Orbit insertion is a maneuver performed by an inter-planetary spacecraft designed to allow the spacecraft to be captured into orbit around a planet or other body such as a moon. The spacecraft approaches the planet at a speed greater than the escape velocity of the planet. The spacecraft must reduce its speed to below the planet's escape velocity. This is usually accomplished through a rocket firing (orbit insertion burn). The reduction in speed allows the spacecraft to settle into orbit around the planet. Aerobraking can also be used to slow the spacecraft, assuming the planet in question has an atmosphere. The Space Shuttle Discovery as seen from the International Space Station. ... m. ... The eight planets and three dwarf planets of the Solar System. ... A natural satellite is an object that orbits a planet or other body larger than itself and which is not man-made. ... A retrorocket is a rocket engine used for providing thrust to oppose the motion of a space vehicle, thereby causing deceleration of the vehicle. ... An artists conception of a spacecraft aerobraking Aerobraking is a technique used by spacecraft in which it uses drag within a planetary atmosphere to reduce its velocity relative to the planet. ...