From Earth orbit to the Moon and Mars, explore the world of human spaceflight with NASA each week on the official podcast of the Johnson Space Center in Houston, Texas. Listen to in-depth conversations with the astronauts, scientists and engineers who make it possible.
On Episode 413, NASA’s International Space Station Program Manager Dana Weigel and Director of the International Space Station and Commercial Spaceflight Divisions Robyn Gatens reflect on more than 25 years of continuous human presence aboard the International Space Station and discuss how the orbiting laboratory is paving the way for Artemis, the Moon, and eventually Mars. This episode was recorded December 3, 2025.
Transcript
Joseph Zakrzewski
Houston We Have a Podcast. Welcome to the official podcast of the NASA Johnson Space Center, Episode 413: Low Earth Orbit and Beyond. I’m Joseph Zakrzewski and I’ll be your host today. On this podcast, we bring in the experts, scientists, engineers, and astronauts all to let you know what’s going on in the world of human space flight and more.
For more than 25 years, humans have lived and worked aboard the International Space Station, a remarkable feat of engineering, international collaboration and human perseverance. Since the beginning of continuous human habitation on November 2, 2000 the International Space Station has not only been a home in space, but also a laboratory, proving ground and training platform that continues to shape humanity’s journey beyond Earth.
Today, we’re joined by two leaders who know the station inside and out, Dana Weigel, NASA’s International Space Station Program Manager here at Johnson Space Center in Houston, Texas, and Robyn Gatens, director of the International Space Station and Commercial Space Flight divisions at NASA Headquarters in Washington, DC. Dana and Robyn have dedicated decades to NASA helping to design, operate and grow the International Space Station Program, while fostering the partnerships that keep it thriving.
In this episode, we’ll reflect on the history and evolution of the International Space Station, discuss the critical roles of partnerships, both international and commercial, and explore how the station is paving way for Artemis, the Moon, and eventually Mars.
Let’s get started.
Joseph Zakrzewski
Dana, Robyn, welcome back to Houston We Have a Podcast. I’m excited to talk to you about today’s ISS 25th celebration, and everything that it encompasses, but it’s great to see you and again, welcome back.
Dana Weigel
Thank you so much. Happy to be here.
Robyn Gatens
Thank you. It’s always great to be in Houston.
Joseph Zakrzewski
Looking at your history with NASA, your careers with NASA and for you, Dana, we’ll start with you as the station program manager, to be the manager at a time like this, celebrating 25 years of continuous human occupancy at the International Space Station. What has that enhanced your role? How has that impacted your role as program manager?
Dana Weigel
It’s interesting. Let me, let me just back up and talk about kind of what I see is program management. You know, it’s obviously leading a very large, complex team. There’s a lot of elements to Space Station. We tend to think of Space Station as just the spacecraft itself that’s orbiting, but it’s really that and a lot more. We have all of the commercial cargo vehicles and all the launches that it takes to resupply it, sparing space suits, payloads, research technology, and then also the US deorbit vehicle that we will eventually fly at the end of station’s life. And so it’s, it’s a really complex campaign. It takes a whole collection of NASA team members across different NASA centers, commercial industry partners, international partners, to collaborate and make space station happen. And so when I look at it and I say, You know what? What does it mean to manage this program successfully and stay continuously crewed, it’s a joint effort. It’s an across the globe effort. We’ve had challenges throughout the years, and we’ve overcome them because of the partnerships and the capability that we’ve kind of built across the globe.
Joseph Zakrzewski
And that’s you hit a lot of key buzzwords that I’m excited to dive into with you and Robyn, especially when it comes to partnerships and the teamwork that goes behind this, and being in a fortunate position that I am here at NASA to work with you and the International Space Station program and help out in multifaceted areas, in the communications roles, it really is that team, that pyramid that you see that culminates into the International Space Station.
For Robyn, for you, how long have you been with NASA and for you, as your role as both the director of the International Space Station and Acting Director of the Commercial Space Flight division. How does that coincide with each other, and how does that enhance what Dana, the program and the overall team that we’re going to dive into accomplishes with the International Space Station?
Robyn Gatens
I began my career at NASA 40 years ago on the International Space Station Program. Back then, it was Space Station Freedom, and I started my career in Huntsville at Marshall Space Flight Center, working on the early design of the life support systems that we’re now flying. And so to be able to spend 27 years in Huntsville, and then since 2012 I’ve been in Washington, DC, at headquarters has just been an incredible, you know, journey, and I never could have plotted that out or predicted it.
My role now, I started as an engineer, and now my role at NASA headquarters as director is more one of overall policies, strategy and direction for the program and and for ISS and commercial LEO, it really encompasses LEO right from Space Station today to space stations of the future. And how do we, how do we build a strategy that makes that transition so that we continue our work in LEO? So I work a lot with NASA leadership there in Washington, our stakeholders in the administration, in the executive branch and in Congress. Do a lot of briefings, a lot of it, you know, doesn’t sound very glamorous, but it’s a more, I guess, strategic role. Yes, I keep up with station operations so that I’m able to answer questions about that and communicate about that. But that’s, that’s kind of my job.
