[GandalfTheGrey]

rockets are "things that GO!"

can someone give me a "rockets for dummies" introduction to how they work, or point me in the right direction?

ps I know I can just google it, but its better to have a thread where I can come back to to ask questions and stuff if need be

[Yeddi]

Oh man, rockets are easy as hell!

They burn fuel which shoots out the back and pushes the damn thing foreward. Blow up a balloon and let it go, that's the basics of rocketry.

there are solid fuel rockets and liquid fuel rockets, solid fuel rockets are simpler and more effective but are less stable as there is no way to stop them once started. The Space shuttle uses both, the boosters that get the thing into space are solid fuel, but the shuttle itself is a liquid rocket.

[Smilin' Dave]

solid fuel rockets are simpler and more effective but are less stable as there is no way to stop them once started

Liquid propellents actually tended to be me more unstable but for different reasons:
- The were often corrosive, and hence liquid fuelled rockets can't be kept fuelled indefinately.
- Alternatively they keep the components of the fuel seperate (binary) but this creates problems of getting the right mix.
- Liquid explosives (like nitroglycerene) tend to be fairly powerful and unstable (which is why you don't seem them used more often).

Another application for liquid propellent is for firing tank shells. But as noted above, getting the mix right is too much effort.

[GandalfTheGrey]

there are solid fuel rockets and liquid fuel rockets

OK, thats a good place to start - what is "solid fuel" and what is "liquid fuel" in terms of rockets?

[Yeddi]

Solid fuel were the first, so you have your gunpowder (not the same formula as the stuff you stick in guns which tends to explode but a 'slower' burning one) I don't know what else they use.. but they obviously don't load gunpower into the space shuttle Anyway this tends to be aranged around the edge of the rocket with a space in the centre for the gases to expand into and eventually out the nozzle to provide the force.

Liquid rockets you can use any combustable liquid (the first used petrol) and liquid oxygen which is combined and burnt and then the gasses expand out the nozzle. The reason why this is more complicated is cause of getting the mix right, and the use of pumps and all that jazz. I think most rockets use liquid Hydrogen as their combustable.

[Smilin' Dave]

I don't know what else they use

Apparently ammonium perchlorate is used as an oxidizer. I only know this because I saw a piece on a major industrial accident involving one of the US's biggest suppliers of it. Just to demonstrate that you can find all kinds of crap on Wikipedia:
http://en.wikipedia.org/wiki/PEPCON_disaster