May 30, 2003 

An Interview* with Constance Adams
Architect for the TransHab Inflatable Space Station Module
* via email


Constance Adams had worked as an architect in Japan and Berlin when by chance in the 1997 she had an opportunity to apply her skills to the design of buildings in space. Hired by Lockheed-Martin she soon became deeply involved in the design of an inflatable module called TransHab (short for transit habitat) that would provide a "residents hall" for astronauts on the International Space Station.

Carried in a compressed state in a single shuttle and inflated after reaching the Station, TransHab would provide an enormous amount of space compared to that available in the other hardshelled station modules. The interior holds three roomy levels, each serving a different function (see figure to the right). For example, the lower floor holds a dining area with a large table where astronauts can gather and enjoy a fine space meal together.

The multiple layers of Kevlar and other sturdy materials provide excellent micro-meterorite protection and leakproofing. Water tanks surround the middle level where the living quarters reside, giving substantial protection from radiation. Two one-third meter diameter windows allow views of the earth and stars.

TransHab Cutaway veiw
Cutaway view of the TransHab large volume habitation module. The three levels include a wardroom at the lower level, mechanical room and living quarters in middle level, exercise room and shower in top level. Tunnel entry to rest of station at top. (Larger image)

Lightweight yet providing large and useful volumes, such inflatable structures clearly offer great advantages for space stations and also for building bases on the Moon and Mars. Many space advocates recognized, as well, that TransHab type modules could allow for quick construction of orbital space hotels and other facilities to house large numbers of people.

Unfortunately, the big budget shortfalls and delays in the ISS project, along with various political machinations, led Congress in 2000 to restrict NASA from spending any money on TransHab beyond the design studies. Even worse budgetary problems since then led to the indefinite delay of the installation of even the default hardshelled habitation module.

See this Houston Press article from August 2000 for an interesting history of the project and the role Ms. Adams played in it. This report by student at Embry-Riddle University provides a good summary of the technical aspects of TransHab. (More links.)

I managed to find Ms. Adams via the Net and she generously agreed to answer some email questions about TransHab. We also discussed the general challenges of designing structures for space and how an architect applies her skills to aerospace projects. I've assembled the interaction into an interview format here.

HS: As I understand it, Transhab is no longer in development due to NASA's funding shortfall for the ISS and Congressional restrictions. Is this correct and are you working now on any other projects involving large inflatable space structures?

Adams: The ISS-TransHab project was intended to perform the design studies and engineering tests necessary to prove that an inflatable module could be used on the International Space Station as a habitation module for the crew in place of the ISS-standard hard-shell module originally proposed for that purpose. In that narrow sense, then, the project was extremely successful and ran its natural course, since its formal goal was simply to prove the virtues and viability of the inflatable option.

Many trade studies were then performed to determine which choice would better suit the ISS’ immediate needs and current budgetary constraints. In terms of long-term and operational costs and needs, there was no question that the ISS-TransHab module would save the program tens or hundreds of millions of dollars over the first decade, and would give the overall Station several assets that it does not and could not otherwise have. These included a safe-haven shelter for solar storms, on-orbit water recycling capability, more than double its current total stowage volume, and the ability to test new exploration-class technologies like a human centrifuge, advanced medical facilities and lighting as well as the inflatable shell and orbital-debris shielding for which TransHab has become famous. NASA’s Human Exploration and Development of Space (HEDS) roadmap defines all of these technologies as essential developments for any long-duration human expeditions beyond earth orbit, such as a return to the Moon or the exploration of Mars.

However, you are right in understanding that the discovery in early 2001 of a $4.8B shortfall in the ISS budget has had wide-ranging effects in America’s overall space program, almost all of them very damaging. One of the first things to be cut from the program was the habitation module and supporting elements of the ISS, including the Crew Return Vehicle which would be necessary to allow the crew to grow from 3 to 7.

Currently there are no NASA efforts I know of to develop any space inflatables, but this does not rule out the possibility of recovering this program if and when the funding scenario changes or another mission is found for similar vehicles.