Joseph Zakrzewski
It’s amazing again to see where we’ve come again with 25 years of continuous human presence aboard the International Space Station. And this is where I kind of want to walk down memory lane a little bit with you two and kind of go back to those early days of the space station program, and what your roles were then, in shaping what is the station today. When you look back, what was it like to be in those roles that you had? What was it like to be a part of something this ambitious and this exciting moving forward, because when that first element went up in ‘98 and then the continuous human presence that we talked about that was grabbing headlines all over the place, and I’d love to know what your perspective was back then, knowing what you were accomplishing, especially now, 25 years later, getting being able to look back on it.
Dana Weigel
You know, you mentioned early ‘98 and it just so happens that the very first mission I ever worked was the first module that we launched, Node One, and that was a STS-88 or the 2A mission. I was an EVA instructor and flight controller, and so that was my first real exposure being part of the station mission. What struck me is the complexity and the intricate nature of what it took to put station together. I was there for all the assembly and in Mission Control. So I spent the early part of my career kind of putting the vehicle together. I was the lead on the 11A mission. We brought up the P1 truss. And what stands out to me that really illustrated like how complex it was to put it together is we had we had some space walks and we had some robotic work. We moved the mobile transporter for the first time to a certain position, and we bashed into something, and had to send the crew out to figure out what it was. And it turns out we hit the UHF antenna. It was stowed on the truss because someone had changed the assembly sequence. We were supposed to have deployed it before we moved the mobile transporter. So it was a little bit scratched up, but we were able to get it deployed, and we were able to kind of save the mission and carry on. But just really tiny changes were really impactful. So it’s pretty impressive to me that we were able to successfully assemble it. I did move on to be a flight director, and I actually finished out my work in Mission Control with the completion of station assembly. So pretty, pretty fantastic to be part of that from start to finish.
Joseph Zakrzewski
And Robyn, from your perspective, what were those early days like when you started being in those meetings, being in the planning process, the development of station, and then seeing those first components make its flight, and then the first humans making that permanent residence to begin that 25 year accomplishment that we celebrate.
Robyn Gatens
Yeah, in very early days, my job was to take very early life support hardware and play with it in the lab and figure it out and try to figure out which subsystems were would would work, you know, for design. So that was fun. Getting hands on experience is a great start for any engineer. From there, I worked my way through various technical leadership kinds of positions, system, overall system responsibility. I worked with our international partners a lot, with the Italians, because some of our life support systems ended up in the Nodes two and three, which they built. So I worked a lot with our international partners over the years. Went through a lot of redesigns, you know, that whole roller coaster and change in in how the station was managed. But it’s really satisfying. A lot of people don’t get to see their project ever fly, and to be able to see not only your project fly, but the entire space station assembly come together, and just the legacy now that we’ve built and that it will be leaving is just, what an honor.
One of the most standout moments, I guess I had, was we finally got our water processor built. And. I went to launch it, and got to go down to the launch. Was night launch on the shuttle, and we got to see it fly, which is always a thrill to see your baby go. And instead of toasting with, you know, with spirits, or wine or something, we had brought label bottles of recycled water to the launch, and we toasted with recycled water as the shuttle went up. So that was one of the moments that kind of stands out for me.
Joseph Zakrzewski
Those are incredible memories, those first memories of assembling the station and being a part of building the station. Now, as we reflect on the 25 years of continuous human presence in your mind, and Robyn, I’ll start with you on this one, how have you seen like anything that goes through a 25 year process? How have you seen the space station evolve and become what it is today, not just in terms of hardware, but the role of science, the role of partnerships involved and people wanting to be a part of what is an incredible piece of human history in the International Space Station. And I would love to see, or know from those early meetings and seeing that flight hardware go to what you’ve seen today. How have you seen that story and that arc of the International Space Station evolve?
Robyn Gatens
Yeah, from seeing, you know, designs on paper, to seeing it get built to, to get launched and put together, obviously, that evolution, but then just the advancements in the in the capabilities and how we’re using it, just increasing more and more in ways that we couldn’t have ever imagined. We say it’s more like a, you know, a test kitchen, right? We try this, and we try that, and we were able to do a lot with the station, and we’re just continuing to see, yes, we have our international, traditional international partners, but we’re also seeing more countries participate, which is exciting. We’re up to, I think, 117 countries that have participated in some way or another with an activity on station. So we’re literally coloring in the map of the world with folks that have done something on the International Space Station. So that’s really exciting. And then just to see the commercial evolution as well. You know, this is a jumping off point for, you know, commercial industry going forward in low Earth orbit, and we have so much more commercial capability.
I’ve also seen a tremendous evolution in our national lab. One of my roles at NASA is as the NASA liaison for the ISS National Lab, which is managed by CASIS, the Center for Advancement of Science in Space. And in the early days of national lab, they get 50% of the resources, the up-mass, the crew time to use for non-NASA use of the space station. And in the early days, it was a struggle for them just to fill that with projects. And now there’s users lined up out the door waiting to find and high impact quality research coming in from those users, as well as our other government agencies. So that’s really exciting, and it bodes well for the future.
Joseph Zakrzewski
And for Dana, and you get that front row seat as the program manager and your time as a flight director, EVA Officer, you saw a lot of this come to station and watch it grow physically in front of you. In your mind, how have you seen the station evolve?
