As NASA's missions evolve to reflect changing ambitions in space, a small army of specialists - from materials scientists to zipper-designers - craft the clothing that allows astronauts to stay alive and perform tasks under unearthly conditions.
From the style factor of silver coating to the quest for the perfect glove, and from John Glenn's pressure suit to the space garments of tomorrow, take this timeline tour of treasures from the U.S. national collection.
John Glenn's Mercury-Atlas 6 Pressure SuitCourtesy of Smithsonian's National Air and Space Museum
On the morning of February 20, 1962, a 40-year-old Marine Corp test pilot named John Glenn closed his 27 zippers, climbed into the Friendship 7 capsule at Florida’s Cape Canaveral, and blasted off to hero status. It was in this suit that he became the first American to orbit Earth.
This suit, in fact, is not a spacesuit, as it was designed not for operation in the vacuum, but to provide backup life support should the craft’s system have failed. Suits for this and other Project Mercury missions were based on the Mark IV design that rubber giant BFGoodrich made in the 1950s for high-altitude Navy pilots. That suit, in turn, was inspired by the first pressure suits designed by aviator Wiley Post in the 1930s.
Why the metallic coating? Cathleen Lewis, spacesuits curator at the National Air and Space Museum, points to three possibilities: In case of an emergency, the reflective surface would help the astronaut be spotted for rescue. It was also thought that the surface would offer a thermal advantage, diverting light and heat. And, of course, there’s the style factor. “It was a distinctive look that reverberated with that idea of the high-tech space man from comic books,” Lewis says. (The real motivation for the metallic coating was probably a combination of all three, she concludes).
Gus Grissom's Gemini 3 Pressure SuitCourtesy of Smithsonian's National Air and Space Museum
Gus Grissom, one of the original seven NASA astronauts, wore this suit on the first of the manned Project Gemini missions, which made three low Earth orbits. The suit was based not on BFGoodrich designs, but rather, the flight suits that the David Clark Company was supplying to the Air Force. The craft, affectionately known as the “pilot space craft,” was more maneuverable, and astronauts needed a greater range of motion and vision for the extra activity.
When the spacecraft was pressurized and all was well, Grissom would have been able to remove his helmet. Otherwise, thank goodness for those connectors. The light blue port over the stomach supplied oxygenated air, while expired air would pass out through the red connector. The port above is for communication, connected to the life monitors – akin to an EKG patch – that astronauts wore all the time. A monitor on the wrist would track the pressure inside the suit.
No more silver! Several preliminary versions of the Gemini suit do have the coating, and were used for thermal tests on Earth, but they never made it to liftoff. Indeed, the discussion was ongoing as to whether the metallic coating would help astronauts avoid overheating in the cockpit or whether a white reflective surface would be adequate.
Eugene Cernan's Gemini 9A Pressure SuitCourtesy of Smithsonian's National Air and Space Museum
This is the first suit that is indeed a spacesuit, made for meaningful work outside the craft. The interior, seen at left, is a pressure garment assembly, meant to keep air inside. The netted cover functions as a restraint, so that when the suit is pressurized and the astronaut is in the vacuum of space, it will not blow up like a balloon.
The exterior, seen at right, is a thermal micrometeoroid garment, made to protect the wearer from the brutal elements outside. Built up of many lightweight, synthetic layers, it is designed to prevent small participles – traveling at about 17,500 mph – from penetrating the suit. The suit was paired with an Astronaut Maneuvering Unit backpack, which Cernan was supposed to test, until dramatic complications ensued…
“Gene Cernan came as close as anyone to losing his life in space because of what was going on inside,” Lewis says. In short, the astronaut was overheating. “He perspired an enormous amount – he lost as much as 10 lbs. during this mission. His visor became fogged and he couldn’t see anything; he was basically operating blind. Had not Thomas Stafford been able to literally pull him in by the legs and set him back down into the cockpit of the craft, he would not have survived.” Back on Earth, NASA engineers began investigating liquid cooling garments.
“The lower part of this suit is really a wonderful thing,” Lewis says. Designers, concerned about protecting Cernan from the hot exhaust expelled by the thrust of the backpack as he worked outside, used woven threads of high-chromium stainless steel, or Chromel-R. Highly resistant, the fabric would also prevent any abrasions. It was used in the Apollo program as well.
