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 142, Michelle Rucker, Mars Integration Lead at NASA’s Johnson Space Center, discusses how we are building on our current knowledge and capabilities and breaks down the considerations for getting to, living on, and getting back from Mars on this first 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 January 8, 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 142, “Preparing for Mars,” I’m Gary Jordan; 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. We have nearly 20 years of continuous human presence on the International Space Station. That’s nearly 20 years of studying the human body, understanding systems, and fine-tuning operations, for how to conduct human spaceflight missions, not to mention the decades of human spaceflight missions and experience before that. A lot has changed over time, based on what we’ve learned, and a lot of questions have come up that are important to understanding how things will change when traveling to Mars. You might think, that’s a lot of experience already, so why don’t we just go to Mars. It’s hard to imagine just how hard Mars is. It requires near absolute perfection, and any deviation may be a risk to the safety of the humans onboard or the success of the mission. So, the question is, are we ready? You can even ask, how ready are we? Luckily, we have an organization right here at the NASA Johnson Space Center, and all across the agency, looking at what we have and what we need to make a Mars mission successful. Michelle Rucker is a Mars Integration Lead at Johnson Space Center for the Mars Integration Group, a team that spans across all of NASA. She’s a 33-year veteran of NASA, joining in the aftermath of the Space Shuttle Challenger accident, and supporting the investigation by conducting booster material tests and analysis. She has participated in a range of exciting projects, such as the International Space Station Environmental Control and Life Support Systems, hypervelocity impact research, spacesuit and space walking tools, space station exercise equipment, system engineering, and Orion Crew exploration vehicle testing and verification. She currently leads the Mars Integration Group, developing crewed Mars mission concepts. She holds two U.S. patents and has authored numerous technical publications. So, on today’s podcast, Michelle goes over the details of what we know, what we have, what we need, and how NASA’s Artemis Program, that will establish sustainable human presence on the Moon, will help inform and fine-tune the ideal mission structure for a Mars mission. And I hope you like this topic, because there’s going to be a lot more. This month kicks off monthly episodes that are all about a Mars mission, and we’ll call it “Mars Monthly.” Over the next few months or maybe even the next year, we’ll dive deep into the various elements we discuss today with Michelle. So, here we go, preparing for a human mission to Mars with Michelle Rucker. Enjoy.

[Music]

Host: Michelle Rucker, thanks so much for coming on the podcast today.

Michelle Rucker: Thanks for having me.

Host: So, this is an interesting topic. I’m really excited to talk about how we’re preparing for Mars. There’s a lot to consider, and it seems like it’s a pretty small group doing it. I want to get a little bit of sense of your background though, to understand what has to go into the people that are actively thinking about what we need for Mars. What’s your background?

Michelle Rucker: So, I was born in Alaska. So, extreme environments don’t scare me. So, that’s probably the first requirement for thinking about Mars. I went to school here in Houston, at Rice University. I’ve got a couple engineering degrees in mechanical engineering. I started my career at the White Sands Test Facility in New Mexico.

Host: Oh, right at NASA. OK.

Michelle Rucker: With NASA, yeah. If you’re not familiar with White Sands, we do all the fun hazardous testing stuff out there. So, that means blowing stuff up and setting it on fire and shooting micrometeorites at it. So, I spent the first part of my career trying to destroy spacecraft. But at some point, you get tired of that, and you want to start creating. So, I transferred here to Johnson. I worked on the space station with the life support systems. I did stints with the exercise equipment. That was one of the funnest jobs I did. I also worked with the Constellation Program, for both the Altair Project and the Orion Project. And then when the Constellation Program wound down, I started doing exploration for the first time. So, I’m relatively new, compared to some of the folks who have been working about — working on Mars for years now. I’ve only been doing Mars work for maybe the last eight or nine years.

Host: That’s still significant, but I think what’s important is, you have a — you have that breadth of experience. You did a little bit of this, a little bit of that. The space station is really important. We’re going to fold that into today’s story a little bit. So, I think that’s a really good background to have. Now, you say you’re new, but eight or nine experiences — eight or nine years. That’s a lot of experience, to me. So, just from what you’ve learned, in your eight or nine years, thinking even just all the way back actually, to when we first started here at NASA, thinking about Mars Missions and what we need from Mars missions. What were we thinking about?

