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International Space Station and Beyond

Season 1Episode 133Feb 28, 2020

Dr. Gary Kitmacher, communications and education mission manager for the International Space Station program, returns to the podcast to discuss the design, assembly, and evolution of the International Space Station, and how this orbiting laboratory informs future spacecraft designs. HWHAP Episode 133

International Space Station and Beyond

International Space Station and Beyond

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 133, Dr. Gary Kitmacher, communications and education mission manager for the International Space Station program, returns to the podcast to discuss the design, assembly, and evolution of the International Space Station, and how this orbiting laboratory informs future spacecraft designs. This episode was recorded on January 24th, 2020.

In celebration of 20 years of continuous human presence in space, check out this collection of “Houston We Have a Podcast” episodes about the International Space Station.

Houston, we have a podcast

Transcript

Gary Jordan (Host): Houston we have a podcast. Welcome to the official podcast of the NASA Johnson Space Center, Episode 133, “International Space Station and Beyond.” I’m Gary Jordan. I’ll be your host today. If you’re new to the show, we bring in the experts, scientists, engineers, astronauts, historians. We bring them on to go and dive deep into everything human spaceflight. We’re coming up on 20 years of continuous human presence on the International Space Station, an orbiting platform that has provided countless insights into living and working in space. It’s brought us more on understanding the universe, about the effects on gravity, and about the benefits that research can bring to all of humankind. The International Space Station has taught us what humans are truly capable of and inspired so many more to pursue great things. So last episode, we sat down with Dr. Gary Kitmacher, Communications and Education Mission Manager in the International Space Station Program and an author of several books about the space station, among other things. And he took us back in time to discuss some of the early space station concepts and the space stations of history up to the International Space Station. Today we’re continuing our conversation with Gary starting with early concepts for Space Station Freedom. We detail the life of the International Space Station thus far. And we explore what we can expect for the future of space stations. This episode was inspired in part by Comic Reader on Twitter, who wanted to know more about a specific part of International Space Station history. We touch on that during today’s episode. And thanks for submitting the idea, Comic Reader. So here we go. The International Space Station and Beyond with Dr. Gary Kitmacher. Enjoy.

[ Music ]

Host: Gary, welcome back to the podcast to continue our conversation about space stations.

Gary Kitmacher: Thanks for having me.

Host: So, we left off kind of this overlap period with [Name of the Russian Space Station] Mir. We were talking about the end of Mir and the beginning of space station. I wanted to start with space station. But just from talking a little bit just beforehand, it really — I think starting in the late ’90s wouldn’t be appropriate. We really have to start kind of even back in the ’80s to start talking about the concept and the early ideas for what would be the International Space Station.

Gary Kitmacher: Well, really the shuttle and the space station were both thought of at the same time. And they were intended to go hand in hand. The shuttle was the means to build and support and logistically supply the space station. And the space station was necessarily going to have to look like something that the shuttle could build. And the first ideas got started even before the program was begun in the late ’70s and early ’80s. Here at the Johnson Space Center, we focused on something called the Space Operations Center. And it was going to be a base for doing all kinds of activities in low-Earth orbit. At Marshall Space Center in Alabama, they were focused more on utilization and science and payloads. And they had been working closely with the Europeans on the Spacelab. And so, a lot of their ideas were based on a takeoff from the Spacelab that was being carried up in the shuttle. We wanted to get the president to actually announce the beginning of the program. And once James Beggs came in as the NASA Administrator, about the time that Ronald Reagan became president, that was really the focus was getting Reagan to announce the program. And it didn’t happen very quickly. We kept expecting it to be announced. But it didn’t actually occur until the State of the Union Address 1984. And Ronald Reagan announced that we would build a space station. We would do it within a decade. So, it would be up in orbiting by the early 1990s. And one of the things that he announced and that he told James Beggs right from the start was we wanted to do this in cooperation and collaboration with our friendly partners. And so Beggs went out around the world looking for a partnership to establish with the Japanese, the Europeans, the Canadians, anybody who we had worked with previously on space activities. And so that was the beginning of the international aspect of the space station.

Host: OK. So, all of these different countries maybe not necessarily had fully formed space agencies, but they had, maybe agencies, government agencies, dedicated to space activities in some way?

Gary Kitmacher: They were a variety. Some of the agencies had worked with us previously. And some of them had worked as agencies. And some of them had specific industries within their country. So, for instance, in Canada, well, there was a Canadian Space Agency. There was a specific company that was focused on the development of the robotic arm used on the space shuttle. And they wanted to build a next-generation arm that would be used on the space station. In the case of the Europeans, although there’s — actually been several European Space Agencies that had evolved over the years, there were also specific companies in Germany and Italy that had been responsible for designing and building modules like the Spacelab. And they wanted to build modules for the International Space Station. Some of these actually would go through an evolution. For instance, the Spacehab company, which was a commercial company, one of the early NASA forays into commercialization in the mid to late 1980s, their module was actually built by the Italians. And so, they would become the basis for modules that would be built for the space station.

Host: Was that the primary reason for collaboration was for — the pitch was, “Hey, we want to go and build this modular space station. And we want you to build modules.” Was that the pitch?

