Cassini was a space mission launched in 1997 to observe Saturn, its rings and moons from close up, a project of NASA, European Space Agency, and the Italian Space Agency (ASI). It included a Saturn orbiter and a probe that landed on Titan (Huygens). The primary mission covered four years beginning in 2004 after the 7-year trip to reach Saturn. The mission was extended two years to 2010 (Cassini Equinox), then again for 6 1/2 years (Cassini Solstice) until 2017, with a final 10-month mission (The Grand Finale) carrying out riskier research, then crashing the spacecraft into Saturn's atmosphere to destroy it, which happened on September 15, 2017. The final orbits were very close to the rings and Saturn's atmosphere, to view them from as close as possible. Instruments:
The Radar includes SAR, "Synthetic Aperture Radar Imager" which used the change of position of the spacecraft to simulate a larger aperture and produced detailed three-dimensional maps.
The Cosmic Dust Analyzer (CDA) measured velocity, direction, and chemical composition of incoming dust by electrical measurements of ions and electrons, both of the particle and of the results of the collision, and by mass spectrometry of the results. Through direction and by comparing the velocity with escape velocities of the solar system, the planet, and nearby moon, it can be determined whether the dust grain is extra-solar, etc. As of 2016, thirty six extra-solar dust grains had been reported (i.e., with velocity much higher than the Sun's escape velocity), which showed an unexpected degree of uniformity.
Huygens instruments include: