Launched on Oct. 15, 1997, the spacecraft entered orbit around Saturn on June 30, 2004 (PDT). After its four-year prime mission, Cassini's tour was extended twice. Beginning in 2010, Cassini began a seven-year mission extension in which it completed many moon flybys on Saturn and Titan. In April 2017, operators placed Cassini on an impact course that unfolded over five months of daring dives. On Sept. 15, 2017, the spacecraft made its final approach to the giant planet Saturn. But this encounter was like no other. This time, Cassini dived into the planet's atmosphere, sending science data for as long as its small thrusters could keep the spacecraft's antenna pointed at Earth. To its very end, Cassini was a mission of thrilling exploration.