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Space suits are some of the most complicated and unique pieces of technology in the world today. They essentially function as miniaturized personal aircraft providing astronauts with the protection they need to survive in space. Due to the sheer complexity of surviving in space there are many components and materials that go into the design of a space suit.
Layers of the Extravehicular Mobility Unit (EMU)
The modern space suit is composed of 14 different layers of material which all contribute in their own way to the survival of the astronaut.
The Liquid Cooling Ventilation Garment
The three innermost layers make up the liquid cooling ventilation garment. This garment is created from a thin spandex layer that stays snug to the body. This garment is designed to help cool the astronauts and it does this through the use of about 300 feet of tubes which serve to carry cool water over the surface of the spandex thus liquid cooling the astronaut.
This water comes from either the astronaut’s backpack or an umbilical cord leading to the spacecraft as well as recycled water from the sweat of the astronaut and from the water vapor in the carbon dioxide the astronaut is exhaling.
The Bladder Layer
Above this layer is the bladder layer, which is arguably the most essential to the astronaut’s survival. The bladder layer serves to maintain the proper pressure dynamic to protect the astronaut and it does this by containing the same oxygen that the astronaut will breathe inside of the bladder layer’s confined space.
The purpose of the layer immediately above the bladder layer is still directly tied to the importance of the bladder layer, as this layer ensures that the bladder layer retains the proper form for the astronaut. This layer is also made from the same material you might find in a tent where it assists in maintaining the shape of your tent rather than the bladder layer of a spacesuit.
The Ripstop Layer
The next layer is specifically designed to resist any tears that might occur as any direct exposure to space is incredibly dangerous. This layer is aptly referred to as the ripstop layer.
Layers of Mylar Insulation
After the ripstop layer there are seven layers of mylar insulation, a material used often in food storage. This mylar insulation helps to stabilize the temperature of the astronaut much like a thermos or a cooler would stabilize the temperature of your food.
The Final Layers of a Space Suit
The final layer is composed of three fabrics that each serve their own purpose. Kevlar, the material used to create bullet proof vests, makes up one of the layers and serves as a general purpose protective layer. The other two layers are interesting because they serve nearly exact opposite purposes as one is waterproof and the other is fire-resistant.
Overcoming Obstacles in Space
Almost every aspect of space proves to be an obstacle that the space suit must overcome and as such many parts of the space suit are even more specialized than the layers mentioned above.
The visor assembly for example contains gold in order to help filter the intense sunlight that exists in space without the earth’s atmosphere for protection.
This visor assembly also contains a clear impact resistant cover that works in tandem with the helmet for additional thermal protection and protection from impacts that might occur with small space debris.
Even such a small obstacle as the fogging of the inside of the helmet requires a unique antifogging chemical compound to be sprayed before every spacewalk.
The lack of gravity in space presents the risk of losing tools or parts during a spacewalk and as such the spacesuit’s fingertips are covered with a rubberized material to help the astronaut keep their grip.
The extreme cold of space and the sensitivity of extremities to the elements requires the space suit gloves to have miniature heaters in their fingertips. All of these parts, although necessary for the spacesuit’s functionality, work against the suit by adding weight and bulkiness to the suit eventually making it weigh in at around 130 kilograms.
Using Glass Fiber
How do you make a material sturdy enough to keep all of these parts together? The answer is by using glass fiber.
Glass fiber is actually made from glass, just like the glass you might see in a window or a glass bowl, but is made by pouring molten glass through an extremely small hole to create a fiber rather than the glass blowing you might see for other products.
This extremely thin glass fiber is then woven together and combined with a resin in order to give it a hard yet light resilient shape. The glass fiber above is then used to create a number of different products ranging anywhere from boats to aircrafts.
In this case however it is used to create a hard upper torso section of the space suit which is strong enough to support the spacesuit’s helmet, life support backpack, control module, arms and legs.
Future Space Suit Materials
Researchers are constantly looking for new materials to build the space suits of the future and we may not be too far from a complete redesign of the modern space suit. Studies into shape memory alloy coils being conducted by MIT researchers are showing incredible results.
The MIT BioSuit™ - Image Credit: MIT
Shape memory alloy coils are essentially springs that return to their original unstretched shape when they are heated. The pressure created by using these shape memory coils in tandem in a cuff matched the pressure needed to support a human in space.
Modern space suits achieve this pressure by essentially putting the in a gaseous chamber but these future space suits would achieve this pressure by mechanically squeezing around the astronaut. This means that these future space suits would be incredibly less bulky than the space suits of the present day.
Another unique feature of a space suit composed of shape memory alloys would be that it could squeeze around an astronaut when it reverts to its original shape and then when cooled it would stretch and allow the astronaut to exit.
There are still many design challenges before this suit becomes a reality but the concept still is incredibly exciting as we may soon see the sleek space suits of science fiction.
References and Further Reading