Benefits of a Spacesuit
Spacesuits are created in such a manner that they are able to create an Earth-like environment within the suit itself and also allow humans to walk around in space in some amount of safety. Spacesuits are made way to provide the following to the astronauts:
The spacesuit provides air pressure to keep the fluids in the body in a liquid state, preventing body fluids from boiling.
Most spacesuits provide a pure oxygen atmosphere for breathing as it is not possible to use normal air which consists of 78% nitrogen, 21% oxygen and 1% other gases, as low pressures could cause low oxygen concentrations in the lungs and blood. Spacesuits get the oxygen either from a spacecraft through an umbilical cord or from a backpack life support system that the astronaut wears.
Excess carbon dioxide must be removed from the spacesuit's atmosphere as concentration of carbon dioxide could increase lethal levels, in the limited space of the space suit. Spacesuits use lithium hydroxide canisters to eliminate carbon dioxide, and are accessed through an umbilical cord.
Most spacesuits are insulated with layers of fabric (Neoprene, Gore-Tex, Dacron) to survive the extremes of temperature and covered with reflective outer layers (Mylar or white fabric) to reflect sunlight. While performing strenuous activities, immense heat is produced from the astronaut's body. It is essential to eliminate this heat, as the sweat produced would fog up the helmet and make the astronaut dehydrated. For removal of this heat, spacesuits either use fans/heat exchangers to blow cool air, or water-cooled garments.
Spacesuits have several layers of durable fabrics such as Dacron or Kevlar for protection from collisions with micrometeoroids. These layers also prevent the suit from tearing on exposed surfaces of the spacecraft or a planet or moon.
Spacesuits provide restricted protection from radiation. The reflective coatings of Mylar built into the suits offer some protection, but cannot offer much protection from a solar flare. For this reason space walks are planned during periods of low solar activity.
Spacesuits have helmets made from clear plastic or durable polycarbonate. Most helmets have coverings to reflect sunlight, and tinted visors to reduce glare. Further, before a space walk, the internal faceplates of the helmet are sprayed with an anti-fog compound. However, modern spacesuit helmet coverings have mounted lights so that the astronauts can see into the shadows.
Mobility Within the Spacesuit
Movement inside an inflated spacesuit is difficult. To solve this problem, spacesuits are equipped with special joints or tapers in the fabric to help the astronauts bend their hands, arms, legs, knees and ankles.
Spacesuits are facilitated with radio transmitters/receivers to enable space walking astronauts to talk with ground controllers and/or other astronauts. The astronauts wear headsets with microphones and earphones. The transmitters/receivers are located in the chest packs/backpacks worn by the astronauts.
Mobility in the Spacecraft
Movement in weightlessness is difficult. Therefore, spacecraft are equipped with footholds and hand restraints to help astronauts work in micro gravity.
Now as we know the need of spacesuit, let us see the different parts of spacesuit which satisfy these needs.