Propellant mass fraction


In aerospace engineering, the propellant mass fraction is the portion of a vehicle’s mass which does not reach the destination, usually used as a measure of the vehicle’s performance. In other words, the propellant mass fraction is the ratio between the propellant mass and the initial mass of the vehicle. In a spacecraft, the destination is usually an orbit, while for aircraft it is their landing location. A higher mass fraction represents less weight in a design. Another related measure is the payload fraction, which is the fraction of initial weight that is payload.It can be applied to a vehicle, a stage of a Vehicle or to a Rocket Propulsion System.

The propellant mass fraction is given by the formula shown here.

Related formulas


ζpropellant mass fraction (dimensionless)
mffinal mass of the vehicle (kg)
m0initial mass of the vehicle (kg)