I am myself working on design ideas and scenarios for the next generation spacecraft, including the Orbital Space Plane, including a new concept for heat-shielding to reduce the risk of recurring damage like the Columbia scenario..

HS: In one article I came across, the reporter said that you and the Transhab group managed to overcome major obstacles that had stymied previous attempts to build large inflatable structures. Can you tell me about some of those obstacles and what were the solutions that made Transhab practical and affordable?

Adams: The biggest two challenges facing space inflatables were the strength and safety of the inflatable shell, and the need for firm structure to maintain form and allow the attachment of systems and other hardware.

TransHab attached to the ISS The TransHab module attached to
the ISS. (Larger image)

Both of the solutions involve patents filed by the TransHab structures team, so my ability to discuss them is limited. However, I can say that the strength of the shell is dependent on a specialized weaving pattern that permits straps of woven Kevlar to withstand remarkable amounts of stress. The final TransHab test unit withstood over four atmospheres of pressure differential (54psi) before the test was stopped; it has to date never been made to fail under similar tests.

The ability of TransHab to maintain its shape and support equipment attachment is due to its endoskeletal structure. In other words, like us it has a hard internal structure that helps it keep its shape and to which its systems equipment is attached, allowing its outer shell to do its job without interference. This hard core structure is made of light composite elements and allows TransHab to be secured in a shuttle’s payload bay or on other launch platforms in a deflated, cylindrical form prior to its inflation and assembly on orbit. .

HS: When I see photos of the interior of Mir it reminds me of my days doing research at particle accelerator labs. We would spend endless hours in the experiment control rooms that were packed with electronics racks, cables streaming everywhere, piles of manuals laying all over the place, and loud cooling fans running constantly.

Not great working conditions! However, at least we got to go home occasionally. Living in that kind of environment 24 hours a day for several months could become a nightmare.

ISS was supposed to be different than Mir, but recently I read that it has started to become just as cluttered as Mir with equipment scattered all about, walls covered with stuff attached to Velcro, and so forth. On top of this the noise levels are much higher than expected.

Do you feel a bit of the "I told you so?" when you hear such descriptions of the ISS? Besides the fact that Transhab was simply more voluminous, what was there about its layout that would have encouraged a more orderly, productive, and pleasing environment to live and work in?

TransHab wardroom
TransHab wardroom. (Larger image)
Adams: So far, the technical complexity of safely operating a spacecraft is the single overriding factor in human spaceflight, and the importance of keeping risk to a minimum means that a system or method that has proven its worth in flight is likely to be reused rather than substituted for something new. This is sound thinking, but of course it means that lots of new projects don’t really start out fresh; they start out by inheriting all kinds of constraints from decisions that were made in the past. Those decisions may have been good ones, but often they were not made at a time when it was anticipated that they would become the basic architecture for so many other efforts in the future. Basically, the result is that almost everything starts with a work-around to allow it to fit what exists.

In response to your question let me suggest without any kind of criticism, that very few of the things you say about living and working conditions on ISS were a surprise to the people who have been working on crew systems and human factors for years. Remember that the basic US ISS architecture dates to the mid-80s (and the Russian modules date to the Salyut stations in the mid-70s), so by the time the first modules were launched in 1999 there had been plenty of time to anticipate issues. The problem the human-systems folks faced then were the same ones they have always faced: the first and last decisions are made by Engineering, and it’s generally understood that clutter and noise are pretty minor problems compared with the hard vacuum and 500-degree temperature fluctuations of outer space. They knew these things were coming at them, and as hard as they tried to get attention to the problems, in many cases there just wasn’t anywhere for the program to budge to resolve them.

This is why TransHab was so exhilarating for most of us: it was new, and we had an opportunity to make all its rules while implementing lessons we had learned from previous designs and programs. One of the most radical changes was in process: there were Architects at the core of the design from the beginning. Rather than approaching TransHab’s design as first a structural problem, then a systems problem, then an “outfitting” problem, as has always been the process before now, TransHab had experts on its design team that agreed to look at all those areas simultaneously. One of the arguments we used to keep that focus was that, in the world of human spacecraft, our end product would be worthless if it did not.

