Collaboration with European space agencies began in 1997 and has provided pictures of the moon, Titan, for scientists.
Nasa’s Cassini mission to Saturn is entering its final week. On 15 September, it will dive towards the planet and burn up in its atmosphere. Nasa have called it the grand finale.
Cassini is one of the most ambitious space missions. It is a collaboration between Nasa, ESA and the Italian space agency, Agenzia Spaziale Italiana. The spacecraft, launched on 15 October 1997, took seven years to travel through the solar system to Saturn, which lies about 10 times further from the Sun than Earth.