How Do You Build Your Own Functional Pressure Suit?
I started my first notebook on building my pressure suit in late 2008. Since then I have spent a lot of time building and testing my system--I teach at university and have several writing projects going at any time, so I can only really work on weekends, and some weeknight hours.
In that time, I've learned a lot about how to build a complex system. That is really the first lesson: that if you want to build a complex thing, you have to understand that it is a system, an assemblage of items that are meant to work together. So, you have the whole, and its many parts. Being able to think clearly on both levels is important. For engineers and others who actually build things, these notes probably won't be anything new. For those new to building things—in particular complicated things like pressure suits—these principles should be useful. They have certainly worked for me.
Here I don't reveal any specifics of my pressure suit design; if you want to build one, great, and you can email me to ask for details and I will be happy to provide details--I can't provide them all, though, as that is an entire book, and, anyway, the thrill is in building it yourself! I recently explained to Kristian at Copenhagen Suborbitals that I could have moved much faster with my build if I'd simply approached engineers for advice. But the point for me, in this project, was to learn how to build the pressure suit myself, through a very fulfilling and exciting learning process. That process, I've found, has been rewarding, whereas just getting the answers from others would, frankly, be boring (in hindsight I also understand that many of those advices would have been contrary to one another!).
After several years of building, I have recently had a few engineers review my pressure suit system, and I've been thrilled to find that unanimously they have found it, in principle at least, entirely reasonable. I have also had (a) no 'blow out' failures, that is elements of the build failing catastrophically during any pressurization (up to 4psi) of the mature system and (b) 100% success of the suit in a 7-minute test, underwater. The system is crude, but working. That reminds me of the words of aeronautical designer Bob Parks, who wrote:
“Any damn fool can figure out a better way to do it...get it good enough, and get on with it.”
Keep in mind that while guidelines are useful, we must not enslave ourselves to any dogmas; guidelines are suggestions, not shackles. Creativity, it's increasingly recognized, is the capacity to connect previously-unconnected ideas in a way that works towards a goal (even if that goal is nebulous). Adapt these guidelines to your own project.
Good luck!
1. Forget Preconceptions.
Just because something has been built in some way does not mean there aren't other paths to that same thing. Many products are built not for efficiency or excellence of design (in fact many are built to fail after some period, so that people will purchase more). Actually most of the objects we use every day--from screwdrivers to the simplest dining chair--could be redesigned to be better.
Break out of the ruts of habit. Example: At first I tried to copy American pressure suits, which use heavy, complex and expensive airtight zippers; but research showed me that the Russian Sokol suit (proven reliable over decades, now) uses a lighter, simpler and far cheaper pressure closure, a design that also allows astronauts to put on their own suit without the help of technicians. Though I'm using an airtight zipper in my 'Gagarin' model (for my own stratosphere expedition), in later models I will switch to the superior (in my view) Russian Sokol pressure-sealing system. If I hadn't read far and wide, breaking out of what I thought a 'pressure suit should look like', I would not have known about that Russian system.
2. Break the Task Down.
You can easily be overwhelmed by a project unless you break it down into component parts and specific tasks. Think clearly to identify the various systems, and tackle them separately. Later you can work on 'system integration' but as long as you are not 'hard wiring' in specific fittings etc. to make the system work, you will be OK. Example: I am often overwhelmed by the project, thinking about how X will work with Y. My solution is to keep making checklists that disassemble the project into manageable parts. One of my checklists (rather lengthy) from a few months ago is shown below, demonstrating how I take the project on, one part at a time. Each of these items took at least an hour (and often more) to complete, but each time I 'knocked one out' I moved the build forward. It is a good feeling to strike items off of a checklist, showing you that you are moving ahead!