Gary Kitmacher: It was part of the reason. Really, the international aspect grew out of the fact that because we were launching it on the space shuttle, they had to be modular. The shuttle was only capable of launching a specific mass in a specific size. We knew that they had to be within about 60 feet long, 15 feet in diameter. And depending on the altitude that we would place it in orbit between about 30 and 50,000 pounds for each launch. And so, we were very constrained by the payload capacity of the shuttle. But it also led to kind of a natural mechanism to decide that this country’s participation would be limited to these pieces that would go up in one segment or in multiple segments, in the case the Japanese.

Host: OK. Yeah — we were thinking modular. And when it comes to the logic of how this was going to happen, and I guess what we were pitching, we were thinking about — I know in space-assembly was one of those elements versus, I guess, building a larger rocket. Because you already mentioned the space shuttle as one of the drivers for what would be the components of the International Space Station. So, assembly was going to be a big part of it, which meant spacewalks, which meant robotics to really make this thing come together.

Gary Kitmacher: There was discussion right along about building a large booster based on the shuttle, something called the Shuttle-C, although there was never really an initiative to get going with that. We were already launching shuttles at the rate of about one a month by 1984, 1985. And so, we anticipated that the shuttle would be a capable workhorse. We were already doing some [Extravehicular Activity] EVAs. When we started looking at what it would take to build and assemble a space station, we came up what some people called the wall of EVA because it was now going to take not just tens or dozens of hours. It was going to take hundreds and thousands of hours of EVA in order to assemble the station. And that was one of the areas that caused us to go back and do a lot of relooking, scrubbing, trying to pare down the amount of activity that would be required to assemble the station.

Host: Hmm. So when we were thinking about what it would take, tell me about, you know, in terms of resources, in terms of how we thought this would all come together, I think some of the early designs was Space Station Freedom, and then how we went from that concept and that idea for how to build this space station to what was eventually the International Space Station.

Gary Kitmacher: We started looking at the modules. That was an area that I was particularly focused on. I was part of what was called the Man-Systems Division. And so here at the Johnson Space Center in Building 15, we built the first mockup of a module of the space station out of foam core, out of basically cardboard and Styrofoam. It was based very much on the Spacelab modules racks, similar to what we’re inside the Spacelab module. And we looked at, well, how many of these modules would we need? How large could the modules be? And then other people started looking at how would you connect the modules together to the power supply, to radiators, to the other systems that would be required to support a space station? And out of all of that study came the concept of the common module, where all of the modules looked essentially the same, and the power tower. It was a long truss. And then up at one end of a truss was a T-shaped segment that attached all of the solar power cells. And at the opposite end of the long truss were a series of about five of these common modules attached together. Some of these modules would be habitation modules. Some of them would be laboratory modules. So that was our initial design of what would later become Space Station Freedom. It wasn’t named for a couple of years at this point. The common module we thought was a good idea because we likened it to building an airliner, where airliners are turned out. If you look at the Boeing airliners in particular, the fuselages of most of the smaller airliners are the same. And they just keep building segments of fuselage. And they cut them off depending on the kind of airliner. A 727 is one length. The 737 is a different length. And then they put a nose and a tail on it. And we were looking at modules that would be built in the same way. So, you would build a module to a certain length, put the ends on either side and hatches around certain pieces. From that, we evolved a little bit to the idea that modules would be specialized. Some of the modules would be used to connect other modules. This was because if we had too many hatches and too many docking attachments, which the first common modules had a series of four docking hatches and docking segments around the periphery, around the circumference, and then one on either end, then the module was too heavy to put much inside during launch. And also, the hatches used up an awful lot of the interior volume. And so, you really couldn’t put as much on the inside. So, we very quickly evolved to a long module, which became the U.S. Lab in the U.S. Hab, and nodes, which were short modules, but which contained all of docking interfaces. And, in fact, that’s still the design that we use today, where we have three nodes, and we have the U.S. lab, which is the long module. Interestingly enough, the European module, they decided, they could make even shorter by putting some of the systems on the end cones of the module. So, the European Columbus Module started out like the U.S. modules but grew shorter. But the Japanese module, on the other hand, stayed exactly the same length as it was originally. And, in fact, it’s now the longest module of the space station. But they were all supposed to be that long originally.

Host: Oh, interesting. So, what was the driver for the size of the International Space Station and the modules that would be “needed” for this orbital laboratory?

Gary Kitmacher: We were initially looking at a crew size of at least eight people and perhaps growing to as many as 12 people. There were some discussions early on in the late 1970s, early ’80s that perhaps a size of only four people would be adequate. And then there were other studies that said, well, with four people, you really can’t do as much utilization, as much science. And so, you need a larger crew. And so, there was some discussion and give and take on that. And we wound up going for a crew size of eight. And that necessitated the two large modules, the Hab and the Lab, and a series of smaller nodes that would contain some of the supporting systems. One of the areas that I got involved in early on in around ’86, ’87 was looking at what were all of the systems and how would they best be packaged. And so, we went through all of the different kinds of hardware that you might put on a space station. We had to design what kinds of support systems we were going to be supplying. For instance, in the case of food, we thought a frozen and refrigerated food system would be the best. It was the most palatable. We had a lot of our food specialists at the time contributing. And that necessitated refrigerators and freezers. When we got into some of the budget battles, as well as electricity battles and how much power they used, other people came in and said, “No. Refrigerators and freezers are not good. They use a lot of power. It’s a lot more expensive to build those. And so, let’s go to an ambient temperature food support system.” Something like what became [Meal, Ready-to-Eat] MREs in the military, you know, actually started with a lot of the study work that we were doing here at the Johnson Space Center. We looked at things like irradiated food, which at that time in the 1980s had not been certified, not been approved by the U.S. Federal Food and Drug Administration. But because of some of the pioneering work that we were doing here, that was later adopted. And so now you see a lot of ambient temperature food on your supermarket shelves as a direct result.

