Why do astronauts wear spacesuits during launch?

[jnb]

Why do astronauts wear spacesuits during launch? What scenario are they protecting against where the capsule is compromised but would survive sufficiently intact to make a spacesuit a necessity inside the capsule? I noticed on an old documentary that in the early Soyuz launches the cosmonauts did not wear spacesuits.

[Matt Scunthorpe]

I have wondered this myself. My guess is that it protects them while being shaken around, such as the suit is banging against the seat etc instead their body - will still feel it but must be softened.

Also i assume if the vehicle was damaged in terms of a puncher wound then they would have a supply of oxygen from their suits/packs plus would protect them in space if they made it out of the atmosphere with non fatal damage.

Matt

[rowan46]

I am not sure but escape velocity is something like 7miles per second at those sort of speeds you could be in the upper atmosphere  very quickly and if the cabin depressurises there isn't time to suit up

[bejay1957]

Didn't the procedure for the shuttle flights vary over the length of the program, unless my memory is playing tricks I thought that full suits were not always worn by all of the crew?

[Matt Scunthorpe]

The suit will also be fireproof, as well as having a cooling effects against the heat of the vehicle during launch.

Communication will also be fed through the suit to ground control and to the other astronaunts, as there will be alot of noise.

Matt

[Matt Scunthorpe]

Didn't the procedure for the shuttle flights vary over the length of the program, unless my memory is playing tricks I thought that full suits were not always worn by all of the crew?

I think it was to do with the seat sizes in the shuttles.

Matt

[Cornelius Varley]

i misread the title and couldn't think of a reason why they would wear their spacesuits during lunch

[Stu]

Why do astronauts wear spacesuits during launch? What scenario are they protecting against where the capsule is compromised but would survive sufficiently intact to make a spacesuit a necessity inside the capsule? I noticed on an old documentary that in the early Soyuz launches the cosmonauts did not wear spacesuits.

Didn't 3 cosmonauts die during re-entry because of a leak in the hull of their capsule? I assume they would have survived had they been wearing pressure suits.

I guess a similar thing applies during launch, it's a high risk time so best to be protected as much as possible. Granted in most circumstances it won't help much, but I think I would rather be over cautious!!

[Matt Scunthorpe]

Dont be confused with LAUNCH suits and SPACE suits.They are different things.

Matt.

[JB80]

Very good point.

http://en.wikipedia.org/wiki/Advanced_Crew_Escape_Suit

http://en.wikipedia.org/wiki/Launch_Entry_Suit

[JamesF]

Why do astronauts wear spacesuits during launch?

Because they'd look daft if they wore Batman outfits, obviously

James

[Zakalwe]

Many reasons.

The Shuttle crew used Advanced Crew Escape Suits to protect during the limited window they had to bail out in (though their chances if survival jumping into a supersonic airstream were pretty poor)

http://en.wikipedia.org/wiki/Advanced_Crew_Escape_Suit

Things can go wrong, quickly in launch/re-entry. For example the Soyuz 11 asphyxiated after undocking. A faulty valve bled the cabin atmosphere out and the unsuited crew died. If they had been suited then they would have had a chance.

http://en.wikipedia.org/wiki/Soyuz_11#Death_of_crew

In the Apollo era the crew wore the pressure suits to purge their bodies of nitrogen. Following the Apollo 1 disaster which directly stemmed from using a pure oxygen atmosphere, the cabin atmosphere was replaced with an O2/N2 mix. This atmosphere was gradually bled down to 5psia during launch and the atmosphere was replaced with a pure O2 atmosphere. If the crew were unsuited then they would have suffered the bends during launch. Before launch they were suited and breathed pure O2 (they carried a "suitcase" on the way to the spacecraft with O2 cylinders) to purge N2 from their bodies. Once in orbit, they were able to un-suit and work in a shirt-sleeve environment. During more dangerous phases, they suited back up to protect against a cabin de-pressurisation- for example during the LM docking and extraction.

[Astro Imp]

i misread the title and couldn't think of a reason why they would wear their spacesuits during lunch

Pleased to see that I'm not the only one who skims through topics to see if the thread is something of interest to me.