What are spacesuits made of? The evolution of the spacesuit with Dallas Campbell By Dallas Campbell, 2015 Honorary Fellow of the British Science Association-------This blog is part of our series of space blogs for World Space Week; Hear the soundtrack for space exploration, listen to an audio tour of the active missions in the solar system, and uncover what the discovery of flowing water on Mars means for future missions.For the last few months I’ve been happily sharing my home with two second hand spacesuits. One used by Michael Foale the British born American astronaut, and the other by Alexander Kaleri the Russian cosmonaut used on a mission to the Mir space station. They’re Sokol (Falcon) pressure suits made by NPP Zvezda in Moscow and are the type currently worn by all astronauts including Tim Peake later this year. I’ve enjoyed having them in my life, and everyone loves looking at them. When they’re laid out flat they resemble wrapped Egyptian mummies, a shape-memory frozen in time like empty cocoons, cast-off snake skins, or empty crab shells. As well as being visually arresting they have a really specific smell which always hits me as I walk inside, like the smell of an old friend. They are currently enjoying a second life as fascinating show & tell objects (I’ve done a lot of showing and telling), with a great story that encapsulates much about science, history, adventure, fashion and engineering. A spacesuit is really a wearable spacecraft made from a variety of materials depending on the job they have to do. If they’re the bulky EVA (Extra Vehicular Activity) suits used for space walks, or exploring a planetary surface they have to provide the toughness of a suit of armour with all the other considerations that the harsh environment of space will throw at you. And they have to be flexible & comfortable enough to work in. I recently visited the Smithsonian Museum in Washington D.C. & got the chance to look at some of the iconic American suits up close. Once again I was hit by that Proustian smell/memory: a rubbery, metallic, ‘military’ smell with ‘aircraft seat fabric’ top-notes is the best description I can do. In a laboratory in the museum, laid out like a corpse on a metal gurney, was one of the gorgeous Project Mercury suits - slim and tailored with that famous silvery aluminized coating and orange lining. The silver colour intended specifically to give them that Buck Rogers appeal as military pilots were re-branded in the public eye as a new breed of super hero. Next to that was the most famous spacesuit of all - The multi layered A7L Apollo suit. This particular one worn on the moon by Charlie Duke (Apollo 16). The outer skin of the suit is white Beta-cloth - a Teflon coated woven silica fabric, still stained a dirty grey from the all pervasive moon dust. I peered through a microscope at the weave & the stitching to see how it’s been constructed & how it’s been damaged by the abrasive dust and time. The history of the spacesuit dates back to the 1930’s when aviators were tentatively making the first exploratory steps into the thin hostile environment of the upper atmosphere. The American record breaking aviator Wiley Post set himself the task of creating a pressurised protective garment for his forays into the jet stream. Post enlisted the help of Russell Colley, (who went on to work on the silver Project Mercury suits) an engineer / women’s fashion designer working at the B.F.Goodrich company, to help him on this quest. And so began a story of engineering, material science & experimentation that continues to this day. The early Wiley Post suit was a Heath Robinson affair, three layers in all: a warm thick cotton one piece undergarment, an inflatable rubber bladder suit (essentially a wearable bicycle inner tube) which is in turn encased in a heavy canvas and leather trimmed overall. A basic welded aluminium helmet with a round porthole reminiscent of a Victorian divers’ helmet is screwed on to the overall’s leather collar. As we’ve journeyed further towards the stars, the materials used in spacesuits have became ever more exotic and sophisticated: Nylon, Spandex, Aluminized Mylar, Teflon, Nomex, Kevlar, Chromel-R, Beta cloth, polycarbonate, but the pressurised inflatable airtight bag philosophy has pretty much remained the same. That may be about to change as our steps towards humans on Mars will require ever more fiendish engineering solutions. There is a move towards skin tight suits applying direct mechanical pressure to the body rather than the inflatable Michelin Man look, but a Mars suit is fraught with technical challenges. Orders of magnitude more complex than even the Apollo suits. The Sokol suits enjoying their retirement in my home are beautifully crafted but really no more sophisticated than that first homemade suits of the 1930’s: A rubbery bag that you pull out of the chest and climb into. This is then scrunched up and sealed with a rubber band, no less. The tough outer suit is then zipped up with heavy metal zips and you’re ready to go. Gloriously low tech, like all good reliable engineering should be.With space travel you don’t want cutting-edge. You want it to work. And to look good, of course. Celebrate World Space Week- Take part in a space-themed CREST project or discover more about deep space with our space blog series.