Michelle Rucker: So, Mars missions — the history within NASA is sort of interesting. Only a few weeks after the Apollo 11 landing, Wernher von Braun put together a proposal for a Mars mission, essentially taking the lunar hardware that he just developed successfully for the Moon, and supersizing it and going to Mars. So, that was an initial proposal. At the time, the agency was focused on the Moon. When the Apollo Program wound down, NASA focused a little bit more on low-Earth orbit. So, the shuttle and the station era, we were a little bit closer to home. But even during that period, there was a small office — both here at Johnson Space Center and across the agency, there were small groups working on some of the Mars technologies, thinking about some of the mission concepts. To me, Mars is a system engineering problem, as much as anything. We know how to do most of the individual pieces. It’s how do you put it all together, into a single mission concept, to be successful.

Host: I see. And that’s where some of the work you’re doing is coming in. It’s taking all those separate pieces and thinking about them and actively putting them into what we’re thinking about now, with what resources and technologies we have now, but thinking just further ahead and way further out.

Michelle Rucker: Yes. So, taking the technologies we have, looking at whether we need to supplement those with new technologies. Do we need to extend the technologies a little bit more? Think about operations. Operations have changed a lot over the years, Now, we’ve got the commercial players involved, and that’s an exciting new development. So, things have become a little bit more streamlined. Some of the things, the way we did business, even for procurements, back in the shuttle and station days, we’re developing new and faster techniques for doing procurements, so that’s exciting, as well.

Host: OK. So, let’s go right into it, thinking about those challenges for Mars, the things that are going through your brain all the time. What are we thinking about, when it comes to what to do, what to integrate, into a Mars mission?

Michelle Rucker: So, what’s interesting about human spaceflight is the entirety of human spaceflight has literally revolved around the Earth. Everything that we did with the Moon, the Moon revolves around the Earth. Everything we did with the space station, with shuttle, we all — it was all revolving around the Earth. In order to get to Mars, we have to change our coordinate frame of reference. We have to start thinking about revolving around the sun. So, first we have to chase Mars around the sun, to catch it. And then once we get there, Earth wasn’t where we left it, so we’ve got to chase Earth back around the sun, to get home again. So, it’s a bigger scope problem than the types of missions that we’ve been focused on. So, the challenges, I like to break into really sort of three pieces. There’s the getting there, the living there, and the coming home. So, are you ready to step through the pieces?

Host: Let’s do it. [Laughter]

Michelle Rucker: So, the getting there. So, the trajectory guys like to say that it’s 2,000 times farther — it’s like the odometer reading — to get to Mars and back versus trying to get to the Moon and back. And again, that’s because both Earth and Mars are moving, so it’s not just a straight line there and a straight line back. You’ve got to chase these planets around the sun. So, 2,000 times farther than the Moon. It only took us a few days to get to the Moon. You can go to the Moon and back in a week. To get to Mars and back, that is — that’s a little bit different. How long it takes — the transit time — is a function of when you go, where the planets are, relative to each other, at the time that you leave, and what kind of ride you’re riding in. But typically, we’re talking two to three-year mission durations. So, that’s a much longer mission duration than the types — even the longest expeditions we’ve done on space station to date. It’s only been a year. So, these are very long missions that we’re looking at. So, a long duration mission means you need a lot of stuff. You need a lot of food. You need a lot of oxygen. You need a lot of spare parts, a lot of consumable parts. And that means we need to launch a lot of stuff from Earth, or we need to figure out a way to either make it or find it somewhere, either at our destination or on the way. Once we get to Mars’ orbit, we will need to land a fairly large payload. To date, the largest thing we’ve landed on Mars is the Curiosity Rover. It’s about one metric ton. The smallest human rated vehicles we’ve been able to squeeze — we’re looking at crews of maybe four people. A crew of four is still probably going to require about a 20-ton, 20 metric ton lander, so that’s 20 times as big as anything we’ve landed previously. And unlike Earth, Mars doesn’t have a nice, thick atmosphere, where we can use it to help slow down. So, our entry descent and landing is challenging. The other problem with Mars is global dust storms. You may have read about the Opportunity Rover unfortunately –yeah, met with a tragic end, with the dust storm in 2018, I believe. So, dust storms can obscure the landing site. So, that’s another thing. We need technologies that would be able to deal with that, or we need to plan — have good weather prediction and be able to plan around dust storms. So, once you get there and land, then there’s the living there. So, in some ways, Mars is a lot like home. There’s a day and night cycle on Mars. A day’s a little bit longer on Mars. It’s about 24 hours and 37 minutes. It’s got mountains. It’s got valleys. I’ve seen photos that the rovers have taken, and it looks just like the desert Southwest in some places. So, lots of beautiful vistas.

