heading out to Mars and if anything happens to that cache, if for some reason I can’t dock with that cache, now I don’t have enough food to get home. So, you know, we are looking at those options, but it is a pretty significant risk trade to try to take that. You know, even if a case happened where we couldn’t break into Mars’ orbit, if we have all those supplies with us, there are often abort trajectories we can take. Right? We can alter the trajectory, head back to Earth, potentially without even going into Mars’ orbit. But now if all that stuff is prepositioned, now it’s a mission critical step that I have to be able to stop, dock, and get all that stuff, or I’m not coming home.

Host: Yeah. That is a big risk that you’re introducing now. Yeah, you’re right.

Chel Stromgren: Yeah.

Host: Anything can fail. That far away, anything could happen.

Chel Stromgren: Yep.

Host: And that’s something you really have to consider for a Mars mission. What happens if, you know, you can’t dock, or something happens where it doesn’t line up the right way or you know? I’m trying to think of every possible scenario and yeah. That almost makes you want to, if you were packing this vehicle, pack it with just enough where if you couldn’t dock for whatever reason, you can get home on rations maybe. But then the resupply vehicle would be nice to have. Man, it’s got to be a nightmare inside your head trying to think of everything.

Chel Stromgren: Yeah. Correct. And an interesting one is kind of on the flipside of the coin, another way that we can reduce mass that we also study as part of this is trash. So, you know, it’s kind of the heads and tails of the logistics world. We consume all these things that I’m talking about. At the same time, we’re producing a lot of trash. And trash is a great way to reduce the mass of the crewed vehicle during the mission because what we don’t want to do is, we don’t want to keep all that trash onboard. We want to find ways to get rid of that trash as the mission’s going on, so our vehicle is getting lighter and lighter. So, as the humans are generating trash, as we’re using parts and producing spares, as we’re producing waste gases and waste waters–I’m sure you’re aware of the regenerative ECLSS [Environmental Control and Life Support System]. We want to recycle as much as possible so we can produce clean water or clean oxygen from our own waste products. But then things we can’t recycle, we want to use either something like a trash airlock or a trash burning system to get rid of that stuff as quickly as we can and bring that spacecraft mass down. So that’s the other side of our job is looking at, you know, not only how do we supply it, but how do we get rid of it once we’ve used it.

Host: Yeah that is a big consideration there too. I guess that’s a benefit right there. You can kind of lose some of the mass, but it also is a consideration you have. I’m trying to think of other challenges along the way. One other thing that comes to mind is just the stuff you have. Right? Three years’ worth of stuff. Some of the hardware I think would be OK, but not everything can last three years. Right? I mean, I’m trying to think of just the food I have in my pantry.

Chel Stromgren: Yep.

Host: Only a few things I can think of really will last three years.

Chel Stromgren: That’s true. And that is a huge challenge that NASA’s working on. And you’re absolutely right. I mean, you know, it’s easy to react and say, “Oh I can go down to REI and buy, you know, camping food that has an expiration date of, you know, 2035 on it.” And while that’s true, you can’t live on that stuff for three years. Right? Because what happens is although, you know, it may be shelf stable for that long, the nutrients start to break down. And that food that is shelf stable for that long doesn’t provide a full spectrum of nutrition. So, it is a balance. And what’s interesting and very different from the space station is, you know, as part of these Mars mission that the [Mars Integration Group] MIG is planning right now, we’re assuming that up to 50% of the food is frozen.

Host: Wow.

Chel Stromgren: And we have never used frozen food or even really refrigerated food to any serious extent in space before. So that’s going to mean a whole new system on these spacecraft. I mean, we simply need to do that, well for two reasons. One is to keep enough nutrients in the food for that long and to keep this food, you know, edible and stable for that long, but frankly also just from a palatability perspective. You know, even on ISS the space food isn’t–they put up with it for six months. They’re astronauts. They’re tough. But what we find is, you know, a lot of times many astronauts don’t eat as much as they should. It’s just not really that appetizing to a lot of the astronauts. So, you know, the goal is, you know, by using a higher percentage of frozen foods, you know, which is essentially, you know, once it’s thawed out fresh food, you know, you can make it a little more appetizing, certainly more nutritious, and hopefully have a better profile for the astronauts over time.

Host: That’s big. And also, I mean one of the things I’m thinking of is now you have a bunch of freezers carrying half the food for your mission. That’s a lot of energy too.

