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

S.7 Effective Exhaust Velocity
F
ve = [m/s]
o
m
ve = effective exhaust velocity [m/s]
F = thrust force [N]
o
m = propellant mass flow rate [kg/s]
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From its definition as the thrust per unit rate of mass flow of propellant, it follows that ve is
numerically the same as the Isp as defined above with SI units of m/s.
Note: ve is the ‘effective’ exhaust velocity, - although called ‘thruster exhaust velocity’
hereinafter-, because it is determined by test; therefore, in all propulsion related calculations
with ve, the effective exhaust velocity has to be applied, if not stated otherwise.