Host: Wow.

Michelle Rucker: It has seasons. So, a Martian year is about twice as long as an Earth year, but it does have seasons. On a balmy summer day, it can be as warm as 80 degrees. So, in some ways, Mars is attractive, because it seems hospitable. It’s also exotic. It’s got two moons, Phobos and Deimos. If you’re into Greek mythology, they were the twin sons of Ares, I believe. They’re itty-bitty moons, but I’ve always thought it was kind of cool, that if you were sitting on a Martian surface, looking up at the night sky, the moons cross each other in orbit, which is kind of cool.

Host: Wow. That would be a sight.

Michelle Rucker: That would be pretty neat, yeah. But Mars is also challenging. So, it’s got reduced gravity. Humans are used to 1G, and Mars is reduced — if you weighed 100 pounds on Earth, you’d only weigh about 38 pounds on Mars. But because there is gravity, the challenge is that carrying around a big, heavy spacesuit becomes more problematic. We never worried about that too much in the ISS days, because with microgravity, a big, bulky spacesuit wasn’t really a problem. But on ISS, you don’t really walk. You use your hands to translate around. So, our spacesuits will need to be redesigned for a planetary surface. Once you get on the surface, humans are going to need a lot of power. Got to upload those selfies, right? You’ve got life support, communication, mobility, whatever science we’re going to do on the surface, so we’ll probably need a lot of power. The conventional wisdom is while we’re in space, we just use solar, but Mars is a little bit further from the sun than Earth is, so there’s reduced solar energy there. The other problem is the dust storms. The dust storms — that’s what happened with Opportunity — the dust storm knocked out the solar energy, and poor Opportunity didn’t make it. So, we need to look at some alternative sources for power. And it can get cold, in some places, in some seasons. So, it’s a pretty extreme environment. So, now if we’ve finished up our mission on Mars, we’re ready to come home, all of the Mars missions to date, all of our robotic missions, have been one-way affairs. We’ve never actually tried to launch anything from Mars. So, Mars does have a lower gravity, so getting something off the surface of Mars would be easier than getting something off the surface of Earth. But we still estimate about seven kilograms of propellant for every one kilogram of mass we’re trying to get into orbit. Each crew member is going to be, you know, maybe 100 kilograms. So, you’re talking about a lot of propellant. We’ve estimated up to 38 metric tons for a four crew with science equipment and their EVA suits and so on. So, that begs the question of, do we bring all that propellant from Earth, and then try to land it, or do we figure out a way to make propellent there? Those are some interesting questions. Once you get back into space, getting your deep space transport come back to Earth, you’ve got the Earth reentry problem. It’s about 11 kilometer per second reentry back into Earth. That’s what Orion — that’s the challenge Orion was designed to overcome. So, those are the challenges. And all of those taken together could be daunting, if you were trying to start from scratch, to solve all those challenges. But the cool thing about what NASA’s been doing over — ever since Wernher von Braun first proposed Mars — is we’ve been whittling away at these challenges, piece-by-piece. So, we don’t have to start from scratch. A lot of the projects that you may have heard about recently, Artemis, the Human Landing System, the Gateway, plus ISS shuttle experience, some of the EVA suit development work that’s been going on, all of that will contribute to helping us solve some of these challenges.

Host: That’s significant. That’s a lot of consideration. I mean, that was — what you just described, right there, that little packet, was the whole — was the Mars mission. It was getting there. It was living there. It was coming back. It was in those three sections. And it’s — I’m smiling over here. You can’t see it, because we’re on the podcast. I’m smiling but, I mean, you make it sound like — and that’s it. And that’s what we need to do. But I know it’s so hard. There’s a lot of challenges that are associated with this, in terms of what we’re investigating. Let’s kind of dive a little bit deeper into some of these challenges, starting with getting there. I pulled out a couple key elements, and as you were going there, you know, you’re like, oh, that’s a challenge. But I know it’s like — it’s a really big challenge. So, one of them was just distance, just being far away is just — makes everything so much more complicated, because with being far away comes — you have communication delays. You’re talking about a significant amount of energy to get there, a significant amount of time to get there, and then the positions — like you did mention this — the positions of Mars and Earth have to be in such a way that meet the requirements, to actually go catch up with Mars. That’s all very significant things.