Chel Stromgren: It’s a lot of energy. It’s a lot of mass. But, you know, one thing we’ve got at NASA is smart engineers. And they’re starting to figure out how to use things like, you know, heat pipes out to space. So, let’s use the cold of space to, you know, run the freezer instead of having to have, you know, a Freon system like you would in your house. So, I’m confident that, you know, those guys, the engineers who design that stuff can come up with a great freezer at a really low mass. And, you know, there may be ways to use those freezers on the way home. So, you know, as they get empty and we have, you know, frozen core samples from Mars, maybe we can put those frozen core samples into those very same freezers to get them back to Earth.

Host: Now, one more challenge I’m thinking of in terms of a Mars mission, and this is a little different because you’ve been referencing the International Space Station, which is a fantastic model. I think what changes, one of the main things at least for me that changes, is the environment. Now you’re introducing a lot more radiation and possible environmental challenges on that transit. How does that inform what you pack?

Chel Stromgren: It is a major factor in a couple of different ways. And one of the biggest ones goes back to a topic I referenced before, which is the reliability of systems. You know, like it or not, most of our spacecraft systems are turning into electronic systems, you know, software controlled, certainly process controllers. And one of the big concerns we have is that, you know, as I move out of the Van Allen Belt and I’m in this much more severe radiation environment, is that we’re going to see a lot more failures in that type of equipment. You know, we kind of know that from past experience, although we don’t have a ton of empirical data on how that happens. And frankly that’s one reason, you know, we want to leverage the lunar gateway so that we can start to get experience putting some of those systems outside of the Van Allen Belt, begin to understand what the failure rates might look like, so we can better plan for those failures and frankly design better systems, more radiation hardened systems, so we can protect against those type of failures when we go to Mars. You know, another way radiation can impact what we pack is we need to provide radiation protection for the astronauts, you know, both from background cosmic radiation, but if there’s a solar event during the mission we already know we’re going to have to have some kind of solar storm shelter that the astronauts can go down if there is a solar particle event during the mission. And one way to provide that, you know, is to use the logistics we already have. If we have a bunch of water, if we have a bunch of bags packed with food and spare parts, we can arrange those logistics in a way that, you know, they can form a fairly substantial radiation shelter for the crew. So, you know, when we’re talking about packing the spacecraft, it’s not only fitting it in, the radiation guys are doing their, you know, 3D radiation modeling to try to help us position all those logistics, you know, particularly around things like the crew quarters, so we can get that safe haven.

Host: That’s going to be very, very important. This will blend into our next topic real nicely. We talked about a lot of the challenges that are facing us on this journey to Mars. Now and you’ve already alluded to a lot of them, but let’s go through this packing list here. We’ve already talked about food and, you know, half of it being frozen. We’ve talked about the radiation shelter. That’s something you absolutely have to have onboard. Let’s talk about, you alluded to this one, the regenerative life support. Now what’s that going to look like?

Chel Stromgren: Sure. It’s one of my favorite topics. So, you know, of all the advances we’ve made on ISS in terms of, you know, designing spacecraft, I think one of the biggest ones is what we call regenerative ECLSS and it’s kind of a fancy name for saying recycling. So, you know, one of the biggest needs that humans have to keep alive in terms of mass is oxygen and water, right? We consume a huge amount of oxygen and water. And those are also very difficult things, they’re heavy things to deliver into space. So, we certainly don’t want to go to Mars carrying in tanks all the water and oxygen we would need to get the whole way. It would be tens of thousands of kilograms of extra mass we would have to push. So, what a regenerative ECLSS does is it takes the human waste products and essentially, either through filters or through chemical processes, recycles them so we can use them again. We sweat, we perspire. These systems will take that humidity out of the air. It’ll take our urine and it’ll put it through a series of advanced filters and chemical processes and produce clean potable water. Similarly, as we exhale and we produce carbon dioxide, we can collect that carbon dioxide, put it through a chemical process called a Sabatier, and it also produces clean water. And then finally, we can take that clean water, put it through an electrolysis system, and that gives us fresh oxygen. So, it’s this complete cycle of taking these waste products and running them through these various processes and at the end we get clean water and oxygen out of it. And we can basically do that to such an extent that we don’t have to carry really any additional oxygen and water. We get a little water through the food we consume and through metabolic processes and by doing this recycling we can make up the difference. So actually, when we leave for Mars, and I mean we’ll have a safety store of oxygen and water, but we basically bring no additional oxygen and water. We recycle that the whole way there and back.

Host: That is huge. I mean, that’s a lot of mass you’re saving right there.

Chel Stromgren: Yeah. It really makes the mission possible in my opinion.

Host: Yeah.