Host: All right. As a direct result of the needs driven by —

Gary Kitmacher: By the space station going to an ambient food system.

Host: By the space station. Wow. So, on this topic of systems, tell me about the logic of designing the space station as we see it now, with the truss segment, with solar arrays, with batteries, with the habitable modules the way that we are discussing now.

Gary Kitmacher: Well, as we started out the different systems were going to be developed and built by different what we called work packages, different contractors, and different NASA centers managing them. And so, the power system was originally going to be a product of what is now the Glenn Research Center up in Ohio. The modules became a product of the Marshall Space Center in Alabama, although with an important role for Johnson in managing those modules. A lot of the supporting systems, the guidance navigation control computers were being developed here at the Johnson Space Center because of our role in managing the spaceflight program. We looked at how do you package those systems? And how do you tie them together? On the inside of the modules, we looked at the Spacelab racks. And we went to a somewhat simpler and more elegant design, a common rack that could be put into the floor, the ceiling, and the walls of the space station. They were basically refrigerator sized up to a mass of about 1000 pounds. And they were sized in such a way that if we ever got punctured by a micrometeorite or a piece of orbital debris and we had to plug a hole, the rack could be pulled away from the wall very quickly to gain access to the pressure shell. Keep in mind, we were looking at how do we maintain these modules over a very long period of time, decades. And so, it was very important that it be modular in approach. And so, a lot of the keywords that we wrote into the documentation, both for our requirements and into the contracts, were associated with modularity and upgradability. And so that we would be able to recover from any kind of problems and issues in orbit. The other systems, such as the solar power cells and the radiators and eventually even the computers, we looked at how can you put those things on the outside of the station? How can you attach them originally on the Space Operations Center? And it was a somewhat simpler design approach. But they were not quite as easy to put into place during assembly. And if you ever had to change them out, it would be difficult to take them apart.

Host: Thinking about EVA. Thinking about a spacewalk.

Gary Kitmacher: And so, looking at EVA and robotics and how you assemble the pieces, we designed around this idea of the central truss and attaching these as different modular entities that can be attached to the truss. The truss itself went through quite an evolution. Originally, we were going to build the truss out of what we called sticks and balls, kind of a Lego set in orbit, lots of little pieces. And because of some of the concerns associated with all the EVA hours, we went to a modular truss approach, where the trusses were pre-integrated. We would fill the truss up with as much of the equipment as we could. It would be pre-assembled. And then we would launch them into fairly large segments on the shuttle. And so, from about 1985 through about 1989 or so, those aspects of the space station, what became Space Station Freedom, grew pretty definitive. Now, keep in mind, we did a lot of the early work at the different NASA centers, looking at the design approach to use and specifying the requirements. Ultimately, what was built was an outgrowth of the contract competition. So, for instance, a number of us from Johnson Space Center, because of our integral work on the modules, actually went off to work Package 1 into the Marshall Space Center. I was one of those people who worked out of Marshall for about a year during the source board. And ultimately what came back from the different bidders was what was built for the space station, still looks pretty much like the space station today. Now some of the things, the contractors and NASA did not necessarily get right. And, for instance, one of these things was the size of the modules. NASA specified in the requirements that the contractors were to bid to that the modules were to take up the full capacity of the space shuttle payload bay. And so, one of the bidders on the work batch one contract — the two bidders, by the way, were Boeing and Martin Marietta — and so one of the bidders said that they could put a 60 or 65-foot-long module and they could launch it fully outfitted, fully loaded with gear. And then the other contractor said, “Well, a fully outfitted module would never be able to be lifted by the shuttle into the required orbit. And, therefore, we would have to either shorten the modules or we would have to launch the modules up largely empty and then send the interior contents up later in logistics modules.” And, in fact, because I had been involved with shuttle payload integration, one of my jobs during the source board was to write a white paper comparing the two approaches and who was right. And my statement was neither one is right because NASA specified the wrong requirements, so.

Host: So, what was the need then? What did we end up choosing?

Gary Kitmacher: What we ultimately ended up doing was shortening most of the modules and launching them up partially outfitted, so as much of the equipment that could be integrally integrated inside as we could, given the mass limitations. So, the modules wound up not being — they were probably never going to be 60-feet long. But the original modules of the space station were supposed to be about 48-feet long. And, in fact, now the longest U.S. module, the U.S. Lab, is only, I believe, about 30-feet long.

Host: OK.