Dana Weigel
I would say, you know, obviously the first decade we were doing assembly, we were heavily focused on putting the spacecraft together. It actually felt like the mission was doing spacewalks and just trying to figure out how to put it together. We spent the next 10 years really trying to figure out how to maximize what we could do for research. But you know, from my perspective, I think this last decade that we’re in has been well beyond anything I could have ever imagined. Like there’s an explosion of interest and creative ideas for how to use station. Who would have thought we’d do private astronaut missions? We’ve done four of them. They bring their own unique aspect with them, whether it’s the research they’re doing, they reach different communities than what we classically reach, different universities, a lot of different entities. And so the awareness about space and how to leverage it and use it and the excitement is well beyond what I imagine we’d be doing. There are people from different nations who have never had astronauts fly in space that have had the opportunity to do that through the private astronaut missions. It’s really exciting. The number of kids that we’ve reached in those countries who weren’t paying attention to space before. So to me, that’s really exciting. The the other areas that I think I didn’t really realize were so valuable about space, were in some of the the medical breakthrough areas, in manufacturing, in space, I think we’re really just scratching the surface of what we can do, and we’ve had phenomenal results, and those have really kicked in in this last decade. So we are just starting that exciting journey, which is why we’re so thrilled to have a future space station to carry on the incredible work in LEO.
Joseph Zakrzewski
And you brought up something that it was a perfect segue into those that research and what’s being done on station now, and hearing even just feedback from the astronauts and the videos and the broadcasts that are put out on all the various streams, and to hear their excitement of what they get to participate in, what areas of research are you most excited about, or have you seen and look to continue to grow aboard station, especially now in this 25th year?
Dana Weigel
It is hard to pick just one, but since you ask it that way, for me, it’s the it’s the medical breakthroughs. Looking at the impact, the direct impact that we’ve had on quality of life on Earth for everyone, right, not just for our own NASA purposes for exploration, to me, is incredible. You know, we have discoveries like, there’s a recent one that’s out there with cancer treatment, where, because of the work they’ve done on ISS, Merck has been able to evolve what had historically been a chemotherapy treatment through hours of an IV to get the treatment that’s now a shot. And so these advancements, whether it’s in drug delivery or in the types of things that we can tackle, it’s just been amazing. We 3D printed human retinas on board LambdaVision did that. Can’t do that on the ground, because they fall flat in a gravity environment. So it’s pretty incredible to look at what you can discover, what you can either test and learn and then apply on the ground, or what you can actually manufacture in space. And so I’d say medical would be my kind of most amazing era area.
Joseph Zakrzewski
And Robyn for you, what excites you about the research being done, especially in this in this prime as Dana is a decade of of international space station operations, and maybe even what we can look forward to as we continue to move forward with these breakthroughs in science and research.
Robyn Gatens
Yeah, I have to also echo, I think the medical is, is first and foremost in my mind as well. I think what we’ve learned is not just because of microgravity, but because of the harsh environment of space, is diseases progress more rapidly. Organs age more rapidly. You know, things just happen faster, and what that allows is scientists to study that and come up with potential therapies and learn at a more rapid pace, in orbit versus on the ground, and do that through not just studying the human body, but we can put.. mimic, whole human organs on, you know, a chip the size of your cell phone. It looks like heart tissues beating, or a liver cell or, you know, and study what happens. We’ve flown tumors and study what happens with tumors, and been able to see tumors metastasize and understand, you know, more quickly, which kinds of tumors are going to metastasize and that that is all you know, straight up benefits for humanity here on Earth. I think the- you know, there are things you can do in space that then bring back and you can improve a process on the ground, and then there are things that you can only do in space. And both are exciting to me, like these sort of advanced manufacturing things. Maybe we can help produce better semiconductor chips or optical fibers, or, you know, materials in space. And then there’s things that we can learn in the medical field. So we don’t know, we don’t know what’s next. We love to hear about the results. It’s my favorite part of any of our reviews, is when the scientist gets up and talks about what we’re flying and what we’re learning, and then we can help communicate it.
Joseph Zakrzewski
Microgravity certainly plays that role. And Dana you mentioned, with the retinas and gravity, having it fall flat so the unique environment is ripe for opportunity. Has there been a moment and to kind of put you a little bit on the spot, but is there a moment that you have found in this research, in the science, or even just in interactions that an astronaut might have on board with the experience of microgravity that might have surprised you or even created wonderment within yourself, of I didn’t realize we could do this aboard the International Space Station.
Dana Weigel
You know, I’m going to answer that by telling you something that, really, I think we understood from a physics standpoint, but until we saw it, we didn’t, we couldn’t really process what was happening. So this particular one is a, this was actually a serious anomaly that happened but, but it taught us a lot. We had a space walk EVA 23 where we ended up with water in the helmet. Luca Parmitano was out, and we ended up with water coming into the back of the space suit. There’s an inlet port at the back, and it kind of crawled up around a helmet vent pad and ended up on his head. What we learned from that is that our understanding about how the fluids would behave, how they would transfer, how they would move, were very much based on a one gravity thought process. It’s really hard to stop thinking that way. I mean, it’s what we see, it’s what we observe all the time. We had seen water flow in ground testing, and it would just shut down the fan of the ventilation loop. And so after we really took a hard look at that and realized this, this makes sense, that it wouldn’t really work this way. It was just a really good lesson about you’re in a really different environment, things really do behave differently. And for us as designers of spacecraft, and as we look towards the future, trying to carry those lessons and those triggers with us to really make sure, as we move forward and we design things and we look at things like fluids, which are going to behave differently, that we really factor that in. So for me, that is that is something that, yes, we understood physics could do that, but just because we’re so used to the the 1g environment, we hadn’t really predicted that the outcome would be very different in in microgravity.
