A thruster is a spacecraft propulsion device used for orbital station-keeping, attitude control, or long-duration, low-thrust acceleration, often as part of a reaction control system. A vernier thruster or gimbaled engine are particular cases used on launch vehicles where a secondary rocket engine or other high thrust device is used to control the attitude of the rocket, while the primary thrust engine (generally also a rocket engine) is fixed to the rocket and supplies the principal amount of thrust.^{[1][2][3][4][5]}

Some devices that are used or proposed for use as thrusters are:

• Cold gas thruster
• Electrohydrodynamic thruster, using ionized air (only for use in an atmosphere)
• Electrodeless plasma thruster, electric propulsion using ponderomotive force
• Electrostatic ion thruster, using high-voltage electrodes
• Hall effect thruster, a type of ion thruster
• Ion thruster, using beams of ions accelerated electrically
• Magnetoplasmadynamic thruster, electric propulsion using the Lorentz force
• Pulsed inductive thruster, a pulsed form of ion thruster
• Pulsed plasma thruster, using current arced across a solid propellant
• RF resonant cavity thruster, an electromagnetic thruster using microwaves