Gary Kitmacher: And so, we did have to constrain the length because of the mass limitations.

Host: So, you’re defining these requirements for the contractor and going — having this back and forth with the contractors for some of the U.S. segments. Now what about the international side? What —

Gary Kitmacher: Well, the internationals were going through a similar kind of approach. And in some cases, they were a little bit further behind us. So, for instance, although we were working right from the very outset with the Japanese and with the Canadians and with the Europeans, they were learning a lot from how we were looking at the situation. For instance, as I mentioned earlier, we were building the mockups of the modules here at Johnson. And the work was being done within our group that was not in engineering. It was in the Space and Life Sciences organization called Man-Systems, Man “dash” Systems. These days, it probably would not be politically correct to call it that.

Host: That’s right. ‘Human-rated,’ that’s what we use now.

Gary Kitmacher: But we were not so forward thinking at that time. It was interesting because the Japanese came. I remember, Mr. Shiraki, who was their program manager, came very early on, probably in ’86, or ’87. And we toured him through the mockups and showed him how we were approaching the design. And they thought it was very interesting that we would have such a focus on the human aspect of the space station. That was something, he said, the Japanese really did not know how to do. The next year, they said, “We’re coming to Houston with our Man-Systems Advisory Group.” And so, they learned very quickly from us how to establish exactly what we already had in place here in Houston. And pretty soon they were using the same approach. Some of the aspects were political. For instance, the Japanese, just as we have to fight in Congress for monetary support to build all of these things, had to do the same thing with their government. And they went through. And they said, you know, “We want to build this large laboratory, and along with the laboratory, a logistics module and an external platform.” There was a lot of concern over robotics. And so, the Japanese said, “Well, the Canadians are building the main robotic arm for the station. But we’ll build a robotic arm, too.” So, a lot of these things wound up on the Japanese module. When we ran into problems such as the mass limitations of the modules, the Japanese, because they had sold it to their government that they were going to have a big laboratory, stuck with their big laboratory, as compared with the U.S., where we reduced the size. And that’s how the Japanese wound up with the largest lab on the station.

Host: All right. Now tell me about construction. You already alluded a little bit earlier in our discussion about this wall of EVA since with some of the early construction. Tell me about how that started and worked.

Gary Kitmacher: We had a series of EVAs going on in the shuttle program through the early 1980s. We had rescued some satellites that had been put into errant orbits. They weren’t the right orbit, or the satellite did not start working the way it was supposed to. And so, NASA and its shuttle were sent up to rescue the satellites. Sometimes activities went as planned. Other times, they didn’t. We sent up some tests of space station hardware. For instance, we built a segment of truss off of the space shuttle. And some of the problems that we focused on during that test said it was going to perhaps be more difficult than we had originally assumed. We had a study conducted by Astronaut Bill Fisher and Charlie Price of the Engineering Directorate. So, it was called the Fisher-Price Study. And they said, “Oh, this EVA situation could be pretty difficult with thousands of hours required to build the station. And especially if something doesn’t go right, if we can’t get some certain things put in place, then it could affect the entire assembly sequence.” So that was what got us looking at the idea of the pre-integrated truss. Some of the people in the engineering directorate, who are still here today, actually patented that idea of the pre-integrated truss. And so that changed our direction a little bit, although ultimately the number of EVAs that have been required on the International Space Station has been far more than any prior program, still in the, I believe thousands of hours now. I think we’re up into the 200 EVAs or thereabouts today. And so, it’s required quite a number of EVAs and a lot of activity, just as was foretold back in the 1980s.

Host: Yeah, for sure. I think, yeah, we’re way up there, thousands. Yeah. I think 1,500 hours, I think, was the last statistic for the last spacewalk that we did. Because we’re beyond construction now. This is construction. This is maintenance, you know. We’re talking about switching out the batteries because the batteries don’t have —

Gary Kitmacher: Changing out batteries and other components that have been up there for decades now.

Host: That’s exactly right. So, tell me about some of the early years of space station with some of the smaller segments, you know. We’re talking STS-88 and Expedition 1, life there and how that technology has improved over time, going from the small station and then eventually building on with this assembly sequence. What changed, what upgraded, and how what we learned improved our understanding of how to operate this thing?

Gary Kitmacher: Well, I’ll bring in NASA Mir here because NASA Mir was a program that we conducted between about 1995 and 1998. So, it was leading up to the first assembly missions of the ISS. And especially for those of us who were working on the inside of the space station, it was very important. We learned what kinds of equipment we would need. We learned how to work with the Russians. We learned how to establish appropriate documentation and integration processes. And so, a lot of that was done early on. In my own case, I had been the stowage manager on the shuttle during the mid-’80s and also was responsible for integrating a lot of the payloads on the shuttle. And so, when I was put in charge of one of the last modules on Mir, I said, “Well, we can streamline the process for integrating payloads if we had common interfaces.” And so, I designed the [Crew Transfer Bag] CTBs, the soft stowage bags that, quite honestly, was something no one else had ever thought of previously. And so, when the first mission was getting ready to dock with the Mir STS-71 in 1995, they discovered just a few weeks before the flight, we have no way to carry things over between the shuttle and the Mir. How can we do this? And I said, “Well, I have these CTBs in manufacture.” We were actually building them here onsite at JSC. They were in orbit within a matter of really weeks.