Joseph Zakrzewski
Robyn, has there been a moment that has caught you by surprise or in wonder. Knowing you know on the ground, you’ve worked it out, you’ve had the meetings, you’ve had the backroom discussions, but to see it in action did anything maybe surprise you or create wonder in your mind, in station’s history, with the amount of research and hardware that has gone?
Robyn Gatens
Yeah, lots of lots of times when things have surprised us, good and bad, I would say, drawing from the life support experience. We designed our urine processor around ground testing. We distill urine and concentrate it, and we have to stop at the point where solids start to precipitate out, because then that fouls up the hardware. And so we’d done all that testing, we flew it, and guess what? On orbit, solids started precipitating out sooner than we had seen on the ground. And the reason was, astronauts are losing calcium more on orbit and so we didn’t think about that. We didn’t. It’s kind of a test like you fly situation where there’s more calcium in that urine, therefore we couldn’t concentrate it as much as we could, you know, so that all those lessons you learn, like Dana was saying, stuff just behaves differently on orbit and behaves differently when you put it all together than when you have tested on the ground.
But yeah, things that I guess in the research area that have surprised me, I continue to be surprised with just the new things folks are coming up with, the improvements and the ways to do research more effectively. I think we’ve gotten a lot better at it. We’re up to incredible statistic, which is 83% of our science objectives are being achieved through a project on the International Space Station, which is a really high outcome. So we’ve gotten quite good at doing the science and getting successful outcomes.
I guess another example would be how important food is. You wouldn’t think about it. You would think, you know, these are astronauts, they’ll eat whatever. But in one of my roles is, you know, kind of developing the not just the life support, but crew systems, I learned that food’s a big deal, and it is a big gap. We fly a lot of different pre packaged food to station today that we’re not going to be able to fly on a trip to Mars, and we’re going to have to produce food on the way, not just for nutritional but psychological value, and to combat, you know, a variety, you know, boredom issue as well. And so that’s been a surprise to me, that that has been such a kind of a big gap area that that we’re just now addressing.
Dana Weigel
It’s a huge part of the crew’s psychology and happiness, just like how you wouldn’t want to eat the same thing on the ground all the time. They don’t want to. The fun part is each crew is different, and so what they run out of on board is completely different. Someone wants to eat all the fruit and dried nuts, and we’re running out of that. Someone else doesn’t touch it, but all the desserts are gone. And so it’s, it’s interesting. But, you know, to play back to you mentioned kind of crew and their discoveries on board, one of their favorite things to do is grow plants. And I think there’s, there’s just a connection, by the way, the plants don’t droop right, so they look a little bit different, but they still want the same light and water. But, but that’s something that grounds them to something from Earth, so it’s exciting for them. So never have a problem with people volunteering to take care of the plants. The only problem we ever have is if we didn’t grow enough tomatoes or peppers to actually share with the crew, and we only take them home for the researchers. So that’s a- got to have enough for the crew to eat!
Robyn Gatens
Wasn’t there a missing tomato, or…
Dana Weigel
Some may been eaten, but, um, but that’s, that’s-
Joseph Zakrzewski
For research.
Dana Weigel
I mean, that’s an exciting part. There aren’t that many crunchy things with the food, right? So, having fresh food and being able to grow it is really important. For station. We can send things up periodically. We can send up fruit lasts for a short period of time with the delivery, for example. But for Mars, it’s really important that we learn to also grow food in addition to the pre-packaged food that that we provide today.
Joseph Zakrzewski
I’d imagine it probably delights you, like it does for me when you get and see the photos that come down from station, especially on major milestones, whether it’s a holiday or a birthday or someone celebrating a major milestone of time and space, the uniqueness of those products that astronauts can be creative with, whether it’s Space Station sushi or, I think I saw a cake made out of peanut butter and honey. So that is something I would love to get your perspective. You know, with the research and the hardware itself, there’s that uniquely human element, as if space station itself is its own character in its 25 year history of continuous human presence. How have you seen that resonate with the astronauts, with yourselves here on the ground, knowing that you know as the crew rotates and as people come and go on station, the station itself is always that warm… I don’t want to call it character or main character. It is the main character that allows all this to happen within her.
Dana Weigel
Now you kind of talked about fun with food. And there’s a whole range of, you know, amazing photos. So food becomes sport, and so that that’s kind of fun too. We were just to play on both the psychology and the question you answered. But M&M’s, catching those free flight in the air. You know, there’s all kinds of fun with food. You know, the crew creates a really interesting environment. They’ve got to make space station a home. We’re talking a lot about the work that we do on Space Station and the important things we do, but they’re living there all the time, and so they’ve got to make it a home. They’ve got to, they’re all living together too. So it’s a home and a family. So some of my favorite things are, like, around the time of the Olympics. You’ve probably seen a lot of the footage, but, you know, Suni on a treadmill, running along with a marathon, or the crew, you know, passing a torch around, and so they’re pretty creative. We’ve had chess boards that have been up there. We’ve had any number of favorite things. We’ve had a lot of musical instruments. Music is a kind of a big thing, not just listening to it, but actually people playing. And so I enjoy watching how they use space station to kind of create a community at an actual home, you know. So they get pretty creative.