Chel Stromgren: It simply wouldn’t be viable to push that much. And then, you know, joined into that we’re also looking at things we can do on the surface to supply new water. You may have heard the term ISRU, In-Situ Resource Utilization. So, when we get there, we’re pretty sure there is water on Mars, so you know for the surface we’re starting to do experiments now. In fact, the next Mars lander is going to have a test experiment of this. We want to be able to take, you know, gases out of the atmosphere, we want to be able to take water out of the ground, clean that, and use that on the surface. Because again, you know the gear ratio is even higher to get to the surface. We don’t want to land any water or oxygen or as little as possible on the surface. So, if we can get to Mars and, to violate the initial analogy, actually stop and pick up some supplies at Mars, that certainly helps a lot as well.

Host: Alright. Yeah. That is really limiting the amount of I guess water and all of those consumables that you need for that mission. That is huge.

Chel Stromgren: Yeah. And, you know, really if you talk to anybody about space exploration, it’s really the key to opening up the solar system. Right?

Host: Yeah.

Chel Stromgren: Humans have got to learn to live away from Earth. We’re not going to be able to continue to bring everything with us we ever need. That’s simply not sustainable. So, the more we can recycle, the more we can make use of those type of products that we find along our way, the easier we’re going to be able to get further and further out into the solar system.

Host: Now on this topic of recycling, this is one that I’m extremely curious about because I know how they do it on the International Space Station, their clothes. I know they only wear them for a very specific period of time, and it changes with their daily clothes versus their workout clothes. But they trash it. They only wear it for a little bit and then they trash it. So, what are we thinking about for Mars?

Chel Stromgren: We’re exploring various different ideas. You know, frankly that may be the way that we go forward. Although we’re getting better at it. What you’re referring to on the ISS is they’re starting to use this new advanced type of clothing that has silver impregnated to it. Silver is a natural biocide, so it’s going to kill those things that come out in your sweat that start to cause things like smell. So, you can wear a pair of silver impregnated t-shirts for weeks and it really doesn’t get stinky. So that helps a lot. So, you know, we’re not talking about, you know, having to bring a new shirt every day. It’s maybe a new shirt for every couple of weeks. But to go further, you’re absolutely right. We’d like to avoid that all together. And NASA does have some programs that are starting to look at a space laundry. You know, we’d certainly like to be able to do that, to bring a couple set of clothes that can last three years and just to clean them as we go along. But there are some pretty huge challenges there. One is, you know, any type of water based laundry gets really difficult because again, you know, now although as we discussed with this regenerative ECLSS we could probably recycle that water but it makes the amount of water you need for a laundry is really large. So, it would make those systems much, much bigger. And, you know, there’s problems with the surfactants, you know, the type of things that are in laundry detergent that make them work, make the water much harder to recycle. But there’s some really good ideas that are being looked at. I know NASA’s looking at microwave-based laundry cleaners, things that expose the clothes to the vacuum of space to try to clean them. So, we’ll continue to look at those things and we’ll really try to hammer that clothing mass as well. Because you’re right, it does seem crazy to, you know, bring three years’ worth of clothing and then just toss them out as we’re going along.

Host: Right. Yeah. And if you have that ability to wash it or I guess disinfect it, that’s an interesting idea to microwave or expose it to vacuum. Yeah, just the idea to clean it, that really limits the amount of clothes, number of clothes you really have to bring so that’s awesome.

Chel Stromgren: Yep. Yeah. Yeah. So that’s one of the many technologies we’re going to push to try to reduce that logistics mass.

Host: Now, OK other things you need to pack aboard, obviously, you know, one of the main things you need for any trip is hygiene and care items, your toothbrush, your toothpaste. Now you’re talking about maybe toothpaste that’s got to last for three years. Any unique considerations there?

Chel Stromgren: Yeah. Hygiene supplies and even clothing to some extent get interesting because people have such personal preferences, right? You know, for a lot of the stuff we send into space, you know, NASA has their standard NASA issue items. But particularly when it comes to hygiene supplies, you know, people like very specific things. So actually, NASA has a fairly advanced process to qualify items. And even on ISS there’s a whole catalog of items that astronauts are allowed to choose from, and they do get to choose. They have a mass allocation and the astronauts, before they go up to ISS, get to go through and, you know, say, “I’d like that shampoo and that deodorant, and I like this toothbrush and this flavor toothpaste.” And to the extent that they can be accommodated, they can even ask for additional things to be put on that list. So if there is a very specific type of moisturizer that the astronaut really wants to have, as long as it’s not too challenging, it can be qualified, you know, making sure it’s not flammable, that it’s not going to be a problem in the ISS atmosphere, and then that can be added to that catalog. So, it’s a little thing. You know, it ends up being very complex because we have to go through this qualification process, but, you know, I personally think it’s absolutely critical to the astronaut’s kind of wellbeing. Right? The little things like that, you know, being able to have something that they’re used to using at home, takes away or helps to take away a little bit of the stress from these long spaceflights. So, we want to absolutely accommodate that type of thing as much as possible. So, you might have different astronauts with an entirely different hygiene kit, you know, kind of depending on what their preferences are.

