Why does an astronaut need to wear space suit?

If you have watched the 1981 sci-fi movie Outland you probably remember this scene: A mine worker is sent to the outer space (read Jupiter’s moon Io) where he rips open his spacesuit and what follows is simply horrifying. The air quickly leaks out, the internal pressure drops, his spacesuit decompresses and his body is exposed to vacuum, eventually leading to an explosion that proves to be fatal. We all know that astronauts wear space suits when they are on a mission. Now the question is, why are they so necessary? Let us find out together. 

Firstly, what exactly is a space suit? 
Well, as the term suggests, space suit is a uniform worn in the outer space. But is that all? The short answer is no. The long answer is, more than a suit, it’s a protective and pressurised piece of clothing, often paired with certain equipment.  

4 reasons to wear a space suit 
By now you all have understood that wearing a space suit is a must if one wants to come back alive. Here are the dangers that it protects astronauts against. 

Vacuum: The outer space comprises of vacuum, which can harm humans if they are exposed to it for too long. It has been found that in the absence of space suit, a person is unable to hold his breath for long which can eventually lead to collapsed lungs and ruptured eardrums. Actually, vacuum deprives the brain of its required oxygen and the outcome is fatal.  

Freezing temperature: The temperature in the outer space has an excessively cold climate with an average temperature of about minus 270.45 degree Celsius. So, it is impossible for humans to survive there without any protective layer like space suit.  

Harmful radiation: Wait, we aren’t done yet. Space also contains high amount of radiation that is toxic for the human body, even in small contents. Also, just like deep-sea divers, astronauts too are often in danger of falling prey to decompression sickness. For those of you who do not know about it, this is a fatal condition that occurs when bubbles are created in the bloodstream (from the dissolved gases).  Rapid decompression, showing signs of severe joint pains, skin irritation, nausea and eventual paralysis.  

Absence of air pressure: Space, most of you know, in a no pressure zone. In the absence of air pressure, the boiling point suddenly drops to human body temperature. But, what does this even mean? It means that the exposed liquids in the body, saliva and blood for example, will start boiling.  

This actually happened in 1966 when NASA space suit technician Jim LeBlanc accidentally got exposed to vacuum in a vacuum chamber (having identical conditions as that of space) as his space suit malfunctioned. Fortunately, he was only unconscious for about 10 seconds. When he regained consciousness, thanks to the efforts of his colleagues, he shared that his last memory was that of his tongue (read saliva) bubbling (read boiling).