Robyn Gatens
Wasn’t there a chef hat made out of a maybe a toilet insert?
Dana Weigel
They do some pretty creative things. There was a gorilla suit too. That was… fun.
Robyn Gatens
There’s been some costumes fabricated.
Joseph Zakrzewski
I’ve seen that gorilla video make the rounds a couple of times at key moments.
Dana Weigel
They also do a lot of special things with the flight control team on holidays, so a Santa suit has come out, and a lot of other things. So a lot of fun times, both between the crew on board and the ground.
Joseph Zakrzewski
And again, I encourage anyone listening to and watching to please check out the International Space Station on all the social channels. You can see a lot of that. And I think Jonny Kim recently posted a nice video of the whole crew having movie night aboard the International Space Station. So in addition to the incredible research and discoveries and the hardware done on board station. It is, it is a home.
And as the 25 years we celebrate now, we look forward to so much more coming in the future from the International Space Station. And in those 25 years, so much has evolved here, on the ground, on in station. What has what have you seen, technology wise, that’s evolved, that’s helped the cause for the International Space Station to prolong and to continue to advance science research and the human experience in low Earth orbit? Especially now, as we look forward to the future you talked about, you know, what can be developed for low earth orbit, but might need to be adjusted for a mission to Mars. How is that technology and research shaping the future of exploration missions? And Robyn, I’ll start with you on that one.
Robyn Gatens
I’ll do, I’ll do a piece of life support. I know Dana wants to talk about that too, because that’s a big one. We, you know, in the early days, you know, we had an open loop life support system that that did not recycle, and now we’ve evolved that one of the big challenges that we learned was actually removing carbon dioxide out of the atmosphere. And the crew was complaining about headaches when the CO2 levels were a little too high and and we had a lot of issues with our hardware, so we redesigned that, and now we have a system that we feel like, is Mars ready? Not just Mars ready, but the future space stations in low Earth orbit, or, you know, Gateway can use as well. And so we’re- that’s a success story in in the evolution of our life support system. We have we have work to go. We still want to be able to recover oxygen from carbon dioxide. We have tested technologies that do that before, but we’re not. We don’t have a mature system to actually recycle air. We’ve removed contaminants, but get that oxygen back is going to be important for reducing consumables on a trip to Mars. So that technology, I think we need to keep just and the reliability of it. We need to keep working on for station, and then we need to keep working on those technologies, using LEO as a test bed. Our human research, you know, we’ve, we’ve done a lot of work there as well to advance and reduce risk and develop countermeasures for human bodies and long duration exposure and microgravity.
Joseph Zakrzewski
Dana, how have you seen the technology evolve from those first construction elements to the first humans to begin the continuous human presence to today, because so much has evolved in 25 years for all of us, including station.
Dana Weigel
Yeah. You know, early on, we were flying an awful lot of consumables. Robyn mentioned open loop, but we flew a lot of gas, just in tanks. Shuttle was a big, a big help with that. Being able to transfer that over. And a lot of water. When you look at going to Mars, the further and further away you go away from Earth, the less you can carry, right? That makes sense. You can’t just have redeliveries of cargo. So high performance of life support systems, high reliability is really, really important. Some of our failure rates of our equipment is too high. Of course, we’ve got cargo deliveries. If you’re in low Earth orbit, you can send up a spare, but with Mars, you get one chance to figure out what you need to take with you, and you better have the right stuff right.
And so we’ve got these certain targets that we’re trying to hit, both for performance and reliability, so that we can get in the right box, so we can get to Mars. So station’s really been a test bed. So a lot of what we’re doing, yes, we need it for station, but the goal has always been use station to get the equipment to the point that we need for Mars. And what stands out to me is in the Water Recovery System, there was a lot of water that we flew and we spent when we first got our regenerable water systems up, there we were around 87% of water recovery. And then we really started pressing on redesigns and other technologies to fill the rest of the gaps. We’re at 98% water recovery right now. 98%! It’s really close to what we need for Mars. There’s some other trades we’re still doing to see. You know, how far should we really go? What’s the right balance there? But to me, just like the carbon dioxide, kind of hitting the sweet spot of what we think we need for Mars, even though we’re not all the way there with water, it’s incredible how far we’ve come. And of course, station reaps the benefit, because I don’t have to fly as much water. I can fly more research instead.
Robyn Gatens
And that plays into, yeah, we can support more crew, which, you know, can do more research. So it really is a win, win. Yes, for Mars, but also for what we can do in low Earth orbit.
Joseph Zakrzewski
It’s amazing to hear those percentages continue to increase as station’s activities continue to grow here over these last 25 years. And I just thought of it when you two were talking to just what the conversation of 3D printing of anything would look like back in 2000 to what it is today. You mentioned the retinas earlier. The tools might be needed. I think I saw some photos of metal printing that could be done to not only benefit station, but benefit what can come after that. I would love to switch gears just a little bit, because again, we are celebrating 25 years continuous human presence and it has been possible, and relied on thanks to international partners that have been involved with the International Space Station as well to both build and operate the space station. How these collaborations shaped the station’s success and those conversations and meetings and overall design to what it was, you know, starting off to what it is today?