Host: Alright. Yeah, that’s very similar. And I know those hygiene items, just from talking to some hygiene folks on this podcast actually, I got to understand that some of those hygiene items that are on that list are approved for that ECLSS system so it’s not going to affect it in any way.

Chel Stromgren: That’s right. And that’s part of that testing I was talking about.

Host: Yeah.

Chel Stromgren: You know, any spacecraft like this, particularly when we’re talking about regenerative ECLSS is an incredibly complex, you know, closed biosphere. So, you know, it’s tough to imagine the downstream effects, you know, just if somebody has a new spray on deodorant that has some kind of chemical in it, you don’t ever know how that’s going to get brought into the ECLSS system. It could start to foul filters. It could start to cause problems later on. So, there is an awful lot of analysis that has to take place to make sure that, you know, anything we bring is really benign. And as you said, on ISS it would be bad enough if it could cause problems, but you know on Mars if you weren’t really careful about that, and those systems failed, you know, that could be deadly. So, it is an incredibly intense process to make sure that everything is all compatible.

Host: Now, we’re talking about a lot of things you need to bring, your classic road trip sort of things, but we are going to be on this vehicle and that vehicle needs to have certain capabilities for the people inside. And I know one of the top considerations, and this is a big one even for International Space Station, is exercise equipment. What are we thinking?

Chel Stromgren: Yeah. Exercise equipment is a huge challenge for various reasons. One is, you know, exercise is not only, you know, just to stay in shape, it’s one of our primary kinds of medical counter measures. Right? So, you know, one of the big challenges we face in general is these long periods in zero gravity or micro gravity conditions. And we’re starting to understand a lot more from our research on ISS how that can cause problems for the health of the astronauts. And, you know, one of the best ways we have to counter that is for the astronauts to do exercise. So, it’s not only kind of yeah, we need to keep you in cardiovascular shape, for all those things like bone loss and things like that, the exercise helps with things like that. So, in fact, we anticipate doing even more exercise on these Mars missions than they do on ISS now. And they’re already doing a lot of exercise on ISS. So, we want to make sure we have systems that absolutely maximize that value. So, NASA’s actually doing kind of a test right now for the next generation of exercise system. On ISS, you know, right now we have various treadmills that they use, they have bicycle ergometers that they use, and then they have resistive devices, which, you know, kind of simulates weightlifting, that type of thing. NASA’s looking at systems that really start to maximize that and combine those functions more like in a universal machine. You can do more different types of varied exercises, you know, so they get around the boredom, exercise for muscles, so they’re more effective. So, we hope once these tests are done that, we’ll get an exercise system that not only is way more effective but weighs a lot less. One of the big problems we have with exercise systems is the isolation, you know, isolation from the systems. You know, you can imagine a treadmill creates a huge pounding force that can essentially, you know, in something like a space station could rattle the entire thing if it wasn’t very isolated. So, we not only have this big complex treadmill, we have to have this very complex isolation system, so those forces don’t get in. But now as we’re moving forward, we can design things, you know, more advanced systems, you know, better analysis. We hope to be able to get those systems much smaller, much lighter, but again, be much more effective.

Host: Yeah, that’ll be big, combining all of those things and making them smaller. Big challenge definitely ahead of you.

Chel Stromgren: Yep.

Host: The other one is, and this one I know just from not only the space station, but we have something here called [Human Exploration Research Analog] HERA where they simulate long duration missions and basically the human element of living together. This makes me think of living areas and sleeping areas. So, what are we thinking for a Mars transit vehicle?

