Cassini retirement

The Cassini space probe was deliberately disposed of via a controlled fall into Saturn's atmosphere on September 15, 2017, ending its nearly two-decade-long mission. This method was chosen to prevent biological contamination of any of the moons of Saturn now thought to offer potentially habitable environments. Factors that influenced the mission end method included the amount of rocket fuel left, the health of the spacecraft, and funding for operations on Earth.

Some possibilities for Cassini's later stages were aerobraking into orbit around Titan, leaving the Saturn system, or making close approaches and/or changing its orbit. For example, it could have collected solar wind data in a heliocentric orbit.