HS: If NASA started a new Transhab type project today from scratch, what changes would you recommend?

Adams: Probably the only really important thing I would recommend would be not to re-start the project “from scratch”, but instead to reassemble the TransHab design team and let these great people have a chance to finish the work we started.

I have been surprised to find how many studies have been done over the last four decades for all kinds of vehicles, including a Crew Return Vehicle, Mars habitats, space stations and lots of spaceplane concepts… yet very few if any of those studies have the opportunity to contribute to the next phase of the project, because they are buried in obscurity unless the engineers who wrote them accidentally end up on the subsequent design team.

TransHab construction
Cutaway of the TransHab shell showing the various layers. (Larger image)
  Of all the extraordinary things that the ISS-Transhab project’s funding delivered was the project team, who learned in the hard, old-fashioned way how to design and verify a new human spacecraft. After two hard years of developing our design, our team had the immense challenge and great good fortune of presenting our work to an Independent Technical Review board that consisted of men who had led the engineering and design of most if not all American human spacecraft and missions. For two and a half of the three days that we met, these guys tore apart every sentence we spoke, and worked our knowledge of our vehicle, its materials and methods to the limit; and on the end of the third day, they passed us with flying colors and praised our work as a project team.

Losing that team is the thing I regret the most about the end of that project, and it would be a terrible shame if anyone contemplating the continued development of an inflatable module did not at least try their best to reassemble those very people for the next level of work. In terms of intellectual capital, the TransHab team was built by the money the American people put into TransHab, and was tested and approved by important representatives of the only other American generation to have designed, built and flown any vehicle meant to support humans in outer space. I think of many books that have recently been published, including Chris Kraft’s autobiography Flight and Gene Kranz’s Failure is not an Option, and need go no further to support this idea. One of the things Kraft keeps emphasizing in his book is how much more complex a spacecraft is than any other kind of vehicle, and how much more difficult it is to develop one than any of them had imagined. I can attest to that. It’s one of the truest things I ever read. Many talented, smart, hardworking and experienced people dream of working on space hardware; but until you’ve done it, I don’t know that it is possible to understand just how much harder it is to do.

What worries me is the thought that this country might be in danger of losing the greatest technical capability it has, if it waits too long to start committing itself to building the next generation of spacecraft, because the know-how developed by trial and fire in the 60’s and 70s is almost gone and very few people of the current generation have had the opportunity to learn from them how to do what they did. The TransHab team became, almost by accident, one of the very few seedlings planted by those great old trees.

Resources related to space architecture

* Space Architecture
* Space Stations
* TransHab
* Inflatable Structures
Space Lodging
* Space Life
* Space Settlements

HS: The primary goal I have for HobbySpace is to help change some of the common misperceptions that people have about space such as the belief that amateurs cannot contribute to space development. (See my site for proof that amateurs have in fact made big contributions.)

Adams: You are absolutely right about that! In fact, even some of the most famous “space technologies” were not developed by NASA, like Velcro and Teflon… they were developed by garden-variety inventors, but until NASA needed something and went looking around to see if it was out there, they weren’t selling. Then, later, their usefulness was clear to everyone.

Especially today, when the NASA budget is kept at starvation levels, the need for independent enthusiasts to pursue ideas that may end up being useful to space exploration is as great as ever. Hobbyists should also take particular interest in the fact that, of all the various skills and training we believe the first Mars expedition astronauts will need, the ability to tinker and have an innate sense of how to fix things is at the top of the list. The value of that idea was proven during the first ISS crew, when Bill Shepherd, the Expedition One commander, was selected for that job. He is a famous tinkerer, and legend has it that his dining room table is always covered in tools and projects; and nobody could have been a better choice for his job because all kinds of things that came up as surprise issues needed fixing, and he worked like a demon but got it all in great working order. So, while it not get you into the Astronaut Corps all by itself, a penchant for inventive tasks could help get you to the stars!

