The technologies we rely on to make space exploration possible are constantly evolving. One of the most important, though easily overlooked, technologies necessary for space exploration is the humble spacesuit.
Without specialized suits to keep astronauts safe, major events like the moon landing and the first space walk simply wouldn't have been possible. Here's a quick look at how far we've come from the earliest pre-cursors to spacesuits, to the exciting new developments of today.
The Litton Mark I: One of the First Spacesuits
While working for Littion Industries in the early 1950s, Dr. Siegfried Hansen unknowingly laid the groundwork for future generations of space suits. Hansen created the Mark I, a suit designed to be worn within a vacuum.
The Mark I might seem primitive by today's standards, but it was the first suit to allow its wearer to breathe within a vacuum and still offered a good deal of mobility.
Though vacuum tubes became obsolete thanks to transitor technology, the Mark I didn't become a relic. Instead, researchers who were working on sending the first humans to space recognized the usefulness of the suit.
Today, the Mark I is widely considered as the first extravehicular activity suit.
The Mercury Suit: The First American Spacesuit
Developed by the B.F. Goodrich Company in the late 1950s, the Mercury Suit (also known as the Navy Mark IV) was a modified pressure suit, based on designs used by the United States Navy. The suits were originally designed by Russell Colley for use during the Korean War.
NASA's Mercury Project kicked into gear in 1959, and the need for a spacesuit to protect astronauts quickly became apparent.
NASA scientists noted Mark IV as a potential model, given its ability to protect pilots at high altitudes and maintain an atmosphere similar to that of Earth's.
To make the design viable for space, they coated the suit with aluminum for thermal control, and added a closed loop breathing system which pumped oxygen into the suit through a tube at the waist.
The SK-1: The First Spacesuit Used in Space
The Russian-made SK-1 has the distint honor of being the suit worn by the first man in space, Yuri Gagarin. In fact, the breakthrough suit was designed especially with Gagarin in mind. The suit was in use from 1961 until 1963, and was worn by cosmonauts on other Vostock missions.
As the Vostock had no soft landing system, the suit was designed with an ejection function that would allow cosmonauts to safely eject themselves from the craft before landing. It allowed ejections of up to 26,000 feet (8 km) and came equipped with a life support system.
The Gemini Space Suits: Developing Suits For Different Uses
In the early days of space suit development, it gradually became apparent that different suits were needed for different environments and uses. The Gemini series of spacesuits, built throughout the mid-1960s, sought to address these differences by creating specialized suits for every eventuality.
These included the G3C, which was created for intra-vehicle use and was worn on the Gemini 3.
Another Gemini suit was the G4C, which could be used as both an intra-vehicle and extra-vehicle suit, and was worn during the first American space walk in 1965. The Gemini suits would later be modified for the Apollo missions.
The Apollo/Skylab A7L: The Suit That Landed On the Moon
To make the dream of a man walking on the moon a reality, NASA had to create a suit that not only kept their astronauts alive in the vacuum of space, but which would also allow for moonwalking. The design would have to protect its wearer from the effects of radiation, as well as depressurization.
With these concerns in mind, NASA developed what they referred to as EMUs - extravehicular mobility units, which has become colloquially known as the Apollo or Skylab suit.
The suit featured a water-cooled undergarment that was fit with 300 feet (91 meters) of tubing. An additional "backpack" containing oxygen and cooling water was also worn for walking on the moon's surface.
The Berkut: Worn During the First Ever Space Walk
Modified from an SK-1 suit, the Berkut was an extravehicular activity (EVA) suit worn by Alexy Leonov during the first space walk. The suit contained enough oxygen for 45 minutes of activity, and was only used during the Voskhod 2 mission, due in part to its poor mobility.
The space walk itself revealed weaknesses in the suit's design that would later help the Soviets to improve their technology. For starters, Leonov's body temperature rose dramatically during the space walk, putting him in danger of heatstroke.
The stiffness of the suit also made Leonov's re-entry of the Voskhod 2 a difficult and complicated affair, and the structural integrity of the suit was compromised. Luckily, Leonov kept his cool and returned to the safety of the ship, but the first space walk nearly had a very different ending.
The Shenzhou IVA: Worn On the First Manned Chinese Space Flight
The suits worn on the first manned space flight from China were reverse-engineered from Russian SK-1 suits. Russia sold the suits to China in 1992, where they were taken apart and rebuilt for the Shenzhou program.
As an intra-vehicle suit, the Shenzhou suit has no temperature or pressure controls. It was worn for the duration of the day-long Shenzhou 5 mission, which launched in October 2003 and saw Yang Liwei become the first Chinese man in space.