____HELMET
- seal / remove helmet exhaust valve
- arrange intake hose warm-air defog unit
- spare UV/IR cover cutouts
- extend brow of liner cap
- reseal helmet / ring interface
- paint helmet with antiflame coat
ORAL-NASAL MASK
- add velcro connections to helmet liner cap
- ensure proper hose in / out lengths
HELMET HOLD-DOWN CABLES
- replace buckles with metal
- remove / secure sharp swage ends
GLOVES
- second hose clamp each
- hose clamp hold-downs
- anti-stretch gauntlets
CHEST FITTINGS (final tighten of all fittings)
- left = breathing gas out / extend hose
- center = electrical + comms / shorten through-fitting and epoxy in lines
- right = breathing gas in / attach quick fitting and attach hose hanger clip
ABDOMEN FITTING (final tighten of fitting)
- left = cooling hoses in + out / attach hose hanger clip
LEG FITTINGS
- left = suit pressurization gas in / replace fitting or test for slow leak at SCUBA shop
- right = suit pressurization gas out / attach larger control knob
HELMET HOLD-DOWN CROTCH STRAP
- reinforce
KNEE PATCHES
- add final grommets to each / add velcro position holders to each
BOOTS
- final airtight coat
PRESSURE RESTRAINT GARMENT
- center chest through-hole
- reinforce all through-holes with third strength layer
- cinch underarm mesh
- replace helmet hold-down cable rear fittings with metal
- replace chest fittings with metal
FIREPROOF COVERALL
-build and attach with arrangements for parachute harness
- add arrangement for bail-out aviator's breathing gas cylinder
- add arrangement for inflating life vest, sea dye and small survival / map kit
LINER COVERALL
- sew vest tubes for threading in coolant hoses
- sew socks on to leg cuffs
- sew thumb loops onto arm cuffs
3. Make Steady Progress.
This is related to the previous point; sometimes I will go a few days without making any progress, and that feels wrong. Even if I only do one small thing per night (or, often, one thing per weekend), I work hard to keep moving forward; crossing items off of the list feels great (see above), showing me that I am getting there (the list above is typed, but actually is hand-written in a notebook, where I use a marker to dramatically 'strike out' each item as I build it, noting the date of completion). Example: When I have to wait for some money to buy an expensive part, I shift my focus to small, cheap items I can 'knock off' of the list. My question, daily, is “What can I do today to move forward?” Even the smallest item off the list is an item off the list.__
__
4. Get it Working.
It's easy to get bogged down by trying to perfect details. For a proof-of concept project, get the sub-system working, and move on to other sub-systems. Example: for the liquid cooling of my suit, I am currently using a $15.00 aquarium pump to circulate ice water through hoses sewn into the suit liner. This works, but of course later I'll replace the pump with a more durable one, and replace the ice water with an antifreeze--but these subsystem replacements will not involve significant re-engineering of the whole system.
5. Learn From Your Mistakes.
I make mistakes all the time—90% of the materials I've bought and designs I've tried have not actually worked—but I keep notebooks of my tests and building (see below) that allow me to learn from past experience. A good attitude calls a mistake a 'learning experience'. I certainly get tired of these 'learning experiences' from time to time (see below, 'Have Fun With Tests'), but then I remember that if I log those test failures, they're invaluable knowledge. Descending the terrifying mountain K2, mountaineer Mark Twight once dropped his team's tent: making lemonade from this lemon, he thought, “Well, I don't have to carry that anymore.” I take the same approach: I know a lot of approaches, now, that don't work, and now I know that I don't have to think about them anymore. Example: I spent months learning that no matter how well I prepared textile surfaces and how long I clamped textile surfaces together to bond them with glue, no adhesives were going to work to keep the pressure in the suit: today I know now that they all textile seals must be mechanical closures. That's a simple but invaluable lesson. Again, pressure-suit engineers might have told me that years ago, but there is just nothing like experience to really drive an idea into your overall thinking. I won't make those mistakes again!
6. Learn From Other Peoples' Mistakes.
Research is critical; even if I have subsystem 'worked out', I keep reading about other peoples' experiences with those systems, and learn from their problems. Example: In the 1930's a Soviet balloonist parachuted from the stratosphere in a basic pressure suit, but was found dead on the ground, with a cracked helmet visor that had depressurized his suit; during Felix Baumgartner's recent jump from over 120,000 feet, I carefully wrote down each of the 30+ checklist items the ground crew read up to him to prepare for the jump. I noticed that one item was to bend low as he moved through the hatch, to be sure he would not bang his visor on the hull and crack that visor. You can bet that item is on my emergency bailout checklist (I don't plan to jump out except in an emergency).
