Cassini-Huygens, launched in 1997, was a joint mission between NASA, the European Space Agency (ESA), and the Italian Space Agency, ASI (Agenzia Spaziale Italiana). Cassini-Huygens is humanity’s first in-depth study of Saturn and its system of rings and moons. Its seven-year-long journey to Saturn included two gravity-assist fly-bys of Venus. Spacecraft use gravity-assists to increase their velocity.
Having exhausted its fuel supply, and to eliminate any chance of crashing into and contaminating potentially life-containing worlds, Cassini dove into Saturn on the morning of September 15th, to send data back to Earth until it finally disintegrates in Saturn’s atmosphere.