HS: Yes, robot spacecraft certainly can't compete with people when it comes to on-the-spot problem solving. Don Pettit on the recent Expedition 6 mission, for example, showed the kind of resourcefulness that is common in scientific field work when he rigged up a "barn door tracker" with a cordless drill for taking pictures of the earth as it moved beneath the station.

With regard to enthusiasts contributing to space development, I would urge you to consult with the Mars Society on their Analog Habitats projects. I'm sure they they would welcome your input when designing follow-on projects to their Arctic, and Desert habitats . I think inflatable habitats would offer a number of advantages.

HS: One common view of living in space, for example, is that it would be just like living in a submarine - dark, dank, and claustrophobic. With Transhab we see in fact that a space habitat can have large open areas even at this early stage in space development. Dealing with a one atmosphere pressure difference is a lot easier than dealing with many!

Adams: Well, or even less: although ISS is pressurized to sea-level at 14.7 psi, the Space Shuttle is usually only pressurized at 10.2 psi, and Russian space stations even lower, at a range between 4 and 8 psi. In its vacuum test, the TransHab shell had assumed its full shape by the time it had only 0.5 psi! We were amazed.

Still: I’m not sure what the relationship between the first and second part of the question is, though; the pressure environment isn’t the only thing driving the architectures in question. Well, inflatables are not likely to be very useful under water if that’s what you mean… although I remember hearing there was some talk of using a TransHab type inflatable as a portable decompression chamber for diving teams. That’s not the same thing, but it would permit rapidly-rising divers to be placed into a high-pressure environment inside the inflatable as soon as they are back on deck, I think. In any event, if your point is that inflatables are mainly useful when the desired pressure differential from inside to outside is negative (i.e., when the pressure inside is higher than outside), then you are of course correct.

Something like the opposite of an inflatable is necessary under water; and maybe we have been sort of fooled by the accident of cylinders being used both for spacestations and for submarines, into thinking of them as similar conditions. This is an interesting point of departure for a whole new level of thought about paradigmatic forms for different environment.

HS: Another great benefit I see in living in space is that one has the sun for company up there. Large windows would be nice but they are not very practical structurally and lousy for radiation protection. Would it be feasible, though, to use light piping with either fibers or chevron mirror arrangements to distribute light throughout a Transhab type structure?

Adams: Various versions of these ideas have been looked at; there are still a couple of stumbling-blocks, including the fact that a two-dimensional display is neither physically nor psychologically acceptable as a substitute for a window. There are literally hundreds of studies, mostly in behavioral psychology, demonstrating this. However, for many of the reasons you have already identified, it would certainly be a tremendous advantage to succeed in developing these systems as an enhancement to the environment, and perhaps thereby keep the number of windows to a minimum.

Mir 18 crew Vladimir Dezhurov (left) and Gennady Strekalov (right) at Mir communications console.
(Large image)
More at Mir Space Station

Video was used, for example, to allow the cosmonauts to control remote docking of the Progress resupply capsule to Mir; and because of various possible glitches like EMP hits or other fields that can interrupt transmission of signals, or maybe just failure of a camera or an antenna, the big accident of July 1997 happened because the commander on Mir was flying blind. He couldn’t actually see the Progress because he had no window near his controls, and the video was illegible.

Many near-accidents in our own space program have been averted by the intervention of skilled pilots using their windows and whatever controls they had available to find solutions when automated systems broke down. It’s funny that, despite the repeated lessons in human spaceflight that continue to point to the value of the trained human operator with direct visual contact and mechanical control, somehow the public continues to subscribe to the “Spam-in-a-can” theory of astronautics. Think of “Apollo 13”: those guys would never have made it home without some windows through which to use visible bodies as guides for their burns.

Although I started working in this program as an architect and human factors expert who insisted on the importance of windows, my experience with BIO-Plex and TransHab taught me to understand what the engineers fret about when they are required to include one in their vehicle. The level of risk that is latent in that product is much higher than if no window were present. BUT: in the long-term use of the spacecraft to perform its mission, it seems to have been proven by history that the best and most reliable redundant emergency system you can have is a human who knows how to make it fly and has a window to allow failproof visual contact. It’s a tough balance. I think that a combination of the two will ultimately be the best balance for long-duration flights.

