Rosetta was ESA's 2004-2016 comet-rendezvous mission. The Astrium-led orbiter used four planetary gravity assists and two asteroid encounters to reach Comet 67P/Churyumov-Gerasimenko, became the first spacecraft to rendezvous with and escort a comet, deployed the DLR-led Philae for the first comet landing, and concluded with a controlled descent onto the nucleus.
Alerts are unavailable because this mission is no longer active.