Back to Top

Tap into the experiences of NASA’s technical workforce as they develop missions to explore distant worlds—from the Moon to Mars, from Titan to Psyche. Learn how they advance technology to make aviation on Earth faster, quieter and more fuel efficient. Each biweekly episode celebrates program and project managers, engineers, scientists and thought leaders working on multiple fronts to advance aeronautics and space exploration in a bold new era of discovery. New episodes are released bi-weekly on Wednesdays. 

Orion Spacesuit Engineer Kirstyn Johnson discusses the internal systems of the Orion spacesuit.

Some of the internal systems of the Orion Crew Survival System suit are similar to previous spacesuit systems, but new features and systems have also been added as spacesuits have evolved for deep space missions. In the second segment of a three-part series on new spacesuit design, Johnson highlights the engineering design challenges of developing spacesuits that accommodate women and men on long-duration missions.

In this episode of Small Steps, Giant Leaps, you’ll learn about:

  • The magic inside the Orion spacesuit
  • Challenges of designing the new waste management system
  • Building spacesuit hardware for each gender


Related Resources

Orion Spacecraft

Orion Suited Crew Testing

Astronaut Spacesuit Testing for Orion Spacecraft

Winners of Space Poop Challenge Receive $30,000

Episode 18: Orion Spacesuit Design (Small Steps, Giant Leaps Podcast)

APPEL Courses:

Requirements Development and Management (APPEL-REQ)

Human Spaceflight and Mission Design (APPEL-HSMD)


Kirstyn Johnson<br /> Credit: NASA

Kirstyn Johnson
Credit: NASA

Kirstyn Johnson is a Spacesuit Engineer at NASA’s Johnson Space Center (JSC) working in the Orion Program. As part of the team developing the launch and entry suit for future Orion missions, she focuses on the hardware that assists the crew in combating negative physiological effects brought about by the spaceflight environment. Prior to working at JSC, Johnson worked at BioServe Space Technologies and supported the launch and operations of payloads on the International Space Station. She has a bachelor’s and master’s in aerospace engineering sciences from the University of Colorado Boulder.



Kirstyn Johnson: That’s why this line of business is fun, because you do a lot of the engineering side, but then also doing the touchy-feely stuff that working with humans and putting hardware on humans brings along with it.

You’re developing a suit for internal functionality and fit, but then you’re also making sure that everything outside, they can operate it in those different scenarios.

It was awesome to hear the crew themselves, after they tried it on and did that evaluation, of like, “Hey, we should try this. This might work a little bit better.”

Deana Nunley (Host): You’re listening to Small Steps, Giant Leaps – a NASA APPEL Knowledge Services podcast featuring interviews and stories, tapping into project experiences in order to unravel lessons learned, identify best practices and discover novel ideas.

I’m Deana Nunley.

We’re continuing our series on the design of new spacesuits for future missions, taking a closer look at features of next-generation spacesuits as well as technical design challenges.

Kirstyn Johnson leads the design of the internal systems for the Orion spacesuit, and is our guest today on the podcast.

Host: Kirstyn, thank you for joining us for the second segment in our series on spacesuit design.

Johnson: Yeah, I’m glad to talk with you today and follow up with what Dustin talked with you about on the last podcast. So, I’m glad to add to it.

Host: Yes, in our last episode, Dustin Gohmert gave us an overview of the Orion spacesuit. Today, we’re talking about the magic inside the spacesuit. What are the internal systems of the spacesuit that you’re working on?

Johnson: Yeah, so for any space buff out there, there’s some of these systems that are commonplace and used in different spacesuits historically. So, I kind of work and develop all of those — what we call internal suit systems. The most common ones are a liquid cooling garment that the crew wears to keep themselves cool whenever they have the suit on.

There’s an orthostatic intolerance garment that helps with changes in the body physiologically, after being in a microgravity environment for so many days. Those are ones that we’ve had since Shuttle and we use. We also have a thermal control valve that goes along with the liquid cooling garment, and then a communication cap assembly or comm cap that the crew wears.

Now there is one more system that is new to our launch and entry suit, the OCSS suit, that we are calling off-nominal waste management system. That one is more of a special one that’s new based on Orion’s concept of operations in the six-day cabin depress scenario. So that’s one of the items that I’m spending a lot of my time developing to be part of our suit hardware repertoire going forward.