Chel Stromgren: Yeah. And again, like so many of the things we’ve discussed, it’s this balance. Right? You know, there’s a desire from, you know, the propulsion guys to make things as small and compact as possible, but from a human health and human, you know, wellbeing side, we have to make sure that the astronauts, you know, are well taken care of. So, you know, we take things like sleeping spaces, personal quarters. You know, obviously the most efficient way would just to be have, you know, one space that’s, you know, they’d just sleep wherever they are. They all sleep together. We don’t have to have private rooms. But, you know, you can imagine on a three-year stressful journey that’s simply not going to cut it. So, we know that the astronauts are going to have to have their own sleeping space. And a space that they can go to for privacy, right? Sometimes they’re just going to need to get away from everything. Maybe they want to go watch a movie or they want to, you know, record a message for their family. So, you know, what we anticipate for this Mars spacecraft is it may be a little more sumptuous than we’re seeing on ISS. You know, each astronaut’s likely to have their own little cubicle. And look, it’s not going to be the Ritz, but, you know, it’ll be enough space where they can, you know, not only lie down, they might have a bench in there where they can sit, again read a book, with a closing door, with some acoustic insulation where they can really just get, you know, that time alone that they need. On the other side, we also need to encourage socialization. Right? We don’t want people, you know, just working all the time and then going off on their own. So, we’re also planning spaces where they can play games. You know, they will definitely have some kind of war table where they can sit and have meals, where they can play a card game if they want. We’re trying to make sure that they have enough open space that they could play a ball game or something. Right? We saw this on Skylab where they were very innovative. They ended up using a ring of lockers as a track that they could run around. We saw that they used that open space to play catch. We think things like that are very important. You know, that just downtime, relaxation. We really want there to be at least one big open space. We want there to be a place where they can sit down and watch a movie together. So, there’ll probably be a space where they can sit down with a large screen, you know, with enough places that they can all sit there as a crew and spend time together and watch a movie if they want. So again, very carefully balancing that need to keep things as small and tight as possible with keeping the crew healthy. And a lot of that is just going to be through smart reuse of spaces. Right? You know, we’ve got to have spaces that are reconfigurable. So, you know, the place where they exercise during the day, you know, we want those exercise systems to be able to fold away. So maybe that’s the same place they can all sit and watch a movie at night.

Host: Interesting. OK. Yeah, they have their own personal space to do these activities, but it can be interchanged. Very interesting.

Chel Stromgren: Yep.

Host: I know another one is I’m going back to food here for a second. But you did mention a lot of frozen food. I know there’s been experiments on the space station for growing plants and even recently they were able to eat some lettuce. So, is there any thoughts about adding possibly a farm for some fresh grown food on the way?

Chel Stromgren: We would love to get there. You know, the advantage to that would be huge again, just from a nutrition standpoint and a psychological standpoint. But there are some pretty significant challenges.

Host: Sure.

Chel Stromgren: You know, growing, you know, although with new aquacultures and things we’re getting better about water usage, growing plants does require additional water in the cycle. Now again, we can, by using our regenerative systems, we can recover a lot of that water. So, it may not be a huge burden, but it does make those systems more complex. The other challenge is again, you know, similar to that caching we talked about before is just the risk. You know, if you are depending on those plants growing and something happens, you know you get a system failure, the plants die, you get some blight or disease in there, now you don’t have enough food. So, my guess is, you know, at least initially we’re probably not going to have, we’re not going to depend on those foods. I think we’ll still do it. We’ll grow lettuce. We’ll grow cucumbers onboard. But it’ll be more for variety than replacing, you know, the other food we need to bring.

Host: Got it. OK. Now, of course there’s, you know, we’re talking about things to do. Right? We’re talking about their exercise, their gaming time, and just movie time. They’re going to have a lot of time to kill here on that nine months. So, I’m sure some of it is going to be dedicated to science and experiments.

Chel Stromgren: Yeah. So that’s an interesting analysis. The MIG is doing a lot of crew time analysis to see what the crew might be doing during that journey. We will make free time for science. I don’t want to imply that we won’t. But to some extent, you know, I don’t think the crew’s going to be sitting around looking for things to do. You know, we discussed before on ISS we went to this repair concept where we just swap out big boxes, specifically so that we can create crew time to do science. And that on the Mars vehicle, because of mass reasons, the crew will be doing a lot more detailed repair. So, you know, one thing we anticipate is that the crew’s going to be spending a significant portion of time just maintaining the spacecraft because things will fail. I mean, we know that. Things fail all the time on ISS and the crew repairs them. So, the crew will spend, you know, some time, “Hey, you know, we’ve got to replace this pump. We know it’s about to fail.” And there will be a lot of routine maintenance. You know, there’s a lot of filters, smoke detectors, things like that are going to have to be replaced. So, there will be a chunk of time doing that. But we will make sure there’s time to do science. So, we will put capabilities in place to do some experiments as we go along. And it’ll be a unique opportunity, right? Because although we may do some longer missions before then, it’ll probably be the first time that humans spend three years in space. So, a lot of those will be human experiments really upon themselves, measuring their own condition, their own, you know, neuromotor function, and things like that just so we can monitor how they’re doing as they go along. But there’ll be other things. You know, this will be, even when we’re in orbit around Mars before we go to the surface, it’ll be the closest humans have been. So, we’ll take that opportunity to survey the surface, to do things like that. So, there’ll be a lot of, you know, we want to maximize the value of the time, both when we’re at Mars and on the way there. So, we’ll make sure that they’re doing the right things.