HS: I certainly would recommend including real windows for all the practical and psychological reasons that you mention. I attended a lecture by Dennis Tito and he said he nevered tired of looking out the window at the earth and watching its infinite variations in geology and weather patterns. He showed many amazing "slides from his vacation".

I just meant that piping in sunlight could both save energy and provide the kind of light that we find warm and invigorating. A possibility not available underwater.

On the other hand, a room with a large "Star Trek" viewscreen could be quite enjoyable as well. Besides displaying views of the earth and stars (and Klingon cruisers!), I've wondered about whether it would be feasible to use other sensor data to display, say, the ebbs and flows of the solar wind so that even the vacuum doesn't seem so "empty"!

HS: Sunlight would have great positive psychological benefits. I can envision, for example, a large "sun room" to relax where one could select filtering of the piped in sunlight to produce, say, a bright day at the beach or a midsummer sunset. .

Adams: Great idea!

HS: For space tourism the visitors would obviously prefer such an airy, well lit "space hotel" to the Mir or even ISS environment, which bear a resemblance more to the cramp service tunnels running underneath a hotel!

Adams: I disagree. Beaches, we have here on Earth. What tourists cannot get on the Earth is a view of outer space: the stars, our Moon, the beautiful Earth. Too much sunlight would drown out that view, just as streetlights generate too much light pollution down here for stargazing in many regions. As for open space, a short visit in space is typically characterized by an initial phase of space adaptive syndrome (SAS) which can be really disabling for some days, followed by a real difficulty learning to use their bodies without gravity. Just getting dressed in the morning can take an hour of terrific effort unless you are in a cozy corner against which you can prop your limbs. So, while some large volumes might be fun, the space tourist’s needs in terms of volume, form and function are not necessarily compatible with the needs of a long-duration crew who are working 12 hours a day on orbit for months at a time.


HS: Yes, I definitely believe a space hotel should certainly offer more than just a duplicate of an earth hotel. However, I believe it could offer many experiences. One section might provide a sunny open area while other sections could offer cozy rooms with glareless windows looking at the stars or the earth. Similarly, when rotating stations are developed, the outer areas will provide some fraction of a g, while the axis areas provide a weightless experience.

The SAS question is an interesting one that space tourism operators will need to deal with and a great area of research for NASA, but it's certainly not a showstopper. Tito had a few minutes of nausea in the Soyuz on the way up to the ISS and that was all. Shuttleworth I believe had a slightly longer period of adaptation but it was no big deal. Senator Jake Garn, on the other hand, at least according to rumors, took a few days to acclimate. So it seems to vary a lot with the individual.


HS: I believe that Bigelow Aerospace is planning to use an inflatable structure for its space tourist hotel. Are you familiar with their plans or any other commercial project with inflatable structures?

Adams: I think Bigelow has disbanded that team. But even if not, it’s not really appropriate for me to discuss their project.

[May.31.03 - I've been informed that Bigelow is still working actively on inflatables. See the note below.]

Budarin on the ISS
Cosmonaut Nikolai Budarin in
the Zvezda Service Module
(larger Image)

HS: An architect tries to design living and working spaces that not only serve the obvious functional requirements but also create an environment that brings out the best in people, even though many of the beneficial features may be subtle and indirect.

Adams: Actually, very few architects worry about the subtle and indirect experiences and well-being of the building’s users. This is a new specialty, which some practitioners call “evidence-based” architecture, and others call “high-performance architecture”. The reason, I think, is that Architects are trained as integrators and designers, civil engineers and artists… and in balancing all of that, there is an assumption that the users will appreciate the building. Being happy in the building is not usually the same thing; and because Architects are not scientists, they do not feel a need to rely on quantitative data for environmental design.