The Sokol: Worn From 1973 to Today
The Sokol is a strictly intra-vehicle activity (IVA) suit, worn in case of depressurization aboard Russian spacecraft. It was created in response to the deaths of the crew aboard Soyuz 11 in 1971, who died during re-entry due to depressurization. First developed in 1973, the suits are still worn on missions today.
The improvements featured in the Sokol include an open-circuit life-support system, and a pressure relief valve which regulates the suit's internal pressure. The suit is a modification of an aviation suit, as opposed to a pre-existing spacesuit. Once suited, the wearer can survive for up to 30 hours in a pressurized cabin and up to 2 hours in an unpressurized atmosphere.
The Extravehicular Mobility Unit: Used Aboard the International Space Station
NASA's Extravehicular Mobility Unit (EMU) was first introduced in 1981, and is still used today aboard the ISS. The suit supports wearers for up to 7 hours outside of the craft, and is made up of 14 separate layers.
The first layer is a cooling undergarment which, like earlier models, uses a cooling liquid to protect the astronaut from over-heating. It also includes a layer to maintain air pressure inside the suit, and a thermal micrometeroid layer to protect the wearer from the sun's rays and small pieces of space debris.
The Orlan: From Soviet Space Stations to the ISS
Developed in the late 1970s, the Orlan has been worn aboard the Soviet space station, Salyut 6, and is today still used aboard the ISS. In 2003, an Orlan suit was fitted with a radio transmitter and launched into orbit, effectively becoming the first spacesuit satellite named SuitSat-1.
Though the SuitSat-1's mission was a short-lived one, lasting just two orbits before its batteries died and transmissions ceased, it was fitted with a CD of art collected from across the globe. In 2006 the suit burned up in the Earth's atmosphere, just above the Southern Ocean.
The Feitian: China's First Indigenous Spacesuit
Revealed in 2008, the Feitian was the first Chinese spacesuit built and designed entirely in China. An EVA, it was worn by Zhai Zhigang during China's first space walk in September 2008.
The suit took four years to develop, and is modeled on Russia's Orlan suit. Like the Orlan, it can support extravehicular activities of up to 7 hours. Its name directly translates as "flying in the sky", and also the name of a Buddhist goddess.
The Final Frontier Design IVA Space Suit: A Suit Built by a Start-Up
Founded in 2010 by artist Ted Southern, Final Frontier Design caught the public's attention for being a start-up dedicated to designing and creating cutting-edge spacesuits. Usually the domain of government-funded scientists, Final Frontier Design showed the world that with the right know-how, anybody could enter the business of spacesuit design.
Southern and his co-founder, engineer Nikolay Moiseev, won second-place in a NASA competition in 2009, which inspired them to find their own space technology start-up.
In 2014, they received a Space Act Agreement from NASA and at present they're working on their fourth-generation spacesuit. Meaning that in the near future, astronauts could be wearing suits designed by engineers working outside the traditional confines of the space industry.
The SpaceX Space Suit: Driving Through Space At This Very Moment
Earlier this year, SpaceX launched their "Starman" - a mannequin wearing the company's spacesuit, sitting behind the wheel of a Tesla roadster. It was a compelling image, but not a great deal is known about SpaceX's suit or how it will hold up in space.
Elon Musk has assured the press that the suit is safe to wear in vacuum chambers. The sleek design is intended for intra-vehicle activities only, specifically for use within the Dragon - SpaceX's transport capsule for ferrying passengers and cargo to the ISS.
The Z Series: NASA's New Generation of Suits
Though it might look like something Buzz Lightyear would wear, the Z-series suits are actually part of a new generation of suits created by NASA's Advanced Exploration Systems program. The Z-2 is designed for use on other planets, while its precursor the Z-1 was a softer-bodied suit ttrialed on the ISS last year.
NASA hopes the Z-2 will be used on the first manned Mars landings, and have designed the suit to be as lightweight and mobile as possible to aid in the collection of data.
The Aouda.X: Preparing For A Mars Landing
Another set of innovators with their sightes set on the red planet is the Austrian Space Forum. They've created the Aouda.X - a spacesuit simulator that can prepare astronauts for exploring the surface of other planets.
The helmet has a head-up display, and the suit includes sensors and software that can interact with pre-existing tech on Mars, like rovers. Though the suit in its current form is not suitable for use in space or on other planets, it allows astronauts to get a feel for what they can expect on foreign surfaces.