Host: What are some of the biggest challenges with the waste management system that have required you to work your magic?

Johnson: Yeah, so I think Dustin talked about this a little bit in the last podcast, but like I was kind of saying, this is the first time we’re really had a waste management system for any recent launch and entry suit. So, the set of us engineers that are working on it now don’t have that experience to build off, I guess. We can look back historically and see that back in Apollo and Gemini days they had a similar requirement for, “Hey, if our vehicle, when we’re far away from Earth, if we experience a cabin depress event, so we basically lose all the atmosphere inside the vehicle, how do we keep the crew safe?”

That means climbing into your launch and entry suit, which is another pressurized low environment that can contain the crew until they get back to Earth. Well, part of containing the crew inside there for up to six days or 144 hours is our, I guess, design requirement.

Part of that is you have to obviously feed them. Then, of course, with feeding someone comes the other end of it, whatever waste that they expel from the nutrition that they consume. So, some of the challenges are just figuring out how you do that in such a confined environment.

Dustin might have alluded to these suits that we’re using for Orion are going to be custom size. So how do we also kind of custom fit a waste management system for each of these crew to wear up to six days that is comfortable against their body? And I guess that’s both a physiological comfort and a psychological comfort, something that minimizes damage to the skin and also gives them confidence that they can use it over that six-day duration without any loss of functionality.

Then finding ways to test it is also a big challenge that we have here onsite, and maybe not a challenge as much as getting people used to the idea of, “Hey, this is going to be part of our system now.” How do we change our lab operations and get our suit technicians and engineers used to talking to folks and talking to crewmembers about this kind of hardware?

It does get to be a little bit of a sensitive conversation as you get down into the nitty-gritty of how the waste management system fits on someone’s body. So, we’re still getting used to understanding how we operate in that sense.

Host: You mentioned when you talk about the nitty-gritty, that it does get just a little bit sensitive. Without asking you to do anything that’s particularly graphic, I’m just curious if you could tell us a little bit more about maybe some of the obstacles you face, and maybe some of the details of how you’re trying to make these systems work.

Johnson: Right. Whenever you’re talking about a waste management type system, there are two different functions you have to control, fecal output that the crew might have and the urine output. The urine output is a little easier because you’re dealing with a liquid similar to water, and our mindset of how we handle any urine output from the crew is let’s just get it out of the suit, get it away from them to minimize any skin damage over the course of six days, and anything that wetness could cause if it were to be retained in the suit.

So, our goal there is can we use some type of what we call a body interface to help remove that urine away from the body, use some tubing to get it outside of the spacesuit. Once it’s outside the spacesuit, then using the dump overboard line or the vent line on the Orion vehicle to expel it to space.

It sounds easy enough. It’s a similar design to what Apollo did. I think that some of the key issues we have to work around is what is that body interface part. Over the course of six days, like I mentioned earlier, you have to worry about skin wetness and some of these other medical issues that can pop up with having an area that’s constantly exposed to moisture for that long of a time. So, we’re working a lot with medical folks out here to try to deduce what’s the best way to keep the crew healthy in this situation as we try to remove urine from the suit.

We’re also dealing with different types of crew, not only different genders, but different body sizes. So, understanding how all of that hardware fits as perfectly to them as possible, to help remove as much liquid out of the suit as possible, to keep them healthy and safe.

Then on the fecal side, this one is more complex in terms of how we try to keep them healthy, but then the design is much more simple. We’re kind of limited to keeping any fecal matter that’s expelled inside the suit, because you could have a – to put it nicely – a range of viscosity that you’re having to deal with, and developing a system to that without putting too much perturbation on what the suit design is. It’s one of those balances that we have to play with.

So, our goal is really just to keep it inside the suit, not impinge on the suit design for this off-nominal situation that we’re hoping will never happen in the first place, and then trying our best to protect their skin and other areas from getting infected over the course of six days. Of course, part of it is making sure that whatever they put into their bodies, can we try to minimize the output that would be accumulated and come out as fecal matter. That’s not necessarily our hardware, but it plays into what we have to deal with on our end.

So, as part of this, too, we did do a Space Poop Challenge. That’s what it was called. It was a crowdsourcing challenge that we did back in 2016 to try to generate ideas of what exactly this hardware would look like. We had some notional ideas of what we wanted to do, but because it’s been a while since anyone here at NASA has really looked into how do you design hardware to go inside a spacesuit, we wanted to make sure we weren’t missing anything from another industry, whether commercial or military or the medical industry. Was there something else out there that already existed that we could take and adapt slightly for our use? So, we did that to try to understand if we were missing anything.