Dana Weigel
The partnership has been critical to station. We’ve spent a lot of time today talking about what, what we’ve kind of done on the NASA side. So I’m glad you asked that.
You know, the Space Station was designed to be an integrated vehicle across five countries. Five primary countries. You know, the Russians provided propulsion. We don’t provide the propulsion. We provide power and the life support systems that perform at a pretty high level. Each partner’s brought something unique and contributed in unique way. The Europeans and the Japanese brought modules. They brought external payload facilities and capabilities that they brought cargo vehicles, both of them, and Canadian Space Agency, the robotic arm, they’re that they’re the masters at robotics, just like for shuttle. But the robotic arm, we’ve got a large arm, and then we’ve got a dexterous arm, and that’s been critical to doing maintenance and repair of station, to capturing cargo vehicles and to moving around payloads and other assets that we have. And so each partner throughout the design development into today’s operations has been really critical to our Success.
Joseph Zakrzewski
How have those conversations been for you, Robyn?
Robyn Gatens
Yeah, not only just the capabilities, but I think the experience that we’ve gained in and then jointly operating and doing missions together with our international partners has been a real learning experience, and those skills that we’ve developed and those relationships and how the missions get integrated. Those are, those are things we’re going to need to continue when we go beyond low Earth orbit to Moon and Mars. We’re doing it as a partnership. So we need to, you know, all of those systems we put in place and those agreements and how it all works, and the skills that we develop in as an integrated crew are going to feed forward for how we how we’re going to do it going forward, because no one country can afford, you know, to explore alone. We need to do it with our partners. And so it’s just a continuum from low Earth orbit out beyond.
Joseph Zakrzewski
And as the station has evolved and grown with these international partners, you kind of mentioned that no one country can fly alone, and the excitement of what lower Earth orbit in the international space station can bring, that introduces a new wave of partnerships with commercial partners coming on board and wanting to be a part of the excitement of the International Space Station. How do those commercial companies support both current station operations, as well as help push the station and themselves into the future?
Robyn Gatens
Yeah, we’ve, we’ve really brought commercial along with us from the very beginning, and that’s NASA’s philosophy, is we the government will do, you know, an invest where commercial industry isn’t quite ready, but we will bring commercial industry along with us. And then as they become ready and able to take over, then then we let them take over, we can be a customer of those services, and then we go on and do the next hard thing. That’s kind of our overall philosophy. So that’s what we’ve done with station. We’ve had commercial industry along with us, side by side and the capabilities have grown. We’ve got all these commercial facilities, scientific facilities on station now, or up to a dozen or so of those. And the those entities are really good at “Hey, I’m, you’ve never done science in space before I’m let me help you figure out what you’re trying to do and make it an actual payload. You know that’s going to work and deliver the results you’re looking for.” That’s what they’ve gotten really good at. And all of that is going to be important for the follow on space stations to have those commercial capabilities and that that same expertise, to make the- what the users want to use them for successful.
Dana Weigel
You know, I would add that it’s probably not apparent to many people, but two thirds of the resources that we get for Space Station actually go to commercial providers. So if you look at commercial cargo, Commercial Crew, I mean, those are, those are huge parts of what it takes to make space station successful. Private astronaut missions are kind of a new stepping off point and those are, those are pretty exciting. Of course, those are even more commercial than the services and the vehicles that we’re providing. So it has always been the goal to try to partner with commercial industry and find ways that are mutually beneficial. And I think we’ve been hugely successful, and we’re only seeing more growth and interest in those areas. And so I think we’ve created a platform, an infrastructure, a capability that that’s welcoming. And we have so many different ways now that we can partner with commercial industry, whether it’s in the research realm or flying additional people. And so we probably do a lot more commercially than what most folks really realize.
Joseph Zakrzewski
And on that note, that 2/3 number is fantastic to learn and understand, because how have those partnerships accelerated the International Space Station, whether it’s through research and design or through hardware and operations or through just discoveries that everyone can benefit from? And it sounds like that number continues to increase, but I guess, in your words, starting with you, Dana, how have you seen that firsthand expand the opportunities aboard station, especially as you mentioned at the top of these last 10 years, with everything happening and these opportunities available, it seems to have grown exponentially.
Dana Weigel
You know, if I step back and look at at how we started it, we we put a lot of effort into the early cargo capability development, using SpaceX as an example, the work they did with the Falcon 9 rocket and reusability, and the determination they had to drive down transportation costs was a game changer, not just for space station, but for the entire launch industry. You know, they kind of set the standard for lowering access to space, lowering transportation costs, which is still the largest cost. I mean that launching rockets is still expensive, but they driven that down substantially.
And then with the dragon, you know, really pushing into other uses for it. Of course, we use them for private astronaut missions, but they have done a number of their own human space flight missions, their Inspiration missions. And so I think what we see is through our initial support and investment for what starts off as kind of NASA purposes, the real hope in the goal is that there are spin offs and there are other uses. And that’s just one example, I think if you look at some of the medical and some of the other areas we’ve talked about, or Robyn’s example, with semiconductors, or some of these other fields, there’s great opportunity for similar mutual benefit, both with NASA’s overall goals, but also, what could really help blossom into commercial markets and commercial industries.
