They say the clothes make the man. Perhaps nowhere is that more true than on space missions, where astronauts (both male and female) are at their most iconic when donning a spacesuit. The main job of a spacesuit is to protect its wearer. During spacewalks, it must provide a breathable atmosphere, allow for easy movement and maintain steady communications with a spacecraft. The outfit has to moderate temperature extremes — the sun’s rays can heat an astronaut up to 248 degrees Fahrenheit while the darkness of space can create chills of -256 degrees — and be tough enough to protect against bombardment by dangerous micrometeorites. Like all fashion, the spacesuit is subject to change. Early designs grew out of the pressurized suits worn by trailblazing pilots in hot air balloons and airplanes. Since then, spacesuits have grown into machines of impressive complexity, even becoming miniature spacecraft that fly independently. Spacesuits have allowed people to grab rocks from the lunar surface, make repairs on the Hubble Space Telescope, or float through the void while gazing down at the planet below. Here, Wired Science takes a look at the evolution of this sometimes underappreciated garment. Above: A Russian Orlan model spacesuit soars above the blue Earth. This particular spacesuit was no longer needed and so was filled up with batteries, internal sensors and a radio transmitter and released into a decaying orbit on Feb. 3, 2006. Designated SuitSat, the empty vessel burned up in the atmosphere a few weeks later. Image: NASA

Early Pressure Suits As pilots flew to greater and greater heights during the modern era of flight, people had to don pressure suits to provide oxygen when the air became too thin. Balloonists and, later, airplane pilots were the first innovators of such clothing. One of the earliest pressure suits invented was an 1894 Australian armored outfit made of a wire frame covered with waterproof material. Fred M. Sample patented the first pressure suit in the US on Jul. 16, 1918. It was meant “for supplying air to aviators when making flights at high altitudes or to travelers crossing high mountains.” Fabricated from an elastic material, the invention shares many characteristics with modern spacesuits, including an airtight body suit that completely encloses the wearer, a helmet that can be readily opened and closed during transition from normal atmospheric conditions to thinner atmospheres, and a flexible air-supply hose connected to a source of compressed air and a pump. Image: US Patent Office

Later Pressure Suits American aviator Wiley Post, the first man to fly solo around the world, was a major innovator of pressure suits. In April of 1934, he visited the Los Angeles B.F. Goodrich plant and asked for “a rubber suit, which will enable me to operate and live in an atmosphere of approximately twelve pounds absolute (5,500 feet altitude equivalent).” In his first flight using the pressure suit, Post reached 40,000 feet, setting an altitude record and discovering the jet stream in the process. A later iteration of Post’s pressure suit (left image) was made from latex poured over cotton clothing. It had a metal helmet with a glass visor and attached at the neck using wing nuts. This suit incorporated several layers — long john underwear, an inner rubber air-pressure bladder, and an outer cloth contoured suit — a feature seen in most modern spacesuits. Between 1940 and 1943, several U.S. companies were investigating or producing pressure suits. Looking particularly science-fictiony, many of these featured a transparent, dome-like plastic helmet and airtight rubberized fabric garments that severely restricted a wearer’s range of motion. Engineer Russell Colley developed a major breakthrough with the XH-5 “Tomato Worm Suit” model (right image). The knees, hips, and elbows were made with segmented joints, resembling the body of the tomato hornworm, which provided a flexibility lacking in earlier designs. Images: US Air Force

The First Spacesuit The first spacesuit ever used in space was the Russian SK-1. Designed for Yuri Gagarin flying the maiden voyage of the Vostok 1 spacecraft on Apr. 12, 1961, this suit provided full pressure and an auxiliary life-support system. After reentry, Gagarin had to eject from his spacecraft and parachute down to the ground. He landed in a field, where a farmer and her daughter spotted the strange sight of a man clad in a bright orange suit with a large white helmet. Gagarin later recalled, “When they saw me in my space suit and the parachute dragging alongside as I walked, they started to back away in fear. I told them, don’t be afraid, I am a Soviet like you, who has descended from space and I must find a telephone to call Moscow!” Image: de:Benutzer:HPH/Wikimedia

American Spacesuits When the U.S. entered the space race, NASA realized its Mercury astronauts needed protection from sudden depressurization of their spacecraft’s cabin. Alan Shepard wore the first Mercury spacesuit during his suborbital flight in the spacecraft Freedom 7 on May 5, 1961. These garments grew out of pressure suit designs worn by high-altitude flight test pilots. They had an inner layer of Neoprene-coated nylon and a distinctive aluminized nylon outer layer, originally meant to protect pilots against ultraviolet and thermal radiation. This reflective metal look would become a staple of science fiction films during the 1960s and '70s. Image: NASA. Mercury astronauts: front row, left to right, Walter H. Schirra, Jr., Donald K. Slayton, John H. Glenn, Jr., and Scott Carpenter; back row, Alan B. Shepard, Jr., Virgil I. Gus Grissom, and L. Gordon Cooper.

