Question

U wanted to ask that how does a space suttle get its thrust in space?????

Answer 1

Vacuum is fine, Don't need to "push" against anything.

Rather it is conservation of momentum, the mass times velocity of the exhaust, m v, adds that much momentum in the opposite direction to the jet. If you are standing still on a skateboard and start throwing baseballs ahead of you, the board and you will start moving backward. Same principle.