We got a lot of interesting replies back from folks and a lot of people that were engaged. I think we ended up getting over 5,000 responses of ideas coming from folks, and it was great to see how everyone was trying to innovate, to help us in this particular type of hardware development.

Host: And you received those responses from people who participated in that challenge, and I know that you’ve been working now for several years on this. How would you say that the development of the waste management system is coming along at this point?

Johnson: It’s coming along very well. Of course, being the type of person I am, I wish it was going a little faster, but it’s going at the pace it needs to, to make sure that everyone buys into our design, and engineers and crew are comfortable with using it going forward. Like I said earlier, it can be slow at times just because you’re getting everyone on the same page and getting folks comfortable with how it plans to operate and what frank discussions you need to have on how it’s going to interface with you.

It was two years ago now that we did our first evaluations with what I referred to as those body interfaces, the part that adheres to your body, and that’s how we’re going to do it, use an adhesive to stick these routing mechanisms on your body to help pull the urine away and out of the suit. We did an initial evaluation with engineers and subjects to say, “Hey, here are some of the components that we’re thinking about adding to our system. Do you have problems with using this? Do you think you’ll have any functionality concerns? Do you think you’ll have any really psychological concerns with using this in this type of scenario?” So, that was our first test to say, “OK. We have a path that we can go down, to use this hardware as part of this system,” and slowly developing it and incorporating it into our system.

So, last fall was the first time that we did a urine functionality evaluation in one of our Orion launch and entry suits. So, what that name basically is saying, we had a test subject climb into one our suits, pressurize it up to 4.3 with all of this waste management equipment on and said, “Hey, pee into it. See what happens,” which is always an interesting test when you have suit technicians standing around and engineers standing around.

We let the test subject put their sunshade down, so you can’t see anyone else and they can’t see your expression, because going to the bathroom is something that you don’t typically do with people watching you. But it’s kind of the one inherent way to really test this and make sure from a human factors perspective there’s no concerns with how it feels on your body, that there is no urine going to back up and cause any pressure issues internal to your body. So, we’re slowly getting more folks in to do those tests and getting more folks comfortable, and hopefully we’ll get crew in here soon to also do that test as the end users of this product.

Host: Let’s talk about other internal systems of the Orion spacesuit. What are some of the interesting developments that have captured your attention in designing the spacesuit?

Johnson: With some of the other items like the liquid cooling garment and the orthostatic intolerance garment, similar to what we’re doing with the suit, we’re making a very concerted effort from the onset to make products that are good for the range of crew that we could have. One of the main drivers in the Orion Program is making sure that the hardware can meet the first to 99th percentile of body sizes.

It gets a little confusing if you break down what that first to 99th means exactly, but we’re basically making a statement that we want to be able to accept a diverse set of crew and have them be able to fly, as opposed to some past vehicles, whether U.S. or Russian, that have restricted size or height because of the size of vehicles that we developed. So, we’re being all encompassing with Orion, and part of that is the first to 99th, but also both genders, female and male, and making sure we incorporate that from the get-go.

It is interesting to see how different females and males end up getting — I guess how you build hardware for each gender. Neither one is bad. It’s you’re built differently for different functions. It’s cool to see what certain things you have to pay attention to based on what person you’re dealing with. So, making that concerted effort from the onset is very cool.

One of our hardware items, the orthostatic intolerance garment — imagine a really tight pair of pantyhose or compression stockings that you wear. The idea is that that garment helps with what’s referred to in the medical world as orthostatic intolerance or an inability, I guess, when you stand up, to maintain your posture without fainting or having a sudden drop in blood pressure.

Some of our crew experiences that after they get back from a microgravity mission due to a fluid shift that occurs. So, once you lose that 1g environment, once you get to space, your body suddenly realizes, “Hey, I don’t need this excess fluid that’s in my bloodstream to maintain my blood pressure.” So, you start to get rid of it. You start to pee it out, essentially.

But when you return to Earth, after your two- or three- or four-week mission, you need that fluid back. So, sometimes the crew does fluid loading to try to retain it, but it doesn’t get you back up to your nominal state. So, your orthostatic intolerance garment helps squeeze your limbs to minimize the volume that you need in your blood vessels to help maintain blood pressure at a more normal level and help maintain your heart rate to prevent this orthostatic intolerance. So, if you stand up and have to move around, you’re not fainting or having issues in doing whatever you need to do.

