Specific impulse is a measure of the propulsion system’s efficiency and is expressed in units of velocity. It quantifies the change in momentum per unit mass of propellant consumed by the engine. Isp is typically measured in seconds (s) or meters per second (m/s). The higher the specific impulse, the more efficient the propulsion system is at generating thrust from a given amount of propellant. Specific impulse is often used to compare and evaluate different rocket engines and propulsion systems.Â
- Specific impulse (Isp) in m/s
- Thrust (T) in N
- Mass flow rate of the propellant (ṁp) in kg/s
- Acceleration of gravity (g) in m/s^2