But design of medical facilities really requires that the architect get involved with the client’s goals, i.e. in encouraging healing, and that has led to the “evidence-based” design movement. Spacecraft fit into the high-performance category, because they are functional machines and the performance of every part of them—including their crew—comes under scrutiny as a major criterion of their success.

HS: I was wondering if you had some culture shock, or at least a lot of arguments, when working on a project like the Transhab with, forgive the stereotype, hard nosed engineers who just want to "build something that gets the job done"?

Adams: Architects aren’t dilettantes; we all want to get the job done, and unlike many engineers, a project’s Architect often carries sole and personal legal liability for every building they stamp. So getting it done and done right is a common goal. Actually, during the times when I have been busiest in the space program I found myself participating on engineering project teams that were vastly more cooperative than most architecture groups, and with less ego flying around. The most important operative aspect of the NASA work environment is the emphasis on the idea that “no question is a stupid question.” That was never true in any other environment, social or professional, I have ever been in; yet if something as insanely challenging as a spacecraft is going to be built and fly safely, it really is a fundamental ingredient of the workplace.

The main challenge is always in teaching my engineer colleagues how an Architect works, and how we can help them, not compete with them. Typically, engineers are trained to work in a linear fashion, whereas architects work in a sort of holistic or concentric fashion with the project progressing from the center of the tree to its bark. Getting these processes to work together means helping each of the people following a radial process to understand the integrative function the architect performs on the team. But once that hurdle is past, it’s really wonderful to see how well a team can work! I am now beginning to try to explain this process to Architects, and it’s harder than you might think.

Anyway, I am working on a book right now about NASA and how it really is the last holdout in our civilization of the culture of Great Projects, a place where everyone works because they believe in the goal, in the end-product, and not for some personal gain. It is the best kind of culture-shock I can think of, to come into that environment after the empty competitiveness of private industry. One of the things I will remember best was the feeling I had the first time I went back to New York to visit friends and old colleagues after starting work at the Johnson Space Center. Where I expected to feel like the country bumpkin returning to the Big City from swampy Houston, instead there was this interesting reversal. Even when talking with or about old friends who were working in the coolest offices or for the most interesting clients, I realized that what they were doing was beautiful and publishable and expensive—but it wouldn’t likely matter to their great-grandchildren, and it probably didn’t even feed their soul today. For a big change, I felt that I was the fortunate one because every stupid little thing I did at work made some kind of contribution to what I believe will be the future of humankind. Hopefully, for the better!

Apparently this kind of value doesn’t matter to most people; but to those of us who do need to feel that our work has a greater significance, there is no greater pleasure than working in a program like the Space program.

HS: I certainly understand your enthusiasm and passion for such work. Thanks very much, Constance. Best of luck with your new projects.

The members section at includes a brief resume of Ms. Adams.
See also the summary of her lecture Space Architecture After ' 2001'
given in November 2001 at the Architectural League.
You can contact Constance Adams at

TransHab attached to the ISS provides an extensive reference list of papers and articles
about space architecture, many of which are available on line.


Mar.21.04. Constance now has two other web sites: synthesis international USA and the MOTHERSHIP

Jan.16.04. Constance offers a lot of excellent suggestions for NASA in this essay: It Doesn't Take a Rocket Scientist by Constance Adams - Popular Science - Feb.04 issue. The article also included sketches of the TransHab module as it progressed through the design process: It Doesn't Take a Rocket Scientist - Transhab development sketches

June.3.03. I've been informed my Tony Rusi, a former employee of Bigelow Aerospace (includes links to articles about Bigelow), that the company is very actively working on inflatable structures: "They have not disbanded, but they are a very small organization. In fact, they are in the process of full scale hydrostatic tests of a Vectran edge-sewn and arc-sewn narrow webbing pressure shell." ...

..."The cheap revolutionary manufacturing process Bigelow uses could make a pressure shell of almost any size for future space colonies, hotels, and ultra-large compactable propellant tanks. Others have used weaving, braiding, fiber placement, and filament winding machines to make flexible pressure vessels. All these other methods require expensive new design, for single purpose machines, that will take millions of dollars and years to set up."


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