When the United States and the Soviet Union first decided to venture into the cosmos in the mid-20th century, it was readily apparent W that they would need something to protect their explorers from the harshness of space. While pressure suits had been used before on high-altitude jets, no one was quite sure how the human body would cope with weightlessness, and particularly with the vacuum of space if a spacewalk was to be attempted.
One thing that was known for certain, however, was that exposure to space without a spacesuit would be fatal. 20 kilometres (12 miles) above Earth the atmosphere becomes so thin, and the atmospheric pressure is so low, that the water and blood in a human body will start to boil. Above this point, known as the Armstrong limit, some sort of protection is vital. Therefore the idea of a wearable spacecraft designed to protect its occupant from the harshness of space – now known as a spacesuit – was born.
Spacesuits come in a variety of shapes, sizes and uses. In the modern day on the International Space Station (ISS), astronauts wear flight suits for launch and re-entry that are largely designed to protect the occupant in case of a bailout. During a spacewalk they wear a much more sophisticated suit that allows them