Michelle Rucker: It’s pretty astonishing that there are smart guys who can calculate precisely where Earth and Mars will be at any given instant in time, with such phenomenal accuracy. It still amazes me. We actually rely on — we’ve got a team here at Johnson, the [Mission Analysis and Integrated Assessments] MAIA team, that does a lot of trajectory analysis. We also use some folks at Langley Research Center that do trajectory analysis, and also, we’ve got some team members at the Glenn Research Center that help us with that. So, yeah, we spend a lot of time trying to figure out exactly who’s where, when. On ISS, if you run out of something, it’s pretty easy to resupply it. If you’re halfway to Mars, it’s a little bit harder. You can’t really get supply on demand, so you have to do a lot of logistics analysis, predict exactly what you’ll need when you’ll need it. One of the cool projects we’re working on right now with ISS, we’re talking to them about using ISS to help refine some of our logistics models. They do really good tracking of what goes up and down, but because they have on demand, they don’t have to necessarily predict very far in advance. We’ll have to predict out up to two or three years in advance. So, one of the things we’re doing is talking to them about — let’s start developing some models, to predict what you’ll need on ISS, and then we’ll look at actuals and see how close we came to that. So, we’re using ISS today as a way to help refine some of the tools that we’ll need for Mars later.

Host: Interesting. You’re almost — it’s kind of like over-planning, you know. Like you’re not just resupplying what you need on the space station because, as you mentioned, it’s — your time constraints aren’t as drastic as Mars. So, let’s just pretend that we’re — you know, we have to model what we need, what we will need, what we’re going to run out of for the next two years. So, ISS is the perfect place to practice that.

Michelle Rucker: We’re also using ISS as a — we’re in discussions with ISS to use returning crew members as a Mars analog. So, after six months in microgravity on ISS, physically they’ll be in about the same condition as a crew that’s about to land on Mars. So, we’ve been working with the Human Research Program to develop some experiments, where returning ISS crew members will do some simple tasks — nothing that would be dangerous for them — but just to try to understand what we — what the crew could be expected to do on Mars. We obviously try to automate as much as we can, but if the crew needed to go do an emergency EVA, to go repair something, for example, the question is, how soon after landing would they be able to do it? After having spent six months on ISS, there’s an enormous crew of people here on Earth that greets the returning crew and, you know, picks them up and carries them where they need to go and, you know, doesn’t let them do anything strenuous for the first few days. They won’t have that opportunity on Mars. They could potentially be asked to do things that they would never be asked to do here on Earth. So, we want to understand what the capabilities will be. Are there counter-measures we can use, to try to make sure that they’re in good enough physical condition — strong enough, with good enough balance — to be able to do, not necessarily strenuous things, but things that could be dangerous, if you are far away from a doctor. You lose your balance and fall, for example. And yeah, so we try to think ahead to those sorts of things and use the available programs that we have in place today, sort of piggyback on those, where we can.

Host: Interesting. So, it’s like you’re trying — you’re using crew members returning to the planet, as a way to think about, if astronauts were on a very long journey to Mars, and you said — what was it? It’s nine-ish months to get there?

Michelle Rucker: It depends on when you — which opportunity — exactly when you leave, where the planets are, with respect to each other, and which propulsion system that you’re using.

Host: That’s an important distinction. But just, I mean, regardless, it sounds like it’s going to be a relatively long time, about what we’re doing now on the space station, give or take. So, when you land, I guess, what the human is going to be able to do, what we could do to try to — counter-measures we can put in place, to see how we can maybe help them get ready to do something. Another thing that’s coming to my mind is technology to maybe support — maybe holding them in place for a little longer — life support systems and the necessary provisions, so that maybe, during this recovery phase, they just need to wait it out. Maybe they have that ability. Because I know — I mean, I’ve been out to Kazakhstan. I’ve carried an astronaut, and I know, they are just like — I mean, but they get put right to work, right? So, they have to do these tests that you’re saying right now, they have to do these tests to see — to test performance. So, they’re out there moving, but they are — they’re dizzy. They’re dizzy, and they’re — they’ve had a long journey, and their bodies are adjusting. So, modeling that is important.

