why do astronauts wear spacesuit?

Answer 1

If they don't, the direct sunlight without an atmosphere would harm them severely. Also, they need oxygen, don't they?

Answer 2

Humans need to wear spacesuits because we want to keep our bodies intact. On earth we experience about 760 mmHG (also depends on elevation) due to air pressure. Our bodies exhibit the same amount of pressure, thus the pressure cancel out and we feel fine the way we are. In outer space, there is no pressure, thus our internal pressure would want to equilibrate with the pressure of space (pretty much zero).

Simply put, we don't want our insides to explode. Think of a balloon being filled up with too much air; pop goes the balloon (balloons pop because the internal pressure, inside, is a lot more than the external pressure, outside).

That's the primary purpose, we would want to also protect ourselves from radiation or other harmful substances, rays, energies (mentioned by several people who posted above).

Answer 3

The need to breathe is probably the most obvious reason that an astronaut needs to wear a spacesuit. But did you ever consider that a spacesuit is like a spacecraft only smaller? Like a spacecraft, the suit offers a stable environment to work in and protection from the harsh realities of space!

How Oxygen Moves in the Suit

On Earth, humans breathe by taking in oxygen from the air and exhaling carbon dioxide as waste from their bodies. In space, the Primary Life Support System (PLSS) on the astronaut’s back has to perform the same role in space: it has to provide oxygen and get rid of carbon dioxide.

Oxygen is a gas that’s moved throughout the suit using a closed-loop system—a system that measures and monitors how oxygen is being used, conserves and recycles oxygen, and if necessary, activates the secondary oxygen pack when oxygen pressure drops to a certain level.

Oxygen travels from the PLSS through a number of ducts built into the Hard Upper Torso and gets warmed up before getting passed up into the back of the helmet--this prevents the visor from fogging up.

The gas then travels from the back of the head, over the head, and down the front so that it can pick up the carbon dioxide and humidity that’s created as the astronaut breathes. From there, it travels down to the rest of the suit and collects heat, humidity from sweat, and any trace contaminants as it gets drawn towards the ducts built into the Liquid Cooling-and-Ventilation Garment (LCVG).

A fan sucks the "dirty" oxygen back into the PLSS to draw it through a Contaminant Control Cartridge. This cartridge filters out carbon dioxide and contaminants, while a heat exchanger and sublimator remove the humidity from the gas. The heat exchanger trades warm air being removed from the suit with cooler air coming into the suit. The plates in the sublimator freezes the water into ice. This ice is converted directly into water vapor that is released into space. This process removes heat from the water and so any water returning from the sublimator is very cold. This cold water mixes with any warm water that did not pass through the sublimator and then it travels back into the LCVG.

The remaining gas goes through a carbon dioxide sensor before it travels through the same loop again. More oxygen gets added from the supply in the PLSS as required.

Should the fan ever stop working, the Secondary Oxygen Pack gets activated: the closed loop is broken and an open loop is started. The oxygen will still follow the same path from the PLSS, but before it reaches the Contaminant Control Cartridge, it will get dumped into space.

Feeling the Pressure

On Earth, pressure is exerted in all directions. If there were no pressure, the air in our lungs would rush out. The gases in our body fluids would expand and boil off. That would mean game over!

No pressure is exerted in space because it is a vacuum. A vacuum can be described as the absence of matter. (In space, the gravitational attraction between planets and stars is low which means that that there are large gaps of nothingness between them. Any gas molecules that might be found floating between the planets and stars have such a low density that they’re considered of as non-existent.)

So, to ensure the astronaut’s survival in space, the suit needs to be pressurized. The suit’s pressure operates only at one-third of the pressure we experience on the surface of the Earth. That’s because the lack of pressure in space makes the suit act like a rigid balloon. Keeping the pressure as low as possible makes it easier for the astronauts to bend and move in the suit as they perform their tasks.

Therefore, the spacesuit is necessary in providing an environment that supplies oxygen for breathing and maintains pressure around the body.

Answer 4

The pull of gravity would crush them or something. The suit provides oxygen, pressure and protection from the cold (its cold out there isn't it?) plus it looks snazzy!

Answer 5

the suits are made to protect the astronauts while they do the excapades...

Answer 6

the suit has some essential things which are needed to survive in outer space

Answer 7

to protect against radiation and maintain pressure. also to avoid being hit by microscopic particles that could hurt them in space.

Answer 8

it is to protect them from evil space aliens that can take control of your body if you don't wear one.

Answer 9

they need to breathe too ...what do you want them to wear !!

Answer 10

Better question...when they fart in them...where does it go?