Goals: The European Space Agency's Mars Express was designed to study the geology, atmosphere, surface environment, history of water and potential for life on Mars. It also carried Great Britain's Beagle 2 lander to Mars. The fast-track mission borrowed technology from the failed Mars 96 mission and the Rosetta comet-chaser mission.
Accomplishments: Mars Express was Europe's first mission to another planet. It provided subsurface measurements with the first radar instrument ever flown to Mars, and discovered underground water-ice deposits. It sent back mineralogical evidence for the presence of liquid water throughout Martian history and studied the density of the Martian crust in detail. The orbiter's unique orbit also has allowed it make up-closed studies of Phobos, the larger of Mars' two moons. The mission has been extended several times.
Mars Express delivered Beagle 2 as intended, but contact was lost with the lander before it reached the surface.