If one shoots a rocket, it moves forward because hydrogen (?) is burned. That “flame” creates the upward thrust. Once in space, a spaceship largely maintains its speed because there is no longer any air resistance. But what if such a spaceship needs to be adjusted? Is this possible with nuclear energy or solar energy, for example? Because nothing is burned here and there is no flame? How is it possible that you can adjust your ship with this?
Answer
Energy alone will not get you ahead.
That ‘flame’ creates an upward thrust because the gas molecules are shot away at a high speed and they exert a reaction force on the rocket. In space you have nothing to lift or push off, so the only way to change your motion is through the law of conservation of momentum, ie by blasting gas particles at high speed. This is usually done with a combustion, but it can also be done with the aid of an electric field.
To a limited extent, the gravitational pull of the planets can also be used to steer the course of a spacecraft (the so-called slingshot).
http://nmp.nasa.gov/ds1/tech/sep.html
http://www.mathpages.com/home/kmath114.htm
Answered by
Professor Walter Lauriks
Physics Acoustics
Old Market 13 3000 Leuven
https://www.kuleuven.be/
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