So, part of developing this garment that has to remain tight on your body is, well, given a crew of different body sizes, no matter what gender you are, how do I get something that’s supposed to be tight fitting on, when you have hips, depending on the size of your stomach, depending on the size of your legs. So, trying to accommodate that range of sizes is always a challenge for that type of garment, and that goes right back to the suit, too. So, that’s why this line of business is fun, because you do a lot of the engineering side, but then also doing the touchy-feely stuff that working with humans and putting hardware on humans brings along with it.

And then the liquid cooling garment, we have more heritage in this. But to provide the best function, the liquid cooling garment functions by using a set of tubes that route inside of a garment. We run cool water through those tubes, and those tubes sit on top of your skin. Now to get the best bang for your buck in terms of cooling your skin and cooling your core, that garment needs to be as tight to your body as possible.

Of course, as we know, torso shapes and sizes are different across genders and just across people in general. So how do we work to make sure that garment is going to fit everyone as best as possible and provide the best outcome in terms of cooling during a mission? So, working through all of those details is a challenge, but a fun one, and getting comments back from crew and tying to work through how we solve it to meet everyone’s needs is what keeps us busy day-to-day.

Host: When you’re up against these spacesuit design obstacles, some that haven’t been faced before, what’s your thought process or your workflow for digging in until you find a solution?

Johnson: That’s a great question, and one that I probably will continue to figure out through

the rest of my engineering career. I’ve found, at least with this waste management system, the best way that we kind of come up with solutions is, honestly, to test an idea and see what we come up with. Because our testing uses engineering or crew test subjects, we frequently get input from them. It’s kind of a group approach at that point of, “Hey, we both use this. Can we collaborate to see how we would change the design to get a better function out of it to meet comfort and functionality that we need to?”

So, testing always comes up with the best solutions. I remember when we would do the crew evaluations for these body interfaces back a few years ago. It was awesome to hear the crew themselves, after they tried it on and did that evaluation, of like, “Hey, we should try this. This might work a little bit better, prevent leakage maybe in this one area.”

So, it would be wrong for me to say I do it alone, because there are a ton of folks that help me with this, whether they’re test subjects or other folks on my team that have different viewpoints, just based on gender and your own life experiences. So, a lot of that is just talking to folks who worked through via tests.

Host: You mentioned several aspects of the internal suit design where gender diversity has presented challenges. What other fascinating observations could you share about designing spacesuits for women?

Johnson: There’s definitely a ton out there. I think since we do our day-to-day job in this, there are so many that just don’t come to mind. But going back to the waste management system, it’s amazing how many anatomical differences, when you go down to the area that deal with ways that change how you function with – or how this type of system functions.

So, for the body interfaces, you obviously have two different anatomies you’re dealing with. For the male side, it’s something we’ve typically worked through before. It makes males cringe whenever they hear it, but using external condom catheters to help remove urine from the body. It especially makes the males cringe when you say that it has adhesive on it to help it last for six days.

But on the female side, it’s almost going to look like a menstrual pad with a little collection well. They’re made out of silicone, so they’re flexible and it’s not an absorbent type material, but it also uses adhesive to stick on the body.

One interesting thing, besides the hardware design itself, is understanding how you interact with the people of different genders. I got this kind of warning ahead of time before doing our crew evaluations that males are typically much more cautious about speaking on this type of subject, for whatever the societal norms are that tell them they don’t want to typically talk about this type of thing. But it was also cool on the other side to see females open up about this type of subject because, historically, they haven’t had great ways to help with their style of waste management, if you want to say, whether it be for what’s used inside suits typically or even what’s used in the normal toilet that’s used either on shuttle or station or what will be used on Orion. So, understanding how you portray the hardware as a message to the crew has been one interesting thing.

One thing that commonly comes up, too, on both sides is how do you deal with menses on the female side in terms of this waste management system. It’s an area that we’ve had to broach and talk with our medical folks out here because a lot of this detailed medical stuff doesn’t get talked about in the general public. Sometimes it’s a taboo subject that people don’t like bringing up, but it’s a great question of how do we protect females and the range of bodily functions that are normal to them.