Michelle Rucker: So, that’s one of the unknowns, is — so, here on Earth, they don’t have to get up and do anything right away. There’s a crew there to help them. One of the things we want to know is how soon could they safely get up and do certain tasks without risk. So, that’s sort of an exciting area of research, that we’re partnering with HRP on. Back on the transit question — how long does it take to get there?

Host: Sure.

Michell Rucker: So, one of the things that we’re looking at is, can we minimize either how much propellent it takes to get to Mars and back, or the transit time, or both. So, we’re looking at a range of new technologies. Electric propulsion is an interesting one. So, the Gateway will be using solar electric propulsion. Those electric thrusters are of interest. We sort of see that as the evolutionary path for the Mars system, so Gateway essentially becomes our test bed for that propulsion system. Gateway also — the other thing that Gateway does for us is outside Earth’s protection. So, it will give us some deep space experience, in a harsher environment than a little bit closer to Earth, with the radiation and so on. Long duration missions, that that was one of the challenge, because of the distance to Mars and back, you’re looking at long durations. ISS has already given us the long duration human exposure to spaceflight, so we have a much better understanding of that than back at the time when Wernher von Braun first proposed a Mars mission. ISS has also given us a lot of long duration equipment experience. We understand, you know, the mean time between failure and certain types of systems. We’re looking at regenerative systems, trying to be more self-sufficient. So, ISS has done a lot for the Mars concepts. The new commercial partnerships that — some of the launch capabilities that we have available now that von Braun didn’t have, if we do need to launch a lot of propellant to get to Mars, we have more options now than we used to have. So, that’s exciting. Being able to land large payloads on Mars, we’re developing and testing several different technologies. My personal favorite is the Hypersonic Inflatable Aerodynamic Decelerator. The acronym is the HIAD. That’s a pretty cool system, to be able to use the — it’s a big, giant inflatable that gives you enough surface area to help slow down your payload before you land on Mars. The other thing Gateway will do for us is — I always say that lunar landers coming and going from Gateway to the lunar surface will look very similar operationally to Mars landers coming and going to the deep space transport. So, Gateway will offer us an opportunity — Gateway paired with the Human Landing System will offer us a lot of relevant operational experience that will be directly applicable to what we want to do on Mars. On the living there challenges, we already have a lot of experience with microgravity, which we need for the transit leg of the mission, from our shuttle and ISS experience, but the Artemis program will give us some reduced gravity, lunar gravity, experience on the surface of the Moon that will have some applicability. For example, spacesuits. We’ll need to develop a planetary suit for the Moon, something that you can walk around in. The hip joints, the boots that we use on ISS are not really appropriate for walking around in a dusty environment. So, that’s something that we’ll get from the Artemis Program. And then surface power, we’re looking at a couple options. Just oversizing the solar rays, more surface area, is one way to go. Another way to go is a compact fission power system. Our space — our technology mission directorate is looking at some alternative power sources to solar that are of interest to us. The Moon is cold and dusty, just like Mars will be, so that gives us — especially during the lunar night. It gets pretty cold, so Artemis will give us a lot of experience with the extreme environments. And then on the coming home again, we’re looking at — we’re looking to the Human Landing System, the lunar ascent element may be directly applicable, getting from the lunar surface back up to Gateway is not unlike getting from the Mars surface back up to Mars’ orbit. So, we’re looking to that program for some — maybe some get ahead on a Mars ascent vehicle. And then of course, once we get back to Earth orbit, or cislunar space, Orion has already solved the problem of getting the humans back to the ground again, so that — we checked that off of our to-do list. We just rely on Orion. So, a lot of the challenges have been whittled away or have been at least whittled back enough that they’re within reach now, for us to use for Mars.

Host: Yeah. I pulled out a couple — because you went through those same three key areas, getting there and living there, and then coming back, I was thinking about things that were either — we either have or are working on right now — regenerative life support was one that I pulled out, because I know that’s an important part of living and working on the space station, which we’ve been doing for almost 20 years now. And developing those technologies, that’s just something that we have a lot of data, a lot of experience with, and is going to be needed for Mars missions, something that we have, but the one thing I was really looking forward to is all this Artemis stuff that you’re talking about. You’re talking about all these technologies that are helping us to get to the Moon, yes, but in a sense, there’s a lot of applications, and important applications, for a Mars mission. That was one thing I think was — it can’t be really understated, because we talked about how hard Mars is, but this Artemis as almost a practice for Mars, and preparation for Mars and data — data gathering for Mars. That’s really important.

