When Neil Armstrong and Buzz Aldrin stepped onto the lunar surface in July 1969, they were wearing much more than just a space-age fashion statement. Their iconic white spacesuits represented years of research, testing, and innovation to create a garment that could keep a human alive in the most inhospitable environment imaginable.
From the earliest pressure suits worn by high-altitude pilots in the 1930s to the cutting-edge designs now in development for missions to Mars, the spacesuit has evolved in lockstep with our ambitions to explore the cosmos. It serves as a personalized life support system, radiation shield, thermoregulator, and even a communications array—all while providing the flexibility and dexterity to perform complex tasks.
"A spacesuit is really a miniature spacecraft shaped like a human being," explains Dr. Cathleen Lewis, curator of international space programs and spacesuits at the Smithsonian‘s National Air and Space Museum. "Every aspect of its design involves tradeoffs between competing requirements for protection, mobility, and comfort."
Suiting Up for the Space Race
The first spacesuit worn by an American in space was little more than a modified version of the Navy Mark IV high-altitude pressure suit. For Project Mercury, which ran from 1958 to 1963, NASA added layers of aluminized nylon and neoprene-coated nylon to better insulate the suits. While adequate for the relatively short, single-person spaceflights of the Mercury program, these suits lacked flexibility and could not dissipate body heat effectively.
| Spacesuit | Program | Key Features |
|---|---|---|
| Navy Mark IV | Mercury | Aluminized nylon outer layer, neoprene-coated nylon liner, dual zippers |
| Gemini G3C/G4C | Gemini | Improved mobility, detachable gloves, liquid cooling garment, emergency oxygen supply |
| A7L | Apollo | Pressure-layer with bellows joints, liquid cooling garment, portable life support system, moon boots |
| Shuttle EMU | Space Shuttle | Hard upper torso, modular components, improved gloves, LCD checklists, in-suit drink bag |
| Orlan | Soviet/Russian | Rear-entry design, polyurethane pressure layer, Krechet-94 portable life support system |
The introduction of spacewalks during the Gemini program from 1965-66 brought new challenges. Ed White became the first American to walk in space in June 1965, but overheating caused his faceplate to fog up, forcing an early end to the EVA. Subsequent Gemini missions incorporated liquid cooling garments and improved ventilation.
It was the Apollo program that saw the first major leap in spacesuit technology. To explore the surface of the Moon, astronauts needed a suit that could withstand temperatures ranging from +250°F to -250°F, provide enough flexibility to walk and work on the lunar surface, and incorporate a life support system to supply oxygen and scrub exhaled carbon dioxide for up to 7 hours. The resulting A7L suit featured a multi-layer pressure garment, convoluted joints for mobility, a portable life support backpack, and a liquid cooling garment that circulated chilled water through a network of tubes.
Over the course of six lunar landing missions, the Apollo spacesuits enabled a total of 14 astronauts to spend over 80 hours exploring the Moon‘s surface. The final EVA of Apollo 17 in December 1972 lasted a record 7 hours and 37 minutes. But the suits were heavy (weighing over 200 lbs on Earth), difficult to move in, and could be donned only with assistance.
For the Space Shuttle program, NASA introduced the Extravehicular Mobility Unit (EMU), which remains in use on the International Space Station today. The EMU features a hard upper torso, modular components that can be mixed and matched for different-sized astronauts, and improved gloves with fingertip heaters. It also includes an in-suit drink bag and LCD cuff checklists. A separate launch-and-entry suit incorporated emergency parachutes and survival gear in case of a bailout during liftoff or landing.
From Low Earth Orbit to Lunar Outposts
Since the first spacewalk by Soviet cosmonaut Alexei Leonov in March 1965, astronauts and cosmonauts have logged over 2,500 hours working in the vacuum of space. The majority of those EVAs have serviced the International Space Station and the Hubble Space Telescope using either the American EMU or Russian Orlan suits.
| Mission | Suit | EVA Time (h:mm) | Notes |
|---|---|---|---|
| Gemini 4 | G4C | 0:36 | First American spacewalk |
| Apollo 11 | A7L | 2:31 | First moonwalk |
| STS-6 | EMU | 4:17 | First Shuttle spacewalk |
| STS-61 | EMU | 35:28 | Hubble repair mission |
| STS-82 | EMU | 33:11 | Hubble servicing mission |
| ISS Exp 1 | Orlan-M | 5:57 | First ISS assembly spacewalk |
| ISS Exp 54 | EMU | 8:13 | Longest single ISS spacewalk to date |
But as NASA looks ahead to sending astronauts back to the Moon and eventually on to Mars, engineers are rethinking spacesuit design from the ground up. The Artemis program, set to return humans to the lunar surface by 2024, will require suits that can withstand the abrasive lunar dust, provide greater radiation protection, and enable longer-duration exploration in both microgravity and on the surface.
One key innovation is the rear-entry hatch, which allows an astronaut to climb into the suit from the back like donning a jacket. This eliminates the need for a separate airlock and makes it easier to work in the confined spaces of a spacecraft or rover. The suit‘s portable life support system will also be more robust, capable of keeping an astronaut alive for up to 8 hours.
For Mars, where temperatures can drop to -200°F and the thin atmosphere provides little protection against solar radiation, suits will need additional layers of insulation and shielding. One promising technology is mechanical counter-pressure, which uses tight-fitting elastic garments to simulate the pressure of Earth‘s atmosphere on the body. This could dramatically reduce the bulk and complexity of future Martian suits.
Other cutting-edge technologies like 3D printing, soft robotics, and augmented reality displays could further enhance the functionality and comfort of spacesuits. But the fundamental challenge remains the same as it was in the early days of the space race: to provide a safe, reliable, and efficient means for humans to survive and work in an environment that is utterly hostile to life as we know it.
"The spacesuit is a triumph of human ingenuity and engineering," reflects Dr. Lewis. "It‘s a testament to our drive to explore, to push the boundaries of what‘s possible, and to extend our reach beyond the confines of our home planet."
As we stand on the cusp of a new era of space exploration, the humble spacesuit will continue to evolve, pushing the limits of technology and fashion alike. But its core purpose remains unchanged: to enable us to take that next giant leap for mankind, wherever it may lead.
Sources
- De Monchaux, Nicholas. "Spacesuit: Fashioning Apollo." MIT Press, 2011.
- Hollingham, Richard. "The design challenges behind the International Space Station‘s new spacesuits." BBC Future. 23 Jan 2020. https://www.bbc.com/future/article/20200123-the-complex-new-design-of-spacesuits
- Jenkins, Dennis R. "Dressing for Altitude: U.S. Aviation Pressure Suits–Wiley Post to Space Shuttle." NASA SP-2011-595. 2012. https://www.nasa.gov/pdf/683215main_DressingAltitude-ebook.pdf
- Lewis, Cathleen et al. "Spacesuits and Spacewalks." NASA History Division. https://history.nasa.gov/spacesuits.pdf
- Oberg, James E. and Alcestis R. Oberg. "Pioneering Space: Living on the Next Frontier." McGraw-Hill, 1986.
- Thomas, Kenneth S. and Harold J. McMann. "U.S. Spacesuits." Springer, 2011.