Spacewalks in Spacesuits In March 1965, the USSR achieved a record when cosmonaut Alexey Leonov stepped outside the Voskhod 2 spacecraft and conducted the first spacewalk. Though Leonov was only out in space for approximately 12 minutes, his Berkut spacesuit had enough oxygen to last 45 minutes. His air supply was strapped to him in a metal backpack with a relief valve that vented away heat, moisture, and carbon dioxide. Due to the suit’s stiffness, Leonov had great difficulty getting back to the ship’s airlock and arrived bathed in sweat from the exertion. There are few high-quality images of the historic walk, but a representation is given in this 1967 USSR stamp (top image). Hot on the heels of this milestone, U.S. astronaut Ed White achieved the first American spacewalk in June 1965 (lower image). After stepping outside the Gemini IV spacecraft, White remained in space for 23 minutes, inside a spacesuit that was designed to provide an hour’s worth of life support. The Gemini suits consisted of six layers of nylon, a full pressure helmet with earphones and a microphone, and gloves detachable by locking rings that allowed easy rotation of the wrist. These spacesuits were meant to provide a fuller range of motion than those used during the Mercury missions. Images: 1) Post of Soviet Union 2) NASA

Spacesuits on the Moon Perhaps the most famous spacesuits are those worn by the Apollo astronauts during their excursions on the moon. Used between 1968 and 1975, these outfits needed to provide greater flexibility and maneuverability than any before, while also being lightweight and comfortable for long jaunts on the lunar surface. They had to protect their wearer from the tough terrain and provide the ability to stoop down and collect rocks. In most of these requirements, the spacesuits were a great success. Neil Armstrong, the first man on the moon, described his suit as “tough, reliable and almost cuddly.” They featured the famous fishbowl helmet, which allowed for wide, unrestricted views, and a three-layer liquid cooling and ventilation garment that circulated cold water to prevent an astronaut from sweating too much and fogging up his faceplate. The initial suits provided six hours of life support but later Apollo missions, such as those using the lunar rover, had improved batteries to last an extra hour. These later garments carried more water and oxygen, and also featured small energy bars in special pouches beneath the outer ring helmet. Similar suits were used through the 1970s on the U.S. space station, Skylab. Though never used, Russian Krechet spacesuits were developed in 1967 for an uncompleted USSR mission to the moon. They have a 10-hour life support capacity and are the first semi-rigid spacesuits ever developed, with a hard aluminum upper torso and soft fabric limbs. One innovation they had was a rear-entrance system (astronauts enter through the backpack), which allowed them to be donned much more easily than Apollo suits. Later U.S. spacesuits incorporated many of the designs from the Krechet. Images: 1) NASA/Neil Armstrong 2) Craigboy/Wikimedia

Modern Spacesuits American astronauts have used the Space Shuttle Extravehicular Mobility Unit since 1982. The EMU is a semi-rigid two-piece suit, consisting of a hard upper torso section with primary life support, electrical systems and Apollo-style bubble helmet and a soft lower piece that covers the astronaut’s waist and legs. The outfit provides life support for 8.5 hours, with 30 minutes of reserves, and requires astronauts to “pre-breathe” for 45 minutes to adjust for the 100 percent oxygen environment that fills the suit. Before an astronaut slips on the EMU, they don a Maximum Absorbency Garment, a NASA euphemism for what is essentially a “Depends” diaper (made famous during the case of Capt. Lisa Marie Nowak, who wore them on a 900-mile journey from Houston to Orlando intending to cause serious bodily harm to another crewmember that was her rival in affection for a third astronaut). The Russian Orlan spacesuits (first image below) have been used since the late 1970s for missions to Mir and the International Space Station. They feature a rear-hatch entry, allowing them to be donned in approximately five minutes, and can operate for nine hours before needing a resupply. Chinese space missions make use of the Feitian spacesuit (second image below), which is modeled after the Russian Orlan suit. Taikonaut Zhai Zhigang wore one on the first Chinese extravehicular activity in 2008 during the Shenzhou 7 mission.

Images: 1) NASA 2) NASA 3) Johnson Lau/Wikimedia

Untethered Spacesuit In 1984, NASA tested the Manned Maneuvering Unit, a jetpack-like device that was the first to fly under its own power completely separate from a spacecraft. Employed on three missions, it was utilized to repair several satellites. The backpack is designed for wear over a standard Extravehicular Mobility Unit. It has 24 thrusters at various positions that expel nitrogen, allowing an astronaut to fly with precision around the Space Shuttle cargo bay or to nearby payloads and structures. After the 1986 Challenger disaster, use of the manned maneuvering unit was discontinued on safety grounds. Image: NASA

Future Spacesuits NASA is currently developing its next-generation spacesuits, intended for journeys to an asteroid, Mars, or back to the moon. The Mark III spacesuit (left image) is a rear-entry suit like the Russian Orlan suit, with a hard upper torso made from graphite/epoxy composite elements and soft fabric joints at the knees and elbows. It is lighter and more maneuverable than the current Extravehicular Mobility Unit and provides a more Earth-like atmospheric composition so that astronauts do not have to adjust once inside the suit. Alternatively, the I-Suit (right image) is an all-soft suit that uses lightweight titanium to achieve a total weight slightly more than half of current spacesuits. Both suits have been in testing since 2004. Images: NASA