A spacecraft that orbits the Sun, a planet, or a moon. The best-known orbiters are those that have travelled to a distant planet to provide an intense study of its atmosphere and surface. These include Ulysses around the Sun, Cassini around Saturn, and Magellan around Venus.

An orbiter must be able to survive communication cut-offs when the object it orbits moves to a position between the craft and the Earth. It is also designed to overcome breaks in electricity production from its solar panels when the planet or moon blocks off the Sun.

NASA's official designation for the space shuttle vehicle. Although ‘space shuttle’ is the term used by the press and public for the orbiting spacecraft, NASA only applies that name to the orbiter and its rockets together.