Host: Absolutely.

Chel Stromgren: Yeah.

Host: Absolutely. Now, we’re at Mars. This brings up another thought just on the idea of packing. And we’ve talked a lot about just on the way to Mars things you have to have onboard with you. You did mention at one point when we were talking about the In-Situ Resource Utilization, the ability to have consumables onboard. And that makes me think of picking up stuff on that stop you’re making at Mars, whether it’s on the surface or otherwise for that surface mission, pre staging more stuff to stock up on for the way back home, maybe extra clothes, maybe extra spare parts that you’re putting on the surface of Mars. Is that a consideration or is that a little bit farfetched?

Chel Stromgren: Probably not on the surface because, you know, you wouldn’t want to put things on the surface that you wanted to use in space just because, you know, the hardest thing we do in spaceflight is getting off the surface, whether it’s Earth or Mars or wherever, right? That’s the highest energy. So, you know, we wouldn’t want to put stuff on the surface because the amount of propellant we would have to put on the surface also to get that back up to orbit again would be crazy. But again, we discussed a little bit before, caching, you know, in Mars’ orbit, you know, that’s something we definitely need to investigate. And you’re right, you know, maybe you can do it in a way that’s smart and reduces the risk. You’re right. I may want to have enough contingency food that I could limp back home if I didn’t make that rendezvous. But, you know, I might be willing to risk having stinky clothes. I might be willing to risk that, you know, I don’t have my full 50% of frozen food on the way home. So, in that case, you know, I could kind of split the difference and say, “OK well I’m going to put some of this stuff pre-positioned in Mars’ orbit in a logistics module. I think I can still get home if I miss that rendezvous, but under normal operations I would make that rendezvous, restock everything, you know, get new food in, new clothes, pack all my trash in a logistics module and continue the mission.” And that may be a good way to kind of, yeah like so many things, a nice compromise to, yeah, I’m not pushing all this mass, but I’m not endangering the crew if I’m not able to make that rendezvous.

Host: This is absolutely fascinating. Now I’m thinking about the short term here because we talked this whole time about a Mars mission, and you talked about this right in the very beginning and it excited me because we actually just did an episode on the Gateway.

Chel Stromgren: Yep.

Host: But I feel like there’s so much from Gateway that we can learn, whether it’s systems, whether it’s operations, what have you, while this thing is around the Moon that can inform what you pack on this Mars transit vehicle. So, what else? What is the full scope of things that you’re excited about for Gateway?

Chel Stromgren: Yeah. So, I’m actually a big fan of Gateway and I think it provides a lot of things for NASA as we move forward. One is, you know, and people I think don’t realize this, just the value of it being a pit stop. A place, you know, because I am a logistic centric guy, a place where you can collect logistics. So, when we’re doing these missions in the future, and it won’t just be a mission to Mars. You know, we might precede that with a Venus fly-by. We might precede that with just, you know, a long mission around Earth and solar space to test things out. We don’t have to be able to deliver everything directly to the spacecraft we’re going to use for those missions, because often that can be time sensitive. Right? We can use Gateway as a warehouse, in fact, to build up logistics over a number of years before we have to depart. So, you know, you’re probably aware that there’s this new Gateway logistics service where we’re going to hire private companies to deliver logistics to Gateway. Essentially what we can do is we can take advantage of that every year, collect the logistics we need for these longer missions like the Mars missions at Gateway, stage them there, and then launch that spacecraft empty. Again, much easier to launch when it’s empty, and then load all those logistics from Gateway when we’re ready to go. So that in itself operationally is just a huge thing. That’s the same reason we want to run the HLS missions to the Moon out of Gateway. We don’t want to have to launch everything we need to go to the Moon with that lunar lander, because that’s very heavy. Right? So, things like the food they’re going to consume on the surface, the EVA suits they’re going to use on the surface. It’s much better for us to launch that via this unmanned vehicle to Gateway, meet the lunar lander there, and then load that stuff in there so we can go down to the surface. Again, so operationally I think Gateway makes stuff a lot easier. But it’s also, you know, I said before how ISS is the best possible experiment. Well, Gateway is gen two of that best possible experiment. So, you know, although ISS is mature and sometimes hard to put new capabilities, we can put those new capabilities into Gateway and test them there. And again, now we’re beyond the Van Allen Belt, so it’s a more analogous environment to what we’re going to see going to Mars or Venus or somewhere. So, when we start looking at things like the radiation impacts, the deep space impacts, even things like communication delay, because we can certainly talk about that because that’s another huge operational issue, the Gateway is a better analog than even ISS. So, we can get closer and closer to the actual mission, test things in that relevant environment, and make sure they really work.

Host: Yeah. Let’s investigate that for a little bit, that communication delay. Does that impact what you have to pack onboard or I guess the operations along the way as well?

Chel Stromgren: To some extent it impacts both. So, you know, we know that the astronauts are going to have to be more autonomous. You know, if anybody’s kind of seen ISS operations, the astronauts get a ton of support from ground control. You know, they always have the experts standing by in ground control and certain things like when they’re doing repairs, they have somebody constantly talking in their ear. Right? So, the astronaut, you know, may not have to have read the entire manual. They’ve got the guy with the manual on the ground who can say, “If you look three inches to your right, you’ll see the right wire. Now, turn it a quarter turn counterclockwise.” The further away you get from Earth, the harder that operating mode gets. Right? Until you get to Mars where, you know, the roundtrip can be, you know, almost an hour. So, you can’t sit there and say, “Oh, do I cut the red wire or the blue wire?” And then wait for an hour to learn the answer. So, to some extent, the astronauts are going to have to be more self-sufficient in doing everything, you know, running the spacecraft, controlling their own lives, certainly in things like doing repair and doing science. And that puts a lot more burden on the astronaut, but it also requires new systems. And a lot of those are going to be training systems. NASA’s going to have to develop systems that train the astronauts to do specific tasks during the mission. Because they have human limits, right? I think James Michener wrote that, you know, the Apollo astronauts learned as much as the human memory could possibly take about that spacecraft. They simply couldn’t have learned anymore about the Apollo spacecraft because it was so complex. The Mars spacecraft is going to be ten times more complex than that, so they simply won’t be able to know everything. But, you know, if they’re about to do a specific repair, they have to repair the water processor, what we want to be able to do is have remote training, which includes maybe 3D interactive training onboard, so prior to doing that repair then they can become experts on that specific repair they need to make. So, you know, maybe they can virtually repair it ahead of time. They can get the knowledge from the experts on the ground so that when they go to repair that water processor and they have that one-hour communication delay they can still proceed reasonably well, and they can be expert enough to effectively execute that repair. And that’s going to be a huge challenge, you know, just being able to do things without constantly checking back with ground control.

Host: Now, let’s Chel, let’s play king for a day. I’m going to go back to Gateway here for a second. And the reason I want to focus on that is because that’s coming up here in the near term. We’re talking the next few years having the Gateway as this test bed to figure out what we’re going to need for a Mars mission. So if you were king for a day, what were some of those things that you would have the astronauts do that you would put on Gateway that you want to verify to make sure that everything you’re thinking for packing for a Mars mission is going to work when we actually make that Mars transit vehicle?

Chel Stromgren: Yeah, so there’s various things that we’re talking about doing on Gateway. You know, one of them, and it’ll be a combined ISS and Gateway, but again, the next generation of ECLSS system. We talked about ECLSS a lot in the past. The ECLSS community is constantly trying to improve those systems based on lessons learned on ISS, trying to make them more efficient, so we can close that loop even more, you know, recover more water and oxygen. But, because we depend on those things so much, we have to make sure they’re reliable in space. So, to me it’s absolutely critical that we get those things on ISS first and then on to Gateway, again because of the different environment, because of the isolation, because of the radiation. We need to test those in both analog environments and get as much run time as possible. Because it’s not just getting up there and making sure they work. It’s getting them running for a long enough time that we start to understand the reliability and the failure rates. And that’s true for all these systems. You know, we’re going to have advanced communication systems. We’re going to have advanced avionics. We’re going to have advanced thermal control systems. You know, from the packing side of me and understanding the reliability and understanding all these repair activities, I want to get as much time in space with and without crew as possible so I can understand those systems as best I can before I leave for Mars. So, to me that’s the number one. The number two, you know, is what we just discussed is to start to develop these new types of procedures that allow the astronauts to work more autonomously. I mean, again, you know, we’re not talking hour delay when we’re at the Moon. We’re talking, you know, maybe 12 seconds roundtrip. But that’s enough that it breaks that instant chain, right? It’s not, you know, like we’re talking now where I talk, you answer, I talk, you answer. It’s a I’ve got to compose my thoughts, transmit it, they compose a response, and transmit it. And so even getting as far away as Gateway starts to give us that real world experience of OK, now I have to fix this thing. I’m not going to have instantaneous feedback. So, we can start to test things like autonomous training and start to really understand from a human perspective, you know, how do you teach a guy in this stressful environment who’s not an expert on this system to make these types of repairs. So, personally I want to make sure, you know, if we are going to go down at this lower level of repair, that we start to test those kind of things at Gateway so we can, you know, really understand how to train the astronauts to do them in space.