Robyn Gatens
For national lab, if you were a user in the early days, NASA would pay for your PI, your research, we would pay for your integration cost, and we would pay for your flight. Today, it’s been really exciting to see that the proposals we have coming in now for projects to fly through the National Lab, most have their research covered and their integration costs covered already through other investment, and we’re still providing the flight. But that’s a great trend. We’re seeing now private investment coming into play, and from the commercial sector interested in doing space research. So the demand keeps growing. There’s 80% of the projects that come through National Lab today are from the commercial sector. And so, yeah, it’s going to take a while for a lot of that research to become self-sustaining and now be able to pay for the transportation cost, which is, you know, a big chunk of the cost. But it’s really exciting to see some of the beginnings of that and that trend. We’re also seeing increased interest from our other government agencies in sponsoring research and doing more and more, some that have been with us for a long time, such as National Science Foundation, National Institutes of Health, but also some new agencies dipping their toe in the water for the first time, you know, like NIST [National Institute of Standards and Technology] and, you know, agriculture, USDA [United States Department of Agriculture]. So that’s really because we want this to be a whole of government ecosystem, as well as commercial.
Joseph Zakrzewski
And on that upward trend now looking forward for the International Space Station and the opportunities aboard it. What do you see as those key opportunities for NASA, for its international partners, its commercial partners, to work together and to continue to grow in low Earth orbit and beyond?
Robyn Gatens
Well, our plan is to actually build that partnership. Take the partnership we have today, and keep, keep extending it into low Earth orbit. We- our international partners who were partnered with today on your International Space Station. All want to continue working in low Earth orbit. They, they Yes. They want to go also with us to Moon and Mars, yes, but they also want to continue working in low Earth orbit. And then we, we have a number of commercial, private entities interested in building infrastructure capabilities and services in low Earth orbit and and so what we’re trying to figure out is, what is the role? What is that balance right? How much should we invest? How much is going to be coming in from the private sector? How can we best partner so that NASA can, and the international partners can continue to get what we want in a cost effective way? But also, you know, but in this new paradigm of commercially owned and operated.
Joseph Zakrzewski
And for you, Dana, how have you seen that that trend you mentioned the private astronaut missions, there’s more and more interest and excitement to go to the International Space Station? As program manager, that’s a lot of air traffic controlling you have to do because so many people want to come to join this orbiting laboratory. If you continue that trend moving forward, what are the opportunities that you see for NASA and its partners?
Dana Weigel
By the way, it’s a great problem to have. You know is humans, we all have common desires, the desire to explore, to discover, to see breakthroughs, to see improvements for life here on earth. You know, there’s these common threads. And it doesn’t matter what country you’re from, where you’re from, at the end of the day, there’s commonality. There’s similar intersections with commercial too. And so these, these interests that we have in space, and our understanding about how we can best use it and best collaborate, we continue to learn, we continue to grow. But it, it’s, it’s a multiplier, right? Those the ideas, and I think the real intersections that we have between commercial, international, and NASA objectives, they’re not, they’re not too different. And through the right collaboration and partnership, we can meet kind of all those needs and I, I think we’re just scratching the surface, really with what we can do. You know, part of our limiter is logistics and resupply and the number of ports we have on station. And so some of the things that limit us are not for lack of interest and let’s say demand. It’s, it’s the supply of my ability to meet all of those. So this is a great- I love that we’re here, right? This is where we wanted to be. We want to make sure we continue to use station to its fullest, and that we are smart with how we transition, and make sure that we keep this energy and enthusiasm up and that we can move it over to a new future platform.
Joseph Zakrzewski
And to help those watching and listening emphasize that point. Just recently, the International Space Station celebrate a major milestone with all ports that are available to station being occupied. So that really kind of hammers home that that point of of the accessibility of station and that everybody wants to be a part of something great. And congratulations on that milestone to the two of you. That is-
Dana Weigel
It’s incredible.
Joseph Zakrzewski
-another great one to celebrate here, especially as ISS 25th is well underway now, transitioning to the future of the International Space Station. What does that mean for low Earth orbit and preparing for that next era of exploration? How does the work being done on the space station today directly support the Artemis campaign, the return to the Moon and then eventually the ambitions of going to Mars and future explorations and using the space station and the knowledge we have acquired over 25 plus years to help inform those campaigns to be successful and as exciting.
Dana Weigel
So, you know, we talked about some of the elements. I won’t touch on life support, again, that’s, I think we’ve talked about why that’s so important. For Mars there are other specific areas that are really important to us that we’re working on on station, and that I think we’ll have to continue to work on with future platforms. Exercise is one of them.
There’s a lot with the human body that we’ve learned in terms of keeping people healthy. There are tons of changes in the human body when we fly in space, and we’re just starting to really understand the cause and effect of those and what we can do to mitigate it. Bone loss is one of the key areas that we tackled early on with Space Station, and the longer you fly, the more we’re really challenged to make sure that we keep the muscular and the skeletal systems healthy. We found the right mix of exercise on board station to help with the bone loss, but it’s too bulky to take to Mars. and so what we’re really trying to do is is now we’re in an era where we’re trying to figure out, how do we take what we’ve learned, and how do we actually make it work for Mars. In fact, we’ve got a new exercise device that’s going up this next spring that we’re going to test, kind of an all in one device gateway is hoping to use it. I think some of our commercial providers are interested in it. But we really got to make sure that it has the same benefits as what we’ve done before in terms of crew health. And so there are a number of key areas that we really still need to tackle, especially for two to three year long missions.
