Since the internal atmosphere of the spacecraft is
controllable and has normal air, regular clothing can be worn by the astronauts.
However, a spacesuit or pressure suit is needed for outside space exploration.
The main purpose of the spacesuit is to protect human beings from an environment
that is different from Earth’s normal environment. Humans need protection from
the harsh elements of outer space, such as radiation, unregulated temperature, absence
of atmospheric pressure, and lack of oxygen.
The dry air on Earth’s atmosphere is made up roughly of 21
percent oxygen, 78 percent nitrogen, 0.93 percent argon, 0.038 percent carbon
dioxide, and small amounts of water vapor and gases. The atmosphere becomes
thinner as it goes higher in altitude into the five main layers: the troposphere,
the stratosphere, the mesosphere, the thermosphere and the exosphere. At 68
miles up, the imaginary line called the Karman line, is where space begins. In
space, the atmospheric pressure is extremely low, there is no oxygen, and the
temperature is extremely hot and cold.
The thin atmospheric pressure in space is not enough to
maintain a person’s normal blood pressure, causing the person’s body fluids to
boil and freeze. The spacesuit’s neoprene fabric restricts the air pressure within
the pressurized suit, thus supplying the proper air pressure when worn by the
astronaut and preventing the body fluids from boiling and freezing.
The lack of oxygen in space will cause unconsciousness and
death rapidly. Since the thin atmospheric pressure will cause low oxygen levels
in the astronaut’s blood and lungs, pure oxygen is used and flows into the
spacesuits through an umbilical cord attached to the spacecraft or a life
support system that is carried like a backpack.
The carbon dioxide that comes out of the astronaut would
build up to unacceptable levels when confined within the spacesuit. To deal
with this problem, the spacesuits are equipped with canisters of lithium
hydroxide, which are used to remove the carbon dioxide. The canisters of
lithium hydroxide are either accessed through the umbilical cord that is
attacked to the spacecraft or through a life support system that is carried
like a backpack.
Without the Earth’s atmosphere in space, the human body will
not be able to cope with the extreme hot temperature of the area facing the sun
and the extreme cold temperature of the area facing the dark space. The
insulation of layers of rubberized, breathing fabric and outer layers of
reflective material allow the space suit to deal with the extreme hot and cold
temperatures in space. Spacesuits use internal fans or water-cooled garments to
remove the body heat and the subsequent perspiration that is produced by the
astronaut during strenuous activities.
Aside from protecting the astronauts from the extreme
temperatures and thin atmospheric pressure, and providing oxygen for breathing,
the durable fabrics in the spacesuits protect the astronauts from micrometeroids,
which are very small pieces of rock or metal debris floating in space. The
reflective fabrics used in the spacesuits also give some protection from
radiation. The tinted domed helmets that come with the spacesuits are made of
durable, clear plastic that provide clear vision. The radio with transmitters
and receivers, in combination with the headsets, microphones, and earphones,
allow the astronauts to communicate with each other and also with the ground
controllers.
NASA’s Mercury program utilized the design of a U.S. Navy
Mark IV
pressure suit for its space orbital flight. The pressure suit was
modified by an addition of layers of silver Mylar on top of the rubberized
fabric. To allow mobility, break lines were sewn into the fabric in the area of
the elbows and knees. The Mercury spacesuit included boots with laces, gloves,
and a helmet with a collar ring. The oxygen hose was attached to the suit from
the space craft. The modified Navy pilot suit was worn by the Mercury
astronauts without pressure or unpressurized, which was in its “soft” state. The
purpose of the Mercury Project pressure suits was for backup only in the event
of loss in cabin pressure, which never occurred, and these were not intended
for space walking.
 |
| Gordon Cooper Source: http://www.nasa.gov/externalflash/ spacesuit_gallery/hi-resjpgs/1.jpg |
Gemini
 |
| Gus Grisson & John Young Source: http://www.nasa.gov/externalflash/ spacesuit_gallery/hi-resjpgs/4.jpg |
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| Neil Armstrong Source: http://www.nasa.gov/externalflash/ spacesuit_gallery/hi-resjpgs/3.jpg |
The Gemini-Titan 4 was the first American spacewalk.
Astronaut Edward White floated in zero gravity of space. He was connected to an
umbilical cord and a tether line, which were attached to the spacecraft. White
used a Hand-Held Self-Maneuvering Unit (HHSMU) to move around.
 |
| Buzz Aldrin Source: http://www.nasa.gov/externalflash/ spacesuit_gallery/hi-resjpgs/8.jpg |
Space Shuttle
 |
| Bruce McCandless Source: http://www.nasa.gov/externalflash/ spacesuit_gallery/hi-resjpgs/11.jpg |
Future Design
 |
| Professor Dava Newman Source: http://www.nasa.gov/images/content/ 617058main_45s_building_future_spacesuit3_full.jpg |
 |
| Source: http://www.nasa.gov/externalflash/spacesuit_gallery/hi-resjpgs/15.jpg |
The efforts to replicate the Earth’s environment inside the spacesuits have given humans the chance to explore space in relative safety. Although the functionality of these spacesuits is first and foremost at the core of its design, the iconic fashion of the bulbous suit makes it a favorite symbol of space exploration. The evolution of the spacesuit designs reflect new technologies, and will continue to evolve as new materials are invented and as we explore new frontiers in space.
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Freudenrich, C., & Ph.D.. (n.d.). HowStuffWorks "How Spacesuits Work".HowStuffWorks "Learn how Everything Works!". Retrieved May 7, 2013, from http://www.howstuffworks.com/
Earth's Atmosphere: Composition, Climate & Weather | Space.com . (n.d.).Space and NASA News – Universe and Deep Space Information | Space.com . Retrieved May 7, 2013, from http://www.space.com/17683-
Photos: Space Suit Evolution Since First NASA Flight. Retrieved May 7, 2013, from: http://news.
Nat. Geo. New Skintight Spacesuit Design Unveiled. (n.d.). Daily Nature and Science News and Headlines | National Geographic News . Retrieved May 7, 2013, from http://news.
Space Suit Evolution. (n.d). From Custom Tailored To Off-The-Rack. Retrieved May 7, 2013, from: http://history.nasa.gov/
Fenlon, Wesley. Jamie & Adam: Tested, Exploring the Aesthetics of NASA's Iconic Space Suit Design. Retrieved May 7, 2013, from: http://www.tested.com/science/
Suited For Space (Smithsonian Exhibition) Retrieved May 7, 2013, from http://www.sites.si.edu/
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