reply to post by Manasseh
Manasseh.....you asked about rocket thrust, in a vacuum, then cite a Wiki article about jet aircraft engines in the Earth's atmoshere??
Have you caught your mistake yet?
Let's simplify (assuming your are serious with your question, and not just playing everyone for a fool).
Find a ballon. Blow up balloon. Release balloon. Observe results.
Yes....you do this experiment, here on Earth, since you have to be able to breathe. The balloon, not being very aerodynamic, naturally travels a very
erratic path, as the air exhausts.
NOW, try a thought experiment....a vacuum, a balloon, and a way to fill it with air. NOW, release it......it will travel straight and true (except
for the obvious effect of gravity....which will cause it to describe an arced path) Or, because of the flexibility of the rubber, the opening may
flop around, and that will affect it's direction of movement...so THEN gravity will be less effective of an influence.
Take ths balloon into a freefall (or 'microgravity) vacuum environment, and repeat. It will travel in one direction, with the proviso that the
previously mentioned problem of the soft nozzle might result in vector changes....but once all air is exhausted, the last thrust vector will result in
a course for the balloon that will not change, unless acted on by some other force....a wall, for instance.
Spacecraft can 'gimble' their engines, thus maintaining a desired thrust vector, while the fuel exhausts, and propels them in the opposite direction
of the exhaust thrust.
Currently, the Space Shuttle uses a combination of fuels....during launch, the big orange tank (the one with the 'foam' problem) is filled with LOX
and LH....(no, LOX is liquid oxygen, not smoked salmon)
The two elements, liguid O2 and liguid Hydrogen, when combined, produce a very strong reaction....that is pumped and directed to the three main
engines. ALSO, there are two Solid Fuel Boosters (acronym 'SRB') that, well....simplest way to describe them is what you see in a 'bottle rocket'
on the Fourth of July. Once lit, they burn, man...burn! Until they burn out, and are jettisoned, as is the main fuel tank.
On orbit, now you have the OMS....Orbital Maneuvering System...engines....they are 'hypergolic'. Wiki could help you learn more about that. In
addition, for minor orientation changes, such as for docking, or orienting for re-entry....or just to stabilize spacecraft temperatures in the hot
sun, are the RCS...reaction Control Thrusters....also hypergolic.
Does any of this help you understand better? Hope so.