So, we’ve designed our system to help accommodate that specifically, not knowing what our crew – what age our crew will be and if other medications are being taken to help prohibit or stop the menses flow that females could experience. So, accommodating for that range in bodily functions is something that we don’t talk about, but is definitely a part of our hardware design.

Host: I suppose that makes everything just a little bit more complicated when you’re having to think through all of these various functions, and you’re also trying to get a spacesuit that actually fits the body in the proper manner so that there is this comfort/tolerability that the astronaut can experience.

Johnson: It does, 100 percent. And kind of as third to those two items you just brought up, it’s also the human factors. How well can they use the devices outside the suit — valves and other items that go along with this system? How well can they actually operate it when they’re in a pressurized suit?

So, you’re working on developing the internal suit system for functionality, but also fit. You’re developing a suit for internal functionality and fit, but then you’re also making sure that everything outside, they can operate it in those different scenarios. So, it’s going to be fun.

We’re actually coming up on our Critical Design Review for our suit system, where we essentially take it to our stakeholders and say, “Hey, here is the design we’ve gotten, and here is our plan for certifying the design to make sure the range of scenarios we can see during a mission, this hardware is going to be able to meet that.” So, us planning out what that certification test series will look like is kind of fun, because this is your final, “Yes, this is the design we plan to fly. Is it going to work,” and figuring out what test subjects we need to participate in those evaluations to prove it out. It’s going to be a fun time to get everyone’s buy-in on that design, and prove to folks that this hardware is useful for crew going forward.

Host: Over these past few years, as you’ve worked the intricate details of designing internal systems of a spacesuit that a crewmember could potentially wear for up to six days straight, have you developed a heightened appreciation of astronauts?

Johnson: Yes, definitely. That can’t be said enough. And not even from the suit perspective, but just in general on hearing these crew members speak at different functions and design reviews and different events, understanding how they have to cope with these different scenarios that we’re putting them in, like the six-day cabin depress scenario, hearing them talk about themselves almost in the third person of, “Yes, if I were up in this situation, here is what I would want.” It’s a situation that is not ideal to talk about, but one you have to be frank about and knowing how you would expect crew to cope and handle it and how to react.

So, for their mindset to stay focused and be able to talk to someone logically about that event and not in an emotional perspective is fascinating and frightening to me. I would like to say I could do it, but it’s just a whole other realm once you fly and have to train for something like that. I most definitely have a different level of appreciation for them, and knowing the nitty-gritty of how this vehicle works, and seeing it through the design process of what has failed along the design process and how we’ve gotten comfortable with that, and knowing that they have to get comfortable with those functions and development process to feel comfortable going forward and flying in that vehicle.

Host: So just as a reminder, could you explain why we talk about six days of possibly being in the spacesuit?

Johnson: Yes. We do kind of gloss over that a lot in our day-to-day here. It’s become kind of a notional term on our end. We call it the 144-hour scenario. The 144 hours or six days is derived from certain orbital trajectory scenarios that Orion could go on in future missions.

The idea is if Orion is going to launch from Earth, do a trip around the Moon or do multiple trips, what is the quickest — or I guess what is the longest duration that it would take for that vehicle to return if something were to go wrong mid-mission. So, we look at when is the last trajectory burn that they do, and when that’s complete, if something were to go wrong at that instance, it could take up to six days for that crew to be able to return back to Earth, just based on the orbital trajectory they’re on.

So, it could be – if this event were to ever happen, it could be one day. It could be 46 hours. Or it could be up to 144. So as engineers, we really like design requirements. So that 144 hours gives us a stopping point, saying our hardware needs to be designed to last up to this long, no more, nor less. So, if we can design it to that, then we can design hardware to meet that specific function.

Host: This has been really fascinating. Kirstyn, thank you so much for being our guest on the podcast.

Johnson: Of course. I’m more than happy to talk with you today. It’s always fun talking about suits and some of this waste management hardware.

Host: Links to topics discussed during our conversation are available at, along with Kirstyn’s bio and a show transcript.

On the next episode, we’ll conclude our series on spacesuit design with a discussion of advanced spacesuits for extravehicular activity.

We invite you to take a moment and subscribe to the podcast, and tell your friends and colleagues about it.

If you have suggestions for interview topics, please let us know on Twitter at NASA APPEL, and use the hashtag SmallStepsGiantLeaps.

Thanks for listening.