Launchpad: Firing the Space Shuttle Main Engines

[letsgetverydrunk]

the space shuttle is AMAZING! there is so much scientists and engineers had (and have) to take into account, it's a miracle it exists!!! makes me proud and want to do my best for humanity :D

[kinsley2108]

She's hot.

[sulijoo]

When I was at school a bunch of us would go down a local park at lunchtime and create hydrogen explosions. We'd add some aluminium foil to some caustic soda, collect the resulting hydrogen gas in a plastic bag attached to it...then light it! Boom.

[lievenaw]

"rockets are just controled explosions" say that to the challenger

[Boy75402]

@lievenaw

It's true for all rockets.

The difference is that once structural failure of the Challenger tank occurred, the explosion went from controlled (useful), to uncontrolled (deadly).

[djsparkyful]

I'm not a rocket scientist and would like to know how the engines burn hot enough to melt iron according to the video, but still remain useable, also I was under the belief that Hydrogen and Oxygen produce water, are these liquids being burned seperately? if not what is stopping them from becoming water? How does this work? A layman's explanation would be appreciated.

[sbrafk]

@djsparkyful There are alloys out there (such as nickel based ones) that can resist stress at tremendous temperatures. I'm not sure exactly what the engines are made of.

Hydrogen comes from a separate tank, injected (think cars with fuel and air), mixed with liquid O2, reacts, steam comes out of the nozzle producing thrust.

[Boy75402]

@djsparkyful

If you look at the engine bell, you'll see these pipes running along it. Fuel is channeled through those pipes in their way to the ignition chamber, carrying away some heat with it, and cooling the engine bell.

[Boy75402]

@djsparkyful

It's true that combining oxygen and hydrogen create water, but it also makes a lot of heat. So the water (steam) expands, creating thrust.

[Au197]

@djsparkyful  the hydrogen and oxygen ARE making water at tremendous temperatures. Thus, it comes out as super high pressure steam. It's a STEAM ROCKET. Talk about "steam punk". The combustion chamber and bell are cooled by regenerative cooling. Super cold liquid fuel is forced through channels in the walls and then flows to the injector plate. The fuel is heated and this helps with the burning. If this flow stopped for a instant the engine would melt.

[henik9]

Sounds like a horrible idea. Why use old technology that's been around for 40+ years when you could research newer/faster/cheaper ways of getting to orbit?

[checkplus]

@henik9

There's a lot to be said for reliability. Sure, it's always a good idea to research other ways of getting up there, but the newer idea isn't always the best.

[mickeypopa]

@checkplus

Yeah, safety comes first, innovation second.

It's not like there's an unlimited supply of astronauts xD

[IgnisInCaelum]

@mickeypopa: There's still something to be said for giving the ones we do have chances to do useful things before they're too *old* to.

[beeohhski]

all comments above this one are now facts of life

[puncheex]

...except Constellation. :(