Tsiolkovsky rocket equation

The classical rocket equation, Tsiolkovsky rocket equation, or ideal rocket equation is a mathematical equation that describes the motion of vehicles that follow the basic principle of a rocket: a device that can apply acceleration to itself using thrust by expelling part of its mass with high velocity and can thereby move due to the conservation of momentum. The equation is named after—and usually credited to—Konstantin Tsiolkovsky, who derived and published the formula in 1903, though William Moore had outlined it as early as 1810 and elaborated further in a book published in 1813.

Source: Wikipedia — Tsiolkovsky rocket equation (CC BY-SA 4.0)