Michelle Rucker: Right now, we’re thinking of the Moon as our test bed.

Host: Yeah.

Michelle Rucker: We will — obviously, the cheapest place to test these things is on Earth, and we will test as much as we can on Earth. I’m sure my friends at the White Sands Test Facility are excited about doing a lot of hazardous testing out there.

Host: Yes, alright.

Michelle Rucker: So, we will test as much as we can on Earth, but at some point, you’ve got to get some relevant space experience. There’s only so much you can do in microgravity. Microgravity helps us test the transit leg, but it doesn’t really do much for the planetary piece of it. The Moon gives us that. It gives us operational experience, a lot of materials reliability experience. We’re pretty excited about all the testing that we can do on the Moon.

Host: Yeah. Now, you’re — the group you’re in and the work that you’re doing is mainly — is it informing? Is it advising? Is it actively thinking and writing down requirements for what you think we’ll need for a Mars mission? Or what we think we should be working on now to prepare for a Mars mission?

Michelle Rucker: We’re not quite to the point of writing requirements.

Host: OK.

Michelle Rucker: Well, with one potential exception. So, we’ve got the Habitat Broad Area Announcement, [or Broad Agency Announcement] the BAA effort that’s going on. That was a procurement to look at an in-space habitat, which would potentially have applicability as the deep space transport habitat. So, that is one specific procurement where very high-level requirements have been defined. We’re not quite to the point of defining requirements for many of the other systems yet, but we are developing concepts, concepts of operations. Being able to jump into requirements should go pretty quick, when we’re ready to pull that trigger.

Host: OK. But you’re thinking about at least the elements that you’ll need. And we went through a lot of them. You just mentioned a habitat. I mean, one of the main parts of a journey to Mars is the actual journey to Mars, is getting there. So, there’s going to be some form of a vehicle transportation technology, whatever, to actually transit from Earth to Mars, from Mars to Earth. So, thinking about what we might need to — what that may look like, what we’ll need to consider. Because it’s a long time. It’s going to be a long time. So, thinking about those things ahead of time is really important. And then another part that I pulled out besides your three, thinking about the technologies we have now and are testing, thinking about the technologies that are coming up for Artemis, another part that I pulled out was — and this is a very important part — the human element, thinking about what a person is going to have to deal with. And you already talked about the landing, considering a landing from the International Space Station, from low-Earth orbit, having that be a model for what a Mars mission would look like. It sounds like there’s a lot of human components for Artemis, as well.

Michelle Rucker: Correct. Our team, we are so lucky. Don Pettit has been assigned as our crew rep.

Host: Wow.

Michelle Rucker: And he is — he’s so awesome. If you haven’t ever googled his ISS YouTube videos, he is —

Host: They’re fun.

Michelle Rucker: — he is fun to work with. So, Don’s been involved with us. Yes, we have been doing a lot of thinking about the human systems. Most of the — a lot of the Mars focus of the last few years was with the science, with the Rovers, the robotic missions, the science missions. The human missions are completely different. The science missions have taught us a lot about Mars, about the conditions on Mars, what we can expect on Mars, and that is extremely valuable, to help us design for the human systems. But the, you know, the Curiosity is just a few watts of power. It doesn’t really need very much power. Humans are going to need kilowatts of power. So, it’s — once you put the humans in the system, and you start trying to run life support systems and, you know, just the level of safety requirements that — you know, you need to be sure. You need to have a Plan B and a Plan C. I always give my friends at JPL a hard time, because they’re robots. They don’t need food or water or bathrooms. And the human systems — the humans will need all of those things. So, there’s a whole new level of stuff that has to be thought about for the human missions, that the robotic missions never really had to worry about. It draws power. Once you have more power, you need more thermal control. Once you have more thermal control and more power, that’s more structural mass. So, these things tend to snowball a little bit. And that’s why our systems end up being much bigger than the robotic systems are. People always ask, “Well, why not just send robots then? Why not just send robots? Do we really need to send humans?” That is a debate that will rage for the ages. What the scientists will tell you is that the humans can do in a day what it would take the robots to do a year or more to do. So, yes, there’s a compelling reason to send the humans. The humans can make real-time decisions. The humans can fix things that break. When poor Opportunity got caught in a dust storm and the solar arrays were covered, there was nobody there to dust them off. So, unless you’ve thought through that and planned for that contingency, with the robotics, that’s the kind of thing that if a wheel gets stuck somewhere, the humans can get out and deal with that, whereas the robots can’t. So, I can understand both sides of the argument. I happen to work on the human spaceflight side, so I’m a little bit more predisposed to that side.

