PlayInfoBox

Home /Education /How Spacesuits Work

How Spacesuits Work

Click on an entry to see the details.

1. The principle behind maintaining pressure

Outer space is nearly a vacuum, and being exposed without protection could cause bodily fluids to boil. A spacesuit protects the body from vacuum by maintaining an internal pressure similar to Earth's atmospheric pressure.

2. Multi-layer structure

A spacesuit is made by layering several special materials β€” a cooling garment, a pressure layer that maintains an airtight seal, an insulating layer, and an outer layer that blocks micrometeoroids and ultraviolet light β€” combining multiple functions into one suit.

3. Protection from extreme temperature differences

In space, surfaces directly exposed to sunlight can reach about 120Β°C, while shaded areas can drop below βˆ’100Β°C; the spacesuit's insulating layer maintains body temperature even amid these extreme temperature swings.

4. Liquid cooling garment

Inside the spacesuit, astronauts wear a liquid cooling garment that circulates water through thin tubes, efficiently cooling the body heat generated during activity.

5. Life support system (PLSS)

A backpack-style life support system supplies oxygen and removes carbon dioxide and moisture produced by breathing, and also has communication equipment built in.

6. Spacesuits for extravehicular activity (EVA)

On the ISS, spacesuits such as the US EMU and Russia's Orlan are used, each equipped with its own independent life support system, allowing astronauts to operate separately from the main spacecraft during extravehicular activity.

7. Launch and reentry suits

Like the pressure suit worn by SpaceX Crew Dragon astronauts, the suit worn during launch and reentry is designed to be lighter and thinner than an EVA suit, intended for emergency situations such as cabin depressurization.

8. Helmet and visor

The helmet is fitted with a thin gold-coated sun visor to protect the eyes from ultraviolet light and intense sunlight, significantly reducing glare.

A spacesuit is like a small spacecraft

A spacesuit is not simply clothing β€” it is an independent life support system that handles pressure maintenance, temperature regulation, and oxygen supply all on its own. This is why astronauts sometimes call a spacesuit a "spacecraft you wear."

How spacesuits are used on the ISS

Spacesuits play a particularly important role in extravehicular activity for ISS maintenance. See our overview of the International Space Station (ISS) to explore how spacewalks are carried out.

Frequently Asked Questions

Is it really dangerous to be exposed to space without a spacesuit?

Yes. In the vacuum of space, the absence of atmospheric pressure can cause bodily fluids to boil, and oxygen deprivation can cause loss of consciousness very quickly β€” without a spacesuit, it's difficult to survive safely for even a few seconds.

Isn't it hot inside a spacesuit?

Body heat is generated during high levels of activity, but the liquid cooling garment built into the spacesuit circulates water to effectively lower body temperature, keeping the wearer comfortable.