Host: Wow.

Gary Kitmacher: And so, we were fortunate in having that available. Computers, when we started the design of computers for the space station in the 1980s, there was no such thing as a laptop computer. The first small Apples, Apple computers, were coming out probably around ’87 or thereabouts. I remember when I went off to the source board. Because I was the scribe — I was the person writing a lot of these documents — they repackaged one of these Apple computers. It wasn’t by any means a portable. We called it a luggable. But we were looking at large refrigerator-sized racks full of computer equipment in the 1980s. By the time of Mir, when our first astronaut went up to the Mir, he said he really could have used some kind of a computer system to read documents on, read training manuals, because otherwise we had no way of sending up lots of different manuals. Even during his off hours, he said, “Boy, I could use something just to watch a movie on.” And so, I was given the job to develop the first portable computer to be used as a training aid and also to be able to be used in off-duty hours. I remember we recorded on to small eight-millimeter cassettes The Apollo 13 movie among others and sent those up in 1995. And, of course, now, today, all of the computers on the space station are basically portable computers. The [Portable Computer System] PCS system of the space station really is the heart of the computer system that drives everything. We have no rack-sized computer equipment anymore.

Host: Thankfully.

Gary Kitmacher: So, we’ve gotten away from that. But keep in mind in 1985, when we got started, it just didn’t exist yet.

Host: Yeah.

Gary Kitmacher: Hadn’t been invented. A lot of the other equipment we were testing out first on NASA Mir. And then we were observing some of the equipment that the Russians were using, their waste management system, their treadmill. We got into some arguments here at the Johnson Space Center about how critical some hardware was. So, for instance, the ISS program at the time did not feel that exercise equipment was critical.

Host: Oh.

Gary Kitmacher: –And the exercise equipment we were developing was not put through a lot of testing when we first launched it into orbit. And so, the first crew started using it around the year 2000. It immediately collapsed. It had not been tested adequately. And so, we had to go back and redesign it and rebuild it to be much stronger. And we discovered that if the crew cannot exercise, this is a critical failure. And you start thinking about bringing the crew home within a matter of a month or less. And so, it turns out it is really critical hardware. And it is something that you need to give serious thought to. And it has to be adequately tested before it goes into orbit. So, we were learning a lot of these lessons as we were going. We started out with the Mir flights that allowed us to test a lot of this equipment, including some of the scientific payloads. We sent up the first microgravity glove boxes, prototypes for what would later fly on the ISS. We sent up other kinds of devices that were intended to limit the number of vibrations between the payload and the vibrations of the structure of the space station. So, we tested those out. And then we would launch up more significant systems for the ISS. We looked at the design of the Russian waste management system and also how they use the different systems for recycling air and water. And we were already involved in developing some of that for the ISS. But the Russian approach was often very simple, almost elegant in its simplicity. And so, we adopted some of those approaches and made our systems a little bit simpler, too. And I think in the long run that has worked out better, in terms of being able to maintain and support the system in orbit.

Host: Now how about data and communications? I know that was a big one over time and the improvements there.

Gary Kitmacher: Well, a lot of things really did improve significantly. Mir showed us a lot of the problems of a space station or a lot of the potential problems. A lot of our experience on Mir was pretty negative because, first of all, Mir was very old when the U.S. started flying the shuttle up there. It was only intended to last about five years. And by the time the first shuttle visited, it had been up there for nine years.

Host: Oh, wow.

Gary Kitmacher: And by the end of the program, we were going on about 15 years. Mir had very limited communications. Because of the collapse of the Soviet government, they really no longer had the [Tracking Data Relay Satellite] TDRS kind of a satellite that would allow them to maintain continuous communications.

Host: Geosynchronous ones.

Gary Kitmacher: So, a geosynchronous communication satellite. And, therefore, astronauts and cosmonauts could only communicate when they were within range of a few ground stations mainly across the old Soviet Empire. And so, they were fairly limited in how much communications could go back and forth. In the meantime, we had computer systems that were growing more sophisticated. For instance, we had Wi-Fi in the first laptop computers that we put on the Mir. But the Russians were somewhat hesitant to use something like that because of the potential interference of electromagnetic signals and so on. And so, we were learning a lot about how to do that. And they were learning quite a bit about how that could affect things. By the time the International Space Station comes along just a few years later, we have learned a lot of those lessons. We had grown somewhat more sophisticated. Our systems were new. And they were working well. We were very dependent on computers on the ISS, whereas Mir had evolved from being a pre-Computer Age kind of a station in the ’70s and early ’80s. Prior to Mir, they were more dependent on computers. But by Time of ISS in 1988, we are very dependent on computers. In fact, the first crew that reaches the space station says they can’t turn the lights on. They can’t turn the lights on because you do it through the computer. And they can’t find the computer because the lights are off. And so that were some of the lessons that that we were learning at that time. So, the computers were growing far more sophisticated and capable. Communications was almost continuous because we did have the TDRS System in orbit.

Host: Now what did we learn about life on the station? We were jumping right into some of these long expeditions and what it takes to operate over these periods of time.

