On March 2, 2004, the European Space Agency launched the Rosetta mission to study Comet 67P
Rosetta would later become the first spacecraft to orbit a comet. It was also the only mission to attempt a soft landing on a comet.Rosetta launched on an Ariane 5 rocket from French Guiana and spent the next decade chasing after Comet 67P. When it arrived in 2014, Rosetta dropped a small lander called Philae onto the comet. Philae had a rough landing and went missing after it tumbled across the comet.Rosetta’s cameras finally spotted Philae just three weeks before the end of the 12-year mission. In the end, Rosetta intentionally crash-landed into the comet.
Source:https://www.space.com/39251-on-this-day-in-space.html