MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging mission) (U.S.)

Destination: Mercury. Launched: Aug. 3, 2004. Arrival: 2011. Mission: To study Mercury from orbit for the first time. MESSENGER is intended to spend at least a year in orbit photographing the planet, studying its makeup, and charting Mercury's magnetic field.

Mars Exploration Rovers (MER) (U.S.) Ongoing MissionsMars Reconnaisance Orbiter (MRO) (U.S.)