MESSENGER was a NASA robotic space probe that orbited the planet Mercury between 2011 and 2015, studying Mercury's chemical composition, geology, and magnetic field. The name is a backronym for "MErcury Surface, Space ENvironment, GEochemistry, and Ranging", and a reference to the messenger god Mercury from Roman mythology.

Mission type: Planetary Science · Orbit: Low Earth Orbit

Rocket: Delta II · Provider: United States Air Force