Can You Breathe in Space While Rockets Fire?

[sensor7]

If there is no atmosphere in space, than how could a rocket ship fire it's blasters on the way to the moon? Therefore I think there is an oxygen atmosphere in space, which should you should go ahead and be able to breathe it. If not than I don't see how the space shuttle uses fire based rockets.

 

[Nabeshin]

Hello and welcome to PF!

To a very good approximation, the space between the Earth and the moon (or anywhere in the solar system) is indeed a complete vacuum. No atmosphere, no nothing. You're quite right in thinking that oxygen is needed somewhere, but it is provided by the rocket mechanism itself by the oxidizer. So in the combustion chamber the fuel and the oxidizer are combined to create the chemical reaction, the very hot (read: fast) products of which are spat out the back of the rocket by the nozzle. Newton's 3rd law does the rest and you're in business.

 

[Matterwave]

Also please note that the requirement of oxygen for fire only applies for chemical fires (e.g. burning fuel...or basically all the fires you see in everyday life). The Sun, for example, has all that fire while its oxygen content is very low (<1%). This is because the Sun's fire basically just comes from it being so hot, the energy for which is provided by fusion.

 

[russ_watters]

I'd generally consider "fire" to be synonomous with combusion, which is a chemical reaction involving oxygen. So I wouldn't really consider the sun to be "burning", if we're being technical about it.

 

[Matterwave]

Yea, but to 99% of the population the Sun is a ball of fire in the sky...<_<

I made the post because I used to always wonder why the Sun can be on fire in an environment with no oxygen.

 

[Nabeshin]

I'd generally consider "fire" to be synonomous with combusion, which is a chemical reaction involving oxygen. So I wouldn't really consider the sun to be "burning", if we're being technical about it.

Agree. Always annoys me when popular science describes the sun as "burning hydrogen". To any physicist it's trivially obvious what is meant, but people without this background get too confused by the bad choice of words. Just say fusing. People can deal with that.

 

[Chronos]

Yea, but to 99% of the population the Sun is a ball of fire in the sky...<_<

I made the post because I used to always wonder why the Sun can be on fire in an environment with no oxygen.

Nuclear fusion is the short answer. It has nothing to do with oxygen. Gravity crushes hydrogen to its ingnition point.

 

[Matterwave]

Yes...as was my entire point...see post# 3