What do astronauts wear in space?

A space suit, often known as a spacesuit, is a garment worn by astronauts to keep them alive in the harsh environment of outer space, vacuum, and temperature extremes. Space suits are frequently worn within spacecraft as a safety measure in the event of cabin pressure loss, and they are required for extravehicular activity (EVA), or work performed outside of spacecraft. Space suits have been worn for such tasks in Earth orbit, on the Moon's surface, and on the way back to Earth from the Moon. Modern space suits supplement the basic pressure garment with a complex system of equipment and environmental systems designed to keep the wearer comfortable and to minimize the effort required to bend the limbs, thereby resisting the natural tendency of a soft pressure garment to stiffen against the vacuum.

To provide total freedom of movement independent of the spaceship, a self-contained oxygen supply and environmental control system is typically used. There are three varieties of space suits: IVA (intravehicular activity), EVA (extravehicular activity), and IEVA (intra/extravehicular activity). Individual innovators created the first full-pressure suits for usage at severe altitudes as early as the 1930s. The Soviet SK-1 suit, worn by Yuri Gagarin in 1961, was the first space suit worn by a human in space.