<Tr> <Td> New Horizons </Td> <