Gary Kitmacher: Again, we had learned on the Mir that a lot of the crew time is spent just maintaining the station, and fortunately, because the ISS was somewhat simpler and there wasn’t as much stuff on the inside, it was a little bit easier to access different areas. So, it didn’t take quite as much time to maintain the systems, and when I’m talking about maintaining, just wiping down the interior with various kind of biological materials to control the growth of any kind of hazardous contaminants. That was something that we had faced on Mir. And on ISS fortunately we didn’t have to deal with that as much. But we still had to spend at least about a day a week by the crew cleaning and maintaining a lot of the systems. We learned quite a bit about the health of the astronauts and how the health of the astronaut’s interface with the environmental control and life support system. So, for instance, we knew for a long time that the astronauts were losing minerals from their bones. Their bones were growing weaker, like osteoporosis in the case of the elderly. It was the same kind of thing in orbit, as well as the muscle mass of the astronauts was decreasing. And so, these were things that we needed various kinds of countermeasures, exercise countermeasures. What we did not appreciate was a lot of these minerals that were coming out of the astronauts was coming out in the urine. And therefore, in our waste management system, which was processing the urine, we formed what euphemistically was called urine brickle. And it was clogging up the systems on the environmental control recycling equipment. And so, we were learning quite a bit and had to go back and redesign some of the components so that it was less susceptible to some of these kinds of problems.

Host: Wow. Now you talked about a lot of crew time, especially on Mir, was dedicated to just maintaining, you know, fixing this or scrubbing down that. But I think the goal of the International Space Station was eventually to move towards maximizing utilization time or the time you dedicate to science.

Gary Kitmacher: We had looked at how best to use the space station right along from the very beginning. A lot of the top-level NASA management felt that it was all about science. It was all about building a user community that was going to be supportive of human spaceflight. And, therefore, we were trying to develop experiments, first on shuttle, later for Spacelab and then Mir that could be developed into more sophisticated systems for use on the ISS. One of the problems early on, on the ISS was that would be with the small number of crew members initially, just three and then eventually growing to four and not getting to eight until later years, after about 10 years or so, we really did not have as much crew time as we would have liked. If you take a look at the crewmen’s day and how much time they have to spend maintaining themselves, whether for exercise or cleanliness and so on, but then how much time they actually had available for doing scientific work, it was pretty constrained. And so, we were learning quite a bit about how to either automate some of the systems, how to operate a lot of the systems from the ground. And so, this has been developed really to the point now where the astronauts, although they do have to do some on-orbit actual maintenance of the station, most of the system-level activities, operating the systems, is done from the ground. And so, the astronauts do not have to focus on that so much. And they do have more time to focus on scientific experiments.

Host: Yeah. And they’re every kind that you can imagine. They’re Earth observation. They’re biological. They’re systems. They’re really everything. I want to kind of zoom in on International Space Station history to the Columbia accident. What happened there, in terms of the assembly? And then what we had to rethink and redo and then get back up on our feet to eventually finish construction of the space station?

Gary Kitmacher:Well, of course, the initial assembly mission occurred in 1988. And so, from ’88 until 2003, when the Columbia accident occurred, we were able to do a fair amount of assembly work, although we were somewhat limited because the Russians were not moving along quite as quickly as we had hoped with the service module. The Russians only have a limited number of people that they apply on any of their modules. And so, they had to first do the [acronym for Russian words for functional cargo block, refers to Zarya module], FGB. And it wasn’t until the FGB was in orbit that they were able to move on to the service module and get it ready to fly. That was finally ready. The first crew went up. The first long-duration crew went up in, I think, 2000. And so, they took their place in orbit. And so, then we had about another almost three years to work in space before the Columbia accident occurred. At the time the Columbia accident occurred, we really were not in the best of situation in terms of having all of the electrical power and radiator systems in place. We had just started building out the truss. In a way, we were fortunate in that we did have a fairly balanced station, where equal amounts of truss had been placed on both sides. And, therefore it was somewhat easier to control and maintain in orbit. But, of course, we had been so focused on building and assembling the station using the shuttle that when the shuttle stopped flying after Columbia, we really were not able to do any more assembly work. And so that stopped everything for about two years or so until the Return to Flight.

Host: And the Return to Flight, did that kick off a rapid set of assembly missions?

Gary Kitmacher: One of the problems we had run into prior to Columbia was we were bringing the different elements of the station down to Kennedy and preparing them to fly. But oftentimes we would have one element there and the next element they had to connect was not really there to do any kind of testing on. So, we frequently had to do simulators in place of the actual test articles. When the Columbia accident happened, in a way it worked out fortunate in that all of the equipment began to coalesce at Kennedy Space Center. And so, we could put a lot more of it together, test it out more thoroughly prior to launch, and that way — when we returned the shuttle to flight, the assembly missions could go off much more rapidly, almost at the pace of about one a month or so, one every month and a half or so. And so, we were able to move along pretty quickly.

Host: OK. Now I want to talk about operations for a second because I think you’ve mentioned it a few times that — you mentioned the space station was designed to be a bit simpler. So, the crew didn’t have to do much. But really this is different from even shuttle, where it was the crew that was flying the shuttle. The space station is almost flown from the ground, operated from the ground. You have 24-7 operations. And then on top of that you have international operations. So, tell me how that structure came about?