7. Read Patents.
Reading patents, for a non-engineer like me, can sometimes be excruciating, but also extremely instructive (there are many ways to access patents online). Reading patents and looking at their illuystrations, you learn the principles of complex components and better understand how each component of the system works. This is important to prevent building in 'black boxes' in your design (see below). Example: I recently looked at the patent for one of the breathing regulators I am building into my system; although it just confirmed my suspicions of how it worked, knowing that I was right about that is important because it helps me to understand the entire system, with no gaps in my knowledge; that can help in troubleshooting during flight (see below).
8. Get Rid of 'Black Boxes' and Understand Your System.
To really understand how a system works, you must how each of its components works; for me, this means looking into the patents for each complex item I use. It's easy to just build an item into the system, and 'let it do its work', but if you don't understand it, you might easily mis-diagnose a test failure! This is important. I get nervous about items in the build that I don't understand, so I don't let that happen, and with research I eliminate 'black boxes', items that do something in a way that I don't understand. Example: I have carefully taken apart, and then reassembled, items as complex as breathing gas regulators, to be sure I know how they work, in a hands-on manner; recently this allowed me to identify why one breathing gas regulator was working while the suit was not pressurized, but failed when it was pressurized (this is a problem I'm still solving).____
9. Keep It Simple.
Systems are composed of components and their interactions; most times, the simpler you can keep the system, the less likely it is to fail. A fine line is walked, here, though, as simpler systems might be so crude that they are heavy, for example, or overbuilt for your purposes, while lighter (but more complex) alternatives are available—so don't overdo it! But, essentially, if I can get away with less items in a subsystem, I do so. The fewer items in the build, and the simpler each is, the less likely (in general) they are to fail. Example: I admit that I keep wanting to add buzzers, alarms, lights, and so on to my electrical system, because everything I know intuitively about cockpits suggests that they should be complicated. But my recent research into modern cockpit design suggests that cockpits should be less complex and more efficient (recently Kristian von Bengtson reiterated this point to me when telling me about his cockpit design, saying that he would eliminate displays of information that the pilot cannot actually use to solve problems). So, I am reducing electrical systems, rather than increasing them, and this is making me more value the simpler design than the more complex.
10. Have Fun With Tests.
I work mostly in complete isolation, often late at night and through entire weekends (I listen to a lot of old radio shows—which are nice because they introduce human voices into my work environment—and a lot of music; I also often listen to nature sounds, like a rainstorm or a beach, to introduce sounds but not rhythm or lyrics, which can be good for some tasks and which I personally find very calming). Because of this isolated, strange work, it's important for me to occasionally do a test not even to test a new subsystem, but to just get me in the suit and working with an assistant (another human being!), because it's fun to be in a pressurized suit and to talk with other people! When the system build occasionally gets to be a drag (as after I've had failure after failure) sometimes I just spend some time in the seat working the systems that I know do in fact work, to rebuild my confidence and enjoy the experience (after several years of working alone I have internalized the old adage that 'it's the journey, not the destination'; while I am in fact focused on the destination, I understand that I should keep the journey enjoyable!). This is particularly important to keep up morale while building something improbable! After a test, even a 'failed' test, my body is rushing with adrenaline and my mind is buzzing with excitement. It's important to keep these in the works when I am otherwise fiddling with the finest adjustment of a screw, or tracking down an electrical short-circuit. Example: Recently I did an 'immersion test', taking the pressure suit into a swimming pool. With the help of some other divers we put me into a seat weighted to the bottom of the pool, strapped me in, and then brought the suit up to 3psi, depressurized it, brought it back up to 3psi, and so on. This was a great test to find leaks (rising bubbles), but it was also just a lot of fun to get the suit out of the shop and test it in a new environment (the test went well, with no leaks where I expected leaks---video of that coming before long!).
I hope these notes will be useful for anyone attempting to build a complex thing. I wish all builders the best luck, and plenty of learning and fun!
Cheers
Cameron
Dr. Cameron M. Smith is an anthropologist at Portland State University with extensive experience in exploration. He is currently building his own pressure suit for a personal balloon ride to 50.000 feet and has recently joined Copenhagen Suborbitals. Cameron is 45 years old.
