Spacesuits are undoubtedly life-saving for astronauts as the unprotected human body can only endure the harsh environment of space for a brief moment.
But contrary to popular belief from Sci-Fi films and literature, astronauts don’t suddenly freeze when their space helmets crack. Instead, right away the flesh begins to expand to twice its size and consciousness begins to fade after around 15 seconds as oxygen deprivation begins.
This week, NASA unveiled the first prototype for a next-generation spacesuit tailored for its astronauts on missions to the moon in the next few years.
NASA chief Bill Nelson said the new suits, dubbed the Axiom Extravehicular Mobility Units, “will open opportunities for more people to explore and conduct science on the moon than ever before”.
They are said to be more flexible than the old Apollo designs, have a greater range of motion and incorporate advances in life-support systems, pressure garments and avionics.
The suits are also designed to fit a broad range of potential wearers — at least 90 percent of the American male and female population.
But how are spacesuits designed and in what ways have they changed throughout the ages?
Types of suits and features
Spacesuits are designed to withstand space’s vacuum and extreme temperatures. They are made for missions that take place inside and outside a spacecraft, or for a hybrid of both.
“A spacesuit is much more than a set of clothes astronauts wear on spacewalks. A fully equipped spacesuit is really a one-person spacecraft,” NASA explains.
There are four main conceptual approaches to suit design: soft suits, hard suits, hybrid and skintight.
Soft suits are used mainly inside a pressurised spacecraft, such as the International Space Station (ISS), for intra-vehicular activities (IVA) that are designed to have safety precautions in case of loss of cabin pressure.
Despite the name “soft”, all space suit designs incorporate hard elements, especially at interfaces such as the waist seal, bearings and mostly back hatch.
Still, soft suits are lighter and more comfortable than those used outside the craft for extravehicular activities (EVA).
Hard suits designed for EVA must both protect the wearer against all conditions of space as well as ensure mobility. They are worn in the Earth’s orbit, outside the ISS, on the surface of the Moon and en route back to Earth from the Moon.
Hybrid spacesuits are made in combination to be used for intra/extravehicular activity (IEVA).
Depending on the mission, hard-shell suits are usually made of metal or composite materials and do not use fabric for joints.
Overall, all designs ensure astronauts are able to comfortably bend their limbs inside the suits, which is tricky as garments tend to stiffen against a vacuum.
The suit’s internal pressure can ease mobility as it can be less than the pressure of the Earth’s atmosphere. This is because there is no need for the suit to carry nitrogen gas, which comprises about 78 percent of Earth’s atmosphere but is not used by the body.
With lower pressure inside the suit, greater mobility is ensured. Meanwhile, mobility is achieved by careful joint design.
Suits also have a system to supply oxygen and eliminate carbon dioxide, temperature regulation, a communication system (which is typically provided through a helmet worn over the head), storage of water to drink and a means of collecting bodily waste.
More advanced suits also include protection from ultraviolet radiation and small micrometeoroids and a means to manoeuvre, dock, release and tether onto a craft.
But since the launch of NASA’s first spacesuit to its latest tailored lunar wear, several features have changed and evolved.
From Mercury to EMU
Although the first suit used in space was the Soviet SK-1 worn by Yuri Gagarin in 1961, full-pressure gear for use in extreme altitudes were designed as early as the 1931 when Evgeniy Chertovsky created a full-pressure suit or high-altitude “skafandr”.
The first NASA suit, called the Navy Mark IV, was a high-altitude/vacuum suit created for Project Mercury during 1961 to 1963.
Three suits were created for each astronaut, one for training, one for flight and one backup, all of which had to be customised for their build.
The Mercury suits had no failures during launch, however, an uncapped ventilation inlet valve almost led to the drowning of astronaut Gus Grissom. The hatch cover blew off and began to flood, forcing Grissom to make an emergency exit.
But astronauts complained of discomfort from lack of efficient temperature control and inability to turn their head inside the suit. So the Gemini space suits were created from 1965 to 1966.
They were split into three types: G3C for IVA use, G4C for IEVA use and the G5C suit for the Gemini 7 crew during their 14-day mission inside a spacecraft.
While the Gemini suits were improved from the initial Mercury suits, they did not contain their own life support. Astronauts had to breathe oxygen from the spacecraft through the hose.
So the Apollo Block I A1C suit, a spin-off of the Gemini suit, was created with several differences including a key Portable Life Support System (PLSS) backpack and removable boots to walk on rocky ground.
The nylon pressure suits were created for two early Apollo missions, but were discontinued after they melted and burned in the Apollo 1 cabin fire.
Its nylon outer layer was replaced with a fireproof Beta cloth, a liquid-cooled undergarment and an outer micrometeoroid garment were all added. Thus was born The Block II Apollo.
In total, the Apollo II suits were used in eleven Apollo flights, three Skylab flights and the Apollo–Soyuz Test Project between 1968 and 1975.
After this, the various Shuttle Ejection Escape Suits and the Launch Entry Suit were created and used until 1998 based on models from the United States Air Force.
In addition, the Advanced Crew Escape Suit (ACES suit) was created and worn by all Space Shuttle crews for the ascent and entry parts of flights starting in 1994.
But from 1982 to today, the current suit NASA astronauts wear on the Space Shuttle and ISS is known as the Extravehicular Mobility Unit (EMU). It also allows astronauts to perform an EVA in Earth’s orbit.
It is a 14-layered pressurised suit that can be worn for as long as seven hours in the vacuum of space. Parts of the suit also come in different sizes to match different builds.
Of these 14 layers, three layers make up the liquid cooling garment to prevent overheating, four layers make up the pressure garment and seven layers make up the thermal micrometeoroid garment which protects the astronaut from the sun’s rays and pieces of space dust.
But critics have been saying the suits are long-overdue for a revamp as astronauts reported they were too bulky and need to be improved to work safely on the surface of another planet, such as Mars.
“Today’s bulky spacesuits weigh (or, for pedants, have a mass that is) nearly a third more than those sported by the Apollo astronauts who walked on the Moon in the 1960s and 1970s,” reported the Economist last month.
The more than 40-year-old EMU has had its fair share of accidents such as in 2013 when an Italian astronaut nearly drowned inside it after more than a litre of cooling water flooded his helmet.
Over the years NASA spent hundreds of millions of dollars to upgrade the suits and in 2022, announced Axiom Space and Collins Aerospace would develop the next generation spacesuits.
The new suits will “let astronauts move more freely, making it easier to work. The suits will be more abrasion-resistant, to protect from damage by rough surface dust,” NASA says on its website.