Tsiolkovsky Rocket Equation

The ideal rocket relation Δv = ve·ln(m0/mf), linking a vehicle's change in velocity Δv to the effective exhaust velocity ve and the initial and final masses m0 and mf. It assumes constant ve, impulsive or continuous thrust in free space and neglects external forces, gravity and aerodynamic losses. The equation expresses the exponential mass cost of velocity increments.