Host: [Laughter] Sure, but I think maybe you might have a better appreciation than most for maybe living on Earth and what Earth has to offer, and things that maybe people don’t consider when they think, why are we not on Mars right now? Let’s go to Mars. You’re like, no, it’s really hard, because there’s a lot of things that we’re doing right here on Earth that are just — we don’t even recognize — our conveniences are just — they’re, you know, I was thinking — one thing I was thinking about when you were talking about a journey to Mars in the distances and bringing things with you — I just did a road trip to Florida. It took me 17 hours. And yes, I packed the car full of waters and snacks. But I stopped for coffee, for a bathroom, for, you know, just to take a break, because I could. And I could get out of my vehicle, and I can kind of get more provisions, and I can use other facilities. And then I could get back in that vehicle, and I can keep driving. But that’s not — that’s not a luxury, for a journey to Mars. I’m sure you have a better appreciation than most for this.

Michelle Rucker: So, being from Alaska, I have a very good appreciation of this. So, the reason I’m from Alaska is because back in the ’50s, the U.S. government was trying to encourage more people to move to Alaska. They were trying to open up the economy there. And one of the challenges of getting to Alaska was it was really far away, and there weren’t a lot of gas stations on the way. And nobody could really carry that much gas, to get all the way to Alaska. So, they offered homestead opportunities for folks who were willing to set up gas stations. And my maternal grandmother moved to Alaska, set up a gas station near Palmer, and that’s why my family was in Alaska. So, for me, it doesn’t bother me at all, to think about eventually setting up way points between here and Mars, to refuel vehicles. I know some people are overwhelmed by the sheer difficulty of that. It’s hard, and it’s dangerous, and it is. But probably no more daunting than it was to my grandmother, moving to Alaska, with a couple of kids in tow, and setting up a gas station, out in the wilderness. So, yeah, it’s hard. But there are people here on Earth who are up for that challenge.

Host: You definitely have a better appreciation. It’s even in your family. Just working on this and thinking about Mars and all the challenges that have to be answered and thought about before we actually go there, but thinking about some of the things that are in the near future for Artemis, and some of the answers that we might get, some of the questions that we might continue to — that might continue to come up and that we might have to learn, what are you most excited about for this near future, going to the Moon and thinking about some of the things that we might be able to answer for a Mars mission there?

Michelle Rucker: I spent most of my career working with shuttle and space station, and those were really fun programs to work with. We were, you know, launching humans pretty often, and we were doing lots of interesting things. Going to the Moon is a whole different set of challenges. It’s some of the same challenges as — you still have to launch people. There’s still danger and risk, and things above that, but landing on the Moon, that’s a whole different set of challenges than going up to the space station. Working on the Moon, that’s a whole different set of challenges. To me, that’s the most exciting. It’s the unknown unknowns, the things we don’t know about. We learned a lot with Apollo, but those were very short missions. Being able to stay a little bit longer on the Moon, which is probably what we’ll need to be able to do for Mars, it will just give us a lot of information. We’ll learn what doesn’t work, and I think that is almost as valuable as designing things that you hope work. Knowing what doesn’t work is pretty important.

Host: That’s incredible. Michelle Rucker, thanks so much for coming on Houston, We Have a Podcast today.

Michelle Rucker: Thank you so much.

[ Music ]

Host: Hey thanks for listening, we have some bonus content for you at the end of the show so hang tight. First the credits. This episode was recorded on January 8^th, 2020. Thanks to Alex Perryman, Pat Ryan, Norah Moran, Belinda Pulido, and Jennifer Hernandez. Thanks again to Michelle Rucker for taking the time to come on the show. I hope you liked this topic, because there’s going to be a lot more. This month kicks off monthly episodes all about a Mars mission, we’ll call it “Mars monthly.” And over the next few months, maybe even a year, we’ll dive deep into the various elements we discussed with Michelle today.

