spacecraft orbiting around a planet or other celestial body to act as a telecommunications relay or from which remote sensing observations can be made.
A spacecraft whose purpose is to orbit around an object like a planet or a satellite (moon).
man-made equipment that orbits around the earth or the moon
a small companion, always closely circling around your ship or travelling on its hull
a spacecraft that orbits a planet or moon without landing on it in order to study the object's surface from a safe distance
A spacecraft that goes into a sustainable orbit, either around the planet it is meant to be studying or around Earth in order to remain above the atmosphere.