Swing-by

A swing-by, also known as a gravity assist, is a space navigation technique where a spacecraft uses a planet’s gravity to change its speed and direction. By passing close to a planet, the spacecraft gains or loses energy without using extra fuel, effectively "bouncing" off the planet’s gravity field. This maneuver allows spacecraft to reach distant destinations more efficiently, saving time and resources. Think of it as a cosmic slingshot that helps a spacecraft accelerate or decelerate by harnessing the gravity of planets, enabling complex missions across the solar system.