Host: Last month, NASA released a new podcast: NASA’s Curious Universe. Our universe is a wild and wonderful place, and in this podcast, you’ll join NASA astronauts, scientists and engineers on a new adventure each week. Take a listen.

Padi Boyd (Host): Before an astronaut ever sets foot aboard the space station, they have to train somewhere you might not expect.

[Deep plunge/cannonball splash sound]

Padi Boyd (Host):This isn’t just any old swimming pool, it’s the Neutral Buoyancy Lab, located at NASA’s Johnson Space Center in Houston, Texas. This special pool contains 6.2 million gallons of water, enough to fit nine Olympic-sized pools inside. It’s where astronauts like Nick come to train.

Nick Hague:So, the pool is this gigantic pool. It’s 200 feet long. It’s 100 feet wide, and it’s 40 feet deep. It is enormous. It’s still not big enough to fit the entire space station in it, but it fits full-scale large chunks of the station so that we can practice. And that’s our training ground.

Padi Boyd (Host):The pool is where astronauts first get acquainted with the armor that protects them from space, their spacesuit! And that can be its own challenge. First thing. You’ve got to suit up. It can take about 45 minutes and the assistance of multiple suit technicians to get the suit on — checking to make sure that every piece is fitted and working properly, from the helmet locking into place to the gloves fitting around every finger.

Nick Hague: You have to learn how to use the spacesuit, because it’s not like wearing clothes. It’s, constraining, and it limits some of the things you can do. It’s fatiguing because of the pressure of having it stiff, and so you have to learn how to use it, and that takes hours underwater, getting to know your spacesuit.

Padi Boyd (Host):Once you have the suit on and it’s been double, and triple checked, you can prepare to enter the Neutral Buoyancy Lab. Even though you’re not out in space just yet, the pool will simulate what you might feel once you’re out there. Why? Because being underwater simulates weightlessness.

Nick Hague:The Neutral Buoyancy Lab is there to train us, because that’s one of the places or one of the ways that we can try to simulate being weightless. So that idea of neutral buoyancy.

Padi Boyd (Host):It’s called “neutral buoyancy” because when you’re in water and you don’t sink but also you don’t float, you’re completely neutral. It’s like you’re “hovering” in place.

Nick Hague:And so, it feels as though I’m weightless and I can maneuver myself around the outside of the space station and have the experience of working in a weightless environment. And so, we’re constantly trying to balance out the weight of an object with its buoyancy so that things just float in front of you.

Padi Boyd (Host):Weights and flotation devices are carefully combined to let astronauts feel what it’s like to be weightless in space. When an astronaut is training in the pool, their backpack — the Primary Life Support Subsystem — is filled with air they can breathe and instruments that monitor their health.

Nick Hague: You’ve got to get everything straight because once you go underwater, that’s all you’ve got are the tools you took with you. You’re going to be down there for six hours.

Padi Boyd (Host): That’s about the amount of time it takes for a spacewalk in actual space. Once you’re in the pool, waterproof instructions are attached to your arm, and you rehearse the spacewalk as if you were doing the real thing.

[NAT SOUND of TRAINING: “Alright, Nick, before you get started on that… If we could just… help me guide that out… much appreciated.”]

Padi Boyd (Host): The whole time, a team of people is watching every movement of your practice spacewalk. They monitor the pressure inside of the suit and the temperature. And the test director is making sure that the whole process is going according to plan.

[NAT SOUND of TRAINING: “Good teamwork there. Exactly…” “So, I need to float a little bit higher on this end… alright, OK, so that’s good alignment.”]

Padi Boyd (Host):Trained scuba divers guide you around a replica of the outside of the International Space Station.

[NAT SOUND of TRAINING: “yeah, looks good here. Yep, we’re aligned down here.”]

Nick Hague: Having this full-size mock-up of the space station underwater allows us to, to essentially memorize where every handrail is, where every handhold is, and if I’m going to work in a particular location, on orbit, I will have seen that and understand that location on the ground.

Host: If you liked this clip, you can check out the full episode at NASA.gov/podcasts. Curious Universe is right at the top. Make sure you subscribe to get the latest — they have a new episode coming out on Monday. Thanks for sticking with us to the end. Give us a rating on whatever platform you’re listening to us on and tell us how we did. We’ll be back with a new episode of Houston We Have a Podcast next week.