Gary Kitmacher: Well, of course, computers and computer networking has evolved quite a bit over the years, over the course of the last 20 years. And so, this has allowed the people on the ground to have almost as much, and sometimes even more, insight into situation on the station than the crew has. It also means that you can have specialists all over the world specializing in their own systems. They don’t necessarily have to come here to Houston, or in the case of payloads, the Marshall Center in Alabama. They can oftentimes stay in their own local control centers and operate their systems from Oberpfaffenhofen, Germany, or from Tsukuba in Japan or from wherever the location is. So that means a lot more of the people that maintain and operate the station can do it remotely, not only remote from the station, but remote parts of the Earth.

Host:What did it take to switch to Because for when it comes to Mission Control, before the International Space Station, a lot of what we know is mission control was staffed for a mission. And you would train. And you would do simulations. And you would do that. But now we’re talking about continuous staffing, making sure that someone’s in the room at all times, because you already mentioned it, almost 20 years of continuous human presence now, someone’s got to be monitoring those guys.

Gary Kitmacher: On the one hand, we have people on the ground continuously monitoring and continuously operating the systems. And, on the other hand, through the use of intelligent systems and a lot more understanding of how the systems operate, we can have a relatively small number of people operating the station. And so, the number of people we have during a holiday or on a weekend is not nearly what we would have during a normal workday, whether in Houston or in other parts of the world. Now, keep in mind, while this is somewhat simplified and made somewhat less expensive, the operation of the station today, when we start talking about, whether it’s a Moon base where’s communications laps of several seconds, or a Mars mission where the communications lapse can be more on the order of 45 minutes, we have to start rethinking, is this going to be the way in which we can operate? How do we operate the systems when you can’t do it real time?

Host: Yeah. Definitely a huge consideration. And I want to kind of take that as a jumping-off point from we’ve had this long conversation about the International Space Station and what — I’m trying to establish is just what went into this thing, what it takes to put this thing together, to construct it, to make it permanently habitable for 20 years. Thinking about that, thinking about those lessons, what are we taking now and putting towards the Gateway, which is not meant to be continuously inhabited? You know, we talked about improvements of technology and just lessons that we’ve learned throughout all of these years going towards a Moon-orbiting platform.

Gary Kitmacher: Well, right from the very start, we envisioned the space station in low-Earth orbit as being a prototype for the kind of vehicle that you would use for, not so much lunar as much as planetary missions, a vehicle that would take off for many months or even years to carry astronauts to distant planets. Early on, we were thinking about the planets Venus and Mars. Now our main focus is particularly Mars. And so, depending on the mission that we would be going on, it could be a mission of anywhere from 18 months, probably at the minimum, to several years, three or four years, maybe even longer than that. A Gateway is a particular — kind of space station that would be used to support the lunar missions. And so, because of the way in which the Orion is developed, it would need a base in orbit around the Moon that it would be able to dock to and stay there while astronauts are down on the lunar surface and then carry the astronauts back from the gateway back to the Earth. And so right from the outset, we were looking at developing the kinds of systems that would be required for taking care of people for very long durations. And when I say taking care of people, they not only have to be operable. They really have to be able to operate with minimal maintenance, with minimal kinds of systems difficulties over very long periods. And I think we’ve been doing that. We’ve been doing that with not only the environmental control system, the exercise systems that are fairly critical in keeping the people healthy and active, but with computer systems, communication systems. All of the different systems that we need to support a space station, we’re learning how to depend upon them. And through some of the problems we have faced, we’re learning how to redesign and develop them in such way that they are dependable for future years.

Host: Now what’s interesting is we’re talking about the International Space Station being a lesson for traveling further out into the solar system, which I think was one of its many purposes from the get-go was to learn how to do that, how to design systems, how to live and work in space for a long period of time, but I know we still want low-Earth orbit as a place to continue to practice, to continue to develop technologies, to continue to train crews. This is a place we need. And looking further further into the future, the International Space Station is not meant to be there forever. So, the transition is to a more commercial economy. Tell me about the transition on the International Space Station, what we’re learning and what we’re doing now to eventually transition to this low-Earth orbit economy.

Gary Kitmacher: Well, of course, the space station, because of its location and low-Earth orbit, has a number of attributes that are useful. One of them is microgravity or zero gravity so that we can look at different kinds of physical processes in orbit in this very low gravity field environment as compared with one gravity here on the Earth. Another aspect is the observational aspect. And so, we have scientific windows. We have the Cupola windows of the station. And the astronauts spend a fair amount of time looking at the Earth and particularly looking at things which really haven’t been planned in advance. So, if there are fires in Australia or volcanic eruptions, they’re right there looking at them, taking pictures, making observations. And, of course, these were all things that were foreseen from the outset. And we’ve seen that they have been useful for different kinds of companies. Some of them looking at very basic research. Others are looking — at much more specific kinds of products. In 2005, the ISS was designated a National Laboratory. And in 2011 they brought in an independent organization called [Center for the Advancement of Science in Space] CASIS, to operate the national lab. And they go out around the country and try to tell people about the availability and the possibilities of using the International Space Station. Other companies have been coming along. Axiom Space, Mr. Bigelow with his inflatable modules, and so others are coming along. And depending on whether there is a commercial opportunity or not, whether they can make access to space reasonably inexpensive and they have an orbiting platform, then in the future, the opportunity will be there for commercial operations in a space station. In the meantime, the ISS is being used in this way already, not only by the U.S., the Russians, of course, have famously been bringing various tourists up to the space station for visits. And in the future, we think that we’ll have more opportunity for various kinds of commercial activities on the station.