Host: You know what’s exciting to me, Chel, is just how soon this is going to happen that this is something that’s in the very near horizon we’re going to be able to test some of these things. And it gets me excited about the Mars mission, which is again, sure in the future, but man this is a new generation we’re talking about. What are your feelings about the Artemis mission and going forward, laying that foundation and testing all of these critical things like regenerative life support, making sure that, that’s ready for a Mars mission? What excites you the most?

Chel Stromgren: I think what excites me the most is you can kind of tell the atmosphere around NASA has changed a little bit. You said something interesting. You said this Mars mission’s off in the future. And the whole time I’ve been working for NASA, you know, the Mars mission was always 20 years away. Didn’t matter when you were, it was 20 years away. You know, we were always kind of focused, well we’re focused on ISS and we’re focused on SLS and Orion. The difference in the last few years is, you know, although we are focused on HLS and Gateway, there’s a much more of a feeling of this is really leading to an actual Mars mission. And I think a large part of that is the establishment of the MIG. You know, the MIG is not designing, you know, a Mars mission, you know, theoretically that could happen sometime in the future. They are designing, you know, the Mars mission we think we can actually execute in the 2030s. And then they are working backwards from there to define exactly what capabilities need to be developed. And then we are absolutely trying to make sure that the development of those capabilities get incorporated in what we’re doing in ISS, Gateway, and HLS. So, there may be aspects of HLS that are done not because they’re optimal for HLS, but simply because they support this future Mars mission. Because we don’t want to get stuck in this 20 year away paradigm. We want to start working through those challenges. So, we’re 19, 18, 17 years away and we actually can get there.

Host: That is big. Chel, thank you so much for coming on Houston We Have a Podcast today. This was so fascinating to just hear all of the stuff you need to consider for a Mars mission. And then what’s really exciting to me is we’re going to be testing a lot of those things in the very near future and getting a good foundation. And you’re going to see the hardware that’s going to come up and is going to really make that Mars mission, as you’re saying, more of a realistic thing. Man, that you can actually put your eyes on it. Wow, this is something that we can actually use for Mars. Very, very exciting stuff. Chel Stromgren, thank you for coming on today.

Chel Stromgren: Oh, thank you. It was great. Hey, it’s great that people can understand a little bit more about some of these challenges.

[ Music]

Host: Hey, thanks for sticking around. Really fascinating conversation we had with Chel Stromgren today about what to pack for Mars. I really hope you’re enjoying our Mars Monthly episodes that we’ve been doing here on Houston We Have a Podcast. This is the fifth in our series. You can go back and listen to them in order or not, up to you. The last one we did was 156 with Paul Kessler about the Deep Space Transport. Another one I would suggest is 157 where we talked to Dan Hartman and Lara Kearney about the Gateway. We made a lot of comparisons to Gateway during today’s episode, so if you want to know more about that vehicle, go ahead and check out that episode or any of our I guess, 160 episodes that we’ve done of Houston We Have a Podcast. You can check us out at NASA.gov/podcasts. Click on us, Houston We Have a Podcast, or the many other podcasts we have across NASA. If you want to talk to us at Houston We Have a Podcast, we are on the NASA Johnson Space Center pages of Facebook, Twitter, and Instagram. Use the hashtag #AskNASA on any one of those platforms to submit an idea for the show. And make sure to mention it’s for Houston We Have a Podcast. This episode was recorded July 10th, 2020. Thanks to Alex Perryman, Pat Ryan, Norah Moran, Belinda Pulido, Jennifer Hernandez, and Michelle Rucker. Thanks again, to Chel Stromgren for taking the time to come on the show. Give us a rating and some feedback on whatever platform you’re listening to us on and tell us how we did. We’ll be back next week.