Mars Express

Mars Express was the first planetary mission ESA ever attempted, pairing an orbiter built to map the surface and sound the subsurface for water ice with the British-led Beagle 2 lander. The orbiter reached Mars and went on to a long and productive career, but Beagle 2 fell silent after its 25 December release and was given up for lost. Its fate stayed a mystery until 2015, when imagery from orbit revealed it had touched down intact, only for two of its four solar panels to fail to unfold and block its antenna.