The discharged used gas from rocket engines. Exhaust from a launch vehicle provides the power for a spacecraft's blast-off and thruster exhaust is used for its later orbital adjustment of attitude (see attitude control) and deorbit burn.
Exhaust velocity is the velocity of the exhaust from a rocket engine. A greater thrust is achieved by a higher velocity, which can be produced by the correct mixture ratio of fuel and oxidizer.
Subjects: Astronomy and Astrophysics.