But the other really important piece of it, I think, is in the foundation that we’ve built between commercial, international and, I’d say, NASA and NASA industry capabilities. Finding the right balance, and who can contribute what. Robyn kind of mentioned it before, but it’s really complicated to travel further and further out, and so we’ve got that foundation in work now, but it’s continuing to develop and to make sure that we really have the right full set of capabilities. And we’re going together as we move on to lunar surface for long duration stays and to Mars.
Joseph Zakrzewski
And that was a great example with Gateway and the exercise equipment. How have you seen this progress of being and refer Robyn the progress of the International Space Station. What’s being done today to help impact and shape what these future missions, the Artemis program and campaign to the Moon and Mars and Mars and beyond.
Robyn Gatens
It’s, it’s the technologies, yes, and we’ve touched on life support, exercise, the food system and all of those things. It’s also the expertise, I think, and just the you know that that skills base, and all the knowledge that we’ve developed in- it’s not trivial! 25 years of continuous presence. You know, this program makes it look easy from the outside, but it’s definitely not. And it takes a whole team, and it takes a lot of integrated work, and I think all of that knowledge plays forward, in not just our ongoing work in low Earth orbit, but then our work going out beyond low Earth orbit, where it’s even more critical that we get it right. And so I look at what we built with the station team, and the knowledge not just from inside NASA, but the commercial and international partners as a critical piece of it too, as we go forward.
Joseph Zakrzewski
And it’s a tremendous honor to have both of you here to talk about 25 years of continuous human presence aboard the International Space Station. And my last question for you today and continuing to look forward. And what excites us looking ahead, what excites you about the future of human space flight, the role of NASA’s partnerships and shaping the future of what generations to come will get to experience when they think of space they learn about the space station, and that excitement of curiosity and wanting this willingness to go beyond and explore?
Dana Weigel
I see a future full of infinite possibilities. Space being accessible to more common people? Yes, right now, governments can afford it and in billionaires, but I think the real goal is, is to drive down these transportation, these overall access costs and make it more accessible. I think we have real opportunity to manufacture in space and to discover and to make really significant breakthroughs that that really change our understanding of how we can really leverage space and how we can use it. I think that’s at our fingertips. I think that’s really what our next journey and our step is. And I think low Earth orbit specifically plays a big role in that. It is accessible. And we’ve learned a ton that we’ve got the right foundation to take that leap and continue towards that, that broader vision. So to me, that’s pretty exciting. And our work, I feel like it’s just, it’s still just starting right? We’re still kind of in our infancy in terms of really using and figuring out what we can do in space.
Robyn Gatens
And I’m seeing an explosion of, you know, different kinds of capabilities and platforms and small and large, you know, that’s really, I’m excited to see how that evolves and what that looks like. I’m also, yes, the accessibility, the inspiration piece, is exciting to me that, you know, we make it look easy. We’re up on in space every day there’s astronaut- but you know that the fact that they reach down and touch people here on earth, inspire students to, you know, want to grow up and be scientists and engineers and astronauts. And then you know the- I think the fact that the benefits of what’s being developed in space through the research could actually save lives saved on earth because of the work we’re doing in space. It doesn’t get much more exciting than that.
Joseph Zakrzewski
I love seeing the wonder on people’s faces using that Spot the Station app, when it comes overhead here in Houston, I don’t think there’s not a person that doesn’t look up in awe when they see station pass overhead, and what that means to them personally and the impacts it makes on them. Dana Weigel, Robyn Gatens, again, honored to have you here. Congratulations on this incredible milestone of 25 years of continuous human presence, and we look forward to celebrating even more milestones to come. Thank you for joining us on Houston We Have a Podcast.
Dana Weigel
Thank you so much for having us.
Robyn Gatens
Thank you, appreciate it.
Joseph Zakrzewski
Thanks for sticking around. I hope you learned something new today.
This was our final episode celebrating 25 years of continuous human habitation on the International Space Station. We hope that you’ve enjoyed celebrating this incredible milestone with us.
You can check out the latest from around the agency nasa.gov, and you can learn more about the International Space station nasa.gov/iss.
Our full collection of episodes and all of the other wonderful NASA Podcasts can be found at nasa.gov/podcasts.
On social media we’re on the NASA Johnson Space Center pages of Facebook, X, and Instagram. If you have any questions for us or suggestions for a future episode, email us at nasa-houstonpodcast@mail.nasa.gov.
This interview was recorded on December 3, 2025.
Our producer is Dane Turner. Audio engineers are Will Flato and Daniel Tohill. And our social media is managed by Kelcie Howren. Houston We Have a Podcast was created and is supervised by Gary Jordan. Special thanks to Kara Slaughter and Mary Pfister for helping us plan and set up these interviews. And of course, thanks again to Dana Weigel and Robyn Gatens for making the time to come on the show.
Give us a rating and feedback on whatever platform you’re listening to us on, and tell us what you think of our podcast. We’ll be back next week.
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