Working outside
What Is a Spacewalk Like?
No air, no warmth, no up. Just you, a suit, and a tether.
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Step 1 of 5
Space is not just cold — it is empty.
There is no air at all. Without a suit you would have about 15 seconds of useful consciousness, and the water in your body would start to boil.
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Step 2 of 5
The suit is a balloon holding you together.
It is pumped up with oxygen at about a third of sea-level pressure. That pressure is what keeps your blood liquid and your lungs working.
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Step 3 of 5
Temperature swings 250 degrees.
In sunlight the outside of the suit hits 120°C. In Earth's shadow it drops to −150°C. The suit does the heating and cooling for you.
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Step 4 of 5
Turning a bolt turns you instead.
With nothing to brace against, every push you make pushes you back. Astronauts spend most of a spacewalk holding on with one hand and working with the other.
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Step 5 of 5
The tether is everything.
You are always clipped on. Suits also carry a small jetpack for emergencies, but no astronaut has ever needed it — nobody has drifted away.
A spacewalk lasts six to eight hours, and astronauts train for each one underwater for about 50 hours.
The short version
A spacewalk means wearing a personal spacecraft, because space itself offers nothing at all.
Try it yourself
Sit on a swivel chair and try to turn a stiff jar lid. You spin instead of the lid. That is spacewalking.
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