From Mercury to Artemis: The Incredible Evolution of Spacesuits

1The Mercury Suit: Adapted from Navy Pressure Suits

When NASA needed spacesuits for the Mercury program in the early 1960s, they turned to the B.F. Goodrich company, which had been making pressure suits for Navy pilots. The Mercury suit was essentially a modified high-altitude flight suit made of an inner layer of neoprene-coated nylon for pressure retention and an outer layer of aluminized nylon for heat protection — giving it the iconic silver appearance. The suit was designed primarily as a backup in case the spacecraft cabin lost pressure; astronauts were not expected to leave their capsules. It weighed about 10 kilograms and was custom-fitted to each astronaut. The suit could maintain pressure and provide oxygen but had very limited mobility — astronauts could barely move their arms and legs while pressurized. Despite its limitations, the Mercury suit proved that humans could survive in space with the right protection, paving the way for more advanced designs that would allow astronauts to actually work outside their spacecraft.

• Based on Navy Mark IV high-altitude pressure suit
• Made by B.F. Goodrich (now part of Goodrich Corporation)
• Weight: About 10 kg (22 lbs)
• Silver aluminized nylon outer layer for thermal protection
• Custom-fitted to each of the seven Mercury astronauts

2Apollo Suits: Walking on the Moon

The Apollo program required a completely new kind of spacesuit — one that could protect astronauts not just in the vacuum of space but on the surface of the Moon, where temperatures swing from 127 degrees Celsius in sunlight to minus 173 degrees in shadow. The Apollo A7L suit, made by ILC Dover, was a masterpiece of engineering with 21 layers of material, each serving a specific purpose: inner layers for comfort and cooling, middle layers for pressure retention, and outer layers for micrometeorite protection and thermal insulation. The suit included a liquid cooling garment with tubes carrying chilled water against the astronaut's skin, a portable life support system backpack providing oxygen and removing carbon dioxide, and a gold-visored helmet that protected against solar radiation. The entire ensemble weighed about 82 kilograms on Earth but only 14 kilograms in the Moon's weaker gravity. Despite its bulk, the suit allowed astronauts to walk, bend, pick up rocks, use tools, and even drive the lunar rover during later Apollo missions.

3The Shuttle and ISS Era: EMU Spacesuits

For the Space Shuttle and International Space Station programs, NASA developed the Extravehicular Mobility Unit, or EMU — the white spacesuit most people picture when they think of spacewalks. Unlike the custom-fitted Apollo suits, the EMU was designed with modular, interchangeable parts in different sizes so multiple astronauts could use the same suit components. The upper torso is a rigid fiberglass shell, while the lower torso, arms, and gloves are flexible fabric assemblies. The EMU weighs about 127 kilograms and provides up to 8.5 hours of life support for spacewalks. It maintains a pressure of 4.3 psi (about one-third of sea-level atmospheric pressure) using pure oxygen. Before a spacewalk, astronauts must "pre-breathe" pure oxygen for several hours to purge nitrogen from their blood and prevent decompression sickness — similar to what deep-sea divers must do. The EMU has been used for over 250 spacewalks since 1983, but many of the suits currently in use are over 40 years old and showing their age, with occasional water leaks and other issues.

• EMU: Extravehicular Mobility Unit — used since 1983
• Weight: 127 kg (280 lbs) — but weightless in orbit!
• Provides up to 8.5 hours of life support per spacewalk
• Modular design: Mix-and-match sizes instead of custom fitting
• Over 250 spacewalks completed using EMU suits
• Some suits still in use are over 40 years old

4Artemis xEMU and the Future of Spacesuits

For the Artemis program's return to the Moon, NASA partnered with Axiom Space to develop the Axiom Extravehicular Mobility Unit, or AxEMU. This next-generation suit addresses many limitations of older designs: it offers far greater mobility, especially in the lower body for walking on the lunar surface; it fits a much wider range of body sizes (from the 1st to 99th percentile of the American population); and it includes modern features like HD cameras, LED helmet lights, and improved dust protection. The suit's outer layer is a sleek dark design by Prada, though the final flight version will be white for thermal protection. Meanwhile, SpaceX has developed its own sleek, form-fitting suits for Crew Dragon missions, and their EVA suit debuted during the Polaris Dawn mission in 2024 — the first commercial spacewalk in history. Looking further ahead, researchers are developing "mechanical counter-pressure" suits that use tight, elastic materials to provide pressure against the body instead of inflating like a balloon, potentially making future spacesuits as flexible as athletic wear.