S.1 Spacecraft Propulsion Systems Chapter 1: Introduction to ...

- 16-
S.8 Classification of Propulsion Systems
Spacecraft propulsion can be classified according to the source of energy utilized for the
ejection of propellant:
Chemical propulsion use heat energy produced by a chemical reaction to generate
gases at high temperature and pressure in a combustion chamber. These hot gases are
accelerated through a nozzle and ejected from the system at a high exit velocity to
produce thrust force.
Electric propulsion uses electric or electromagnetic energy to eject matter at high
velocity to produce thrust force.
Nuclear propulsion uses energy from a nuclear reactor to heat gases which are then
accelerated through a nozzle and ejected from the system at a high exit velocity to
produce thrust force.