Host:Do you think– Yeah. What you’re talking about now, I mean, we talked about International Space Station informing lunar exploration, informing Mars exploration, everything it takes there, being in this place where there’s commercial viability for operating in space. How big of a role do you think the International Space Station played in that? And do you think we can even be in this place without the International Space Station?

Gary Kitmacher: I think the International Space Station has been critical in learning how to design, build, and operate different kinds of hardware and systems, learning how to work together with international partners. Keep in mind, we have not only the Russians, but 16 or 17 different countries. The number has varied over the years. And we’ve learned how to work with them. I know early on, I worked very closely with the Russians. They did not really have a good understanding of how the U.S. went about putting things in orbit on the shuttle or on the station. And we developed joint integration processes, joint documentation. I know I was talking with my Russian counterpart from the Mir years just a few weeks ago. And he says, “Well, the work that we had laid in 1994, 1993 is still the basis for how the Russians work today.” So, they learned a great deal about how the more advanced world, I guess, does payloads and science and experiments in orbit. And at the same time, we’ve learned how a lot of their hardware is built and designed. I know I was involved in the design of Moon bases and Mars vehicles back during the first President Bush’s space exploration initiative. And a lot of the hardware that we have actually built for the space station today, whether it’s the most basic hardware, the modules, the nodes, the racks, the Cupola, or down to the more detailed aspects, the CTBs, the stowage bags, the computer systems, the communication systems, a lot of these will actually become the components of future Moon bases and Mars spacecraft, just as today we’re looking at using a lot of these pieces on the gateway in orbit around the Moon.

Host: Wow. What are you looking forward to the most then for the future? You have this gigantic history in your brain of everything that’s happened over the years to get to this point. What are you looking forward to the most?

Gary Kitmacher: Well, I’ve been lucky enough to participate in a lot of these programs and even have a hand in the design and development of a lot of the hardware. And so, every time I see, whether it’s the CTBs or the Cupola or the [Crew on-Orbit Support System], Coss computer system, these were all things that I had a direct hand in. And I’m looking forward to seeing some of those same systems on the first Moon base or on the first Mars spacecraft. Right now, I’m looking at them in orbit around the Earth. You know, Cupola, of course, is famous as the astronauts’ favorite place in space to observe the Earth. That grew out of a lot of infighting, in terms of what the astronauts needed, what we had to be able to provide for the astronauts. And we’re lucky that we have it in orbit today. But now I’m looking at putting a system just like that on the Moon base and on Mars.

Host: Leaving your mark on human space exploration forever. That’s amazing. Gary, thank you so much for going through this history. This has been a fascinating two discussions really through the concept of space stations, through what we’ve learned and what it’s taken to put together the International Space Station and laying the groundwork for what’s to come. I really appreciate your time.

Gary Kitmacher: Thanks for having me. I was glad that I was able to offer something of interest.

Host: I loved it. Thank you.

[ Music ]

Host: Hey, thanks for sticking around. I hope you listened to two of these parts with our conversation with Dr. Gary Kitmacher. This is Episode 133. If you haven’t, go back and listen to Episode 132. It’s a fascinating conversation on everything that happened before the International Space Station. I hope you tune in. You can find it at NASA.gov/podcasts along with the other NASA podcasts that we have throughout the many Space Centers here at NASA. If you want to learn more about the International Space Station, I’d be surprised. But there is more that you can investigate at NASA.gov/ISS. We got social media places where you can go, Facebook, Twitter, and Instagram. Just search the International Space Station. We got account on all three of those. Use the hashtag #askNASA on your favorite platform to submit an idea for the show. And make sure to mention it’s for Houston, We Have a Podcast. For our students out there, I have a quick plug for you. Research in the microgravity environment of the International Space Station is still as important as ever. And to celebrate 20 years of continuous human presence, both living and working in space, our STEM on Station team here at the Johnson Space Center will fund five student-designed payloads to fly to and return from the space station as part of the Student Payload Opportunity with Citizen Science, or SPOCS, S-P-O-C-S. For more information and to submit proposals, just make sure to check out NASA.gov/STEMonstation/SPOCS, S-P-O-C-S. Mark it on your calendars that the submissions are due by 5 p.m. Eastern on March 27, 2020. This episode was recorded on January 24th, 2020. Thanks to Alex Perryman, Pat Ryan, Norah Moran, Belinda Pulido, and Kelly Humphries. Thanks again to Dr. Kitmacher for coming on the show. Give us a rating and feedback on whatever platform you’re listening to us on and tell us what you think about the show. We’ll be back next week.