Spacesuit

A spacesuit is a complex system of garments, equipment, and environmental systems designed to keep a person alive and comfortable in the harsh environment of outer space. This applies to extra-vehicular activity outside spacecraft orbiting Earth and has applied to walking, and riding the Lunar Rover, on the Moon.

It has to provide pressure (like the air pressure on Earth), oxygen and temperature regulation (in fact cooling).

There are three theoretical approaches:

• Hard shell suits have constant volumes, and motion is therefore very easy, because the pressure inside the suit does not oppose motion. Instead of air conditioning, most hard suits use a cool-suit with soft tubes carrying cold water.
• Skin suits use a heavy body stocking to compress the body. Most proposals use the body's natural sweat to keep cool. No one knows how to put one on.
• Flexible pressure suits are the kind most in use. They combine all the bad features: heavy weight, the need for a cool suit, and difficult motion because the suit wants to blow up like a balloon. Their one saving grace is that they do not limit the range of motion.

Related preceding technologies include the gas mask used in WWII, the oxygen mask used by pilots of high flying bombers in WWII, the high altitude or vacuum suit required by pilots of the Lockheed U-2 and SR-71 Blackbird, the diving suit, scuba diving gear and many others. It is a very complicated task to provide an Earthlike comfortable environment to people traveling and working in harsh alien environments such as orbit or the lunar surface.

Specific suit models of historical significance.

• Russian suit models
  • Yuri Gagarin, First Man in Space Orbits Earth
  • the Orlan suits for Extra-vehicular activity
  • the Sokol suits worn by Soyuz crew members during lift-off and re-entry
• Mercury High Altitude/Vacuum Suit
• Gemini Spacewalk suits
• Apollo Lunar Surface Suits
• Skylab
• Space Shuttle
• Emerging Technologies
  • Hard Shell

See also manned maneuvering unit.