Oberth effect

The Oberth effect is a phenomenon in rocketry that describes how a spacecraft can achieve greater efficiency and higher speeds when it performs maneuvers at higher velocities, particularly when close to a massive body like a planet or star. Named after the German physicist Hermann Oberth, the effect occurs due to the relationship between kinetic energy and velocity. When a rocket performs a propulsion burn (i.e., it fires its engines), the gain in kinetic energy is proportional to the square of the velocity.