Neil Armstrong's Apollo 11 SpacesuitCourtesy of Smithsonian's National Air and Space Museum
This is the spacesuit that Neil Armstrong wore when he set foot on the surface of the Moon and became the first human to explore another world. “It’s the most famous spacesuit in common knowledge, but it’s not the most photographed,” Lewis notes. “The most photographed spacesuit is Buzz Aldrin’s, because Armstrong had the camera and Buzz was out doing the operation.” This was a suit that was going to do very different things than had been done before, she observes: “Not only were the astronauts to go out and operate in a vacuum, they were operating on another world. They were going to be walking, they were going to be bending over, taking samples, and scooping. So, it was necessary to design a suit with a full range of activity, and that required many advances and changes to what had been done before.”
This suit featured a much more sophisticated restraint system that would prevent astronauts from, for example, bending their right elbow and having their left jut out unexpectedly. A new type of helmet was also needed, as older pilot-style helmets did not give astronauts enough range of vision to see their feet – now a necessity for walking on the Moon. NASA engineers developed a pressurized bubble helmet based on aircraft windshields, much like those in use today. This suit was accompanied by a backpack – a portable life-support system – instead of operating on a tether, with life support coming from the craft. Armstrong’s lunar overshoes, with the rubber treads that left his famous footprints, remain on the Moon.
The final cost of the suit is difficult to determine, Lewis says. The initial figure was about $250,000, but refinements and adjustments meant that the final price was as much as $500,000 per suit. Moreover, each astronaut in the primary crew had a training suit, a flight suit, and a backup, and the backup crew had multiples as well.
At peak production, some 4,000 people at ILC Industries worked on making these suits, Lewis says. “That includes the seamstresses, the contract people, and the gluepot people who sealed the rubber seams. It also included the people who were in charge of taking the suits from Delaware to Houston to have them tested and having fit checks.” Measurements were particularly labor-intensive, she notes: “These are measurements far beyond what any Hong Kong tailor would take – for every dimension of their body, to make sure these suits were both comfortable and protective, but also allowing them to do meaningful work.”
Alan Shepard's Apollo 14 SpacesuitCourtesy of Smithsonian's National Air and Space Museum
Apollo 14 landed on the surface of the Moon on February 5, 1971. At age 47, Commander Alan Shepard became the oldest man to walk on the lunar surface – and he hit two golf balls while he was at it. This x-ray image of his suit was made approximately 15 years ago by a Smithsonian furniture conservator using technology that was quite pioneering at the time, enabling a new look inside.
Perhaps the most interesting component revealed by the x-ray is the crinkling in the arms, shoulders, hips, and legs. That is corrugated rubber, which allows the astronaut to keep the displacement of air inside the spacesuit very local, preventing the occurrence of a balloon-animal scenario, in which bending one arm would send the other shooting out.
The zipper – a key element of any spacesuit. This one extends from the back of neck ring and up between the legs, opening below the belly button. It is composed of two brass zippers with a rubber gasket in between, so that when the suit was under pressure, they would press up against each other to form a seal – effective even against lunar dust. One problem, however, was the lack of flexibility at the waist.
Eugene Cernan's Apollo 17 SpacesuitCourtesy of Smithsonian's National Air and Space Museum
On December 14, 1972, Gene Cernan became the last human to walk on the Moon. He did so wearing this suit, an advanced version of the Apollo 11 model worn by Aldrin and Armstrong. Containing a layer of aluminized, gridded Kapton film for extra protection against extreme temperatures, it also features red stripes, used since Apollo 13 to identify the mission commander. The suit also features a spiral zipper, thus avoiding the rigidity in the back, making use of the lunar rover more comfortable. Also note the new placements for the connector ports, repositioned to prevent the tubes from crossing each other.
Apollo 17 carried the only trained geologist to walk on the lunar surface, and also returned the greatest amount of rock and soil samples. That means pockets were a priority. In fact, they serve essential functions, holding checklists, notes, and caps to protect the integrity of the life-support connection. What resembles a pocket on the right knee is actually a Velcro patch that connects to the urine-collection device. There were also emergency and injection patches, which would allow the astronauts to use the spacesuit as an isolation chamber, if necessary, and to inject medication, such as antibiotics or tranquilizers.
Notwithstanding refinements, engineers and designers working on spacesuits tend to be conservative. Making changes adds risk. The boots on this suit, for example, were not fundamentally updated. Built very stiffly, with a steel shank on the bottom, they were made to measure for the wearer. Overshoes, made mostly of rubber, contained a thermal micrometeoroid garment and Chromel-R.
Spacesuit Assembly Extravehicular Mobility Unit (SSA EMU)Courtesy of Smithsonian's National Air and Space Museum
Technically, all suit iterations since the Apollo program are called Spacesuit Assembly Extravehicular Mobility Unit (SSA EMU). These three items are scrap materials, used during the testing process. The lower torso assembly seen here features another adjustment to the pesky zipper. One of the lessons learned from the Apollo years is that the copper in the brass zippers would eventually attach to the surrounding rubber, making it brittle – and endangering the seal. Instead, this suit features a hard seal, made of two pieces of metal that stick together. With no planned landings on extraterrestrial surfaces, and extravehicular work confined to the exterior of the International Space Station, there is no need for overshoes on these boots.
“The gloves are my favorite. You couldn’t tell the story of the spacesuit without gloves,” Lewis says. They are also the most difficult part of the suit, she adds. They must be protective, both thermally and physically. They must be fitted enough to allow the astronaut to perform manual labor, but not so tight as to cause compression of nerves and vessels. This example shows several notable design elements: protective finger tips that are still lightweight enough to allow tactile ability; a restraint system composed of loose threads and metal loops to allow the gloves to be precisely sized; and materials to optimize gripping ability. Today, gloves also have built-in heating elements. The quest for the perfect hand-covering continue, and NASA sponsors a glove-design competition every few years.
Landings on the moon meant that helmets needed to allow an expanded range of vision. Astronauts doing construction work on the International Space Station need a full range as well. This fully clear, polycarbonate bubble helmet does the trick. A detergent coating prevents steaming and fogging. The white patch on the back of the helmet distributes air into the helmet with blowing on the astronaut’s neck. On the Space Station today, the bubble is covered by the Extravehicular Visor Assembly. The visor is coated with a thin layer of gold to filter out the sun's rays and offer other protection. A camera and lights can be attached to the helmet.
Alan Eustace's Free-Fall JumpsuitCourtesy of Smithsonian's National Air and Space Museum
This is not a spacesuit, but a stratospheric exploration suit, worn by Alan Eustace in October 2014 during his record-breaking free-fall jump. The 57-year-old Google executive plunged from more than 25 miles above the surface of the Earth, traveling faster than the speed of sound in a harrowing, 14-minute ride. His one-of-a-kind system was developed by Paragon Space Development, United Parachute Technologies, and ILC Dover, the company that has made spacesuits for NASA since the Apollo program. It features a combination of spacesuit technology and off-the-shelf technologies used in skydiving and alpine sports.
This suit is something of a test case on the path to the spacesuit of the future. One breakthrough here is the switch from rubber to thinner, longer-lasting polyurethane for the pressure bladder. There are also helmet updates and new life-support technologies – all of which may serve as precursors to next-generation space missions. Still, certain features developed for the Apollo program, and even Gemini, were still in use, including a liquid cooling garment and thermal micrometeoroid garment, to protect against temperature differences, radiation, and space particles.
PXS and Z-2Courtesy of NASA
Spacesuits are designed to keep humans alive and protect them from extreme temperatures, radiation, and particles. “But in addition to that,” says Lewis, “what the spacesuit has to do is really tied to the mission.” If future human space journeys are to include Mars landings, operation in the asteroid belt, and other forays into deep space, suits will need to meet a slew of new challenges. For one, they will need to operate for a much longer term, which necessitates the development of more durable materials or a replaceable system. Insulation technology allows suits to operate in a range of approximately plus or minus 250 degrees Fahrenheit, but those limits will be tested or exceeded for deeper-space exploration. NASA says it is working on “incorporating advancements such as regenerable carbon-dioxide-removal systems and water-evaporation systems that more efficiently provide crew members with core necessities such as breathing air and temperature regulation.”
NASA’s PXS and Z-2 suits (at left and right) are advanced prototypes and “technology demonstrators.” The PXS, the agency says, “uses a novel approach incorporating sizing features that could one day be 3-D printed on-orbit, in transit, or on Mars to achieve a customized fit for any crew member or change the orientation of bearings to optimize [extravehicular] mobility for different mission phases.”
The futuristic-looking Z-2, NASA says, is designed for “maximum astronaut productivity on a planetary surface – exploring, collecting samples, and maneuvering in and out of habitats and rovers.” It uses “advanced composites to achieve a light-weight, high-durability suit that can withstand long-duration missions in the harsh environments found on Mars.” In NASA’s labs, and in collaboration with MIT, other universities, and private companies, other exotic features are being tested, including such designs as a “biomimicry” cover layer that is inspired by the unique adaptations to extreme conditions exhibited by aquatic creatures on the ocean floor. Time will tell, but perhaps those old comics and pulp magazines were not as far off as we thought...