Cassini is a space mission launched in 1997 to explore Saturn, its rings and moons, a project of NASA, European Space Agency, and the Italian Space Agency (ASI). It includes 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 first 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) doing riskier research before crashing into Saturn's atmosphere to destroy it, which was done on September 15, 2017. The final orbits were very close to the rings and Saturn's atmosphere, to view them more closely.
The Radar includes SAR, "Synthetic Aperture Radar Imager" which uses the change of position of the spacecraft to simulate a larger aperture and produce detailed three-dimensional maps.
The Cosmic Dust Analyzer (CDA) measures 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. Thirty six extra-solar dust grains have been reported (velocity much higher than the Sun's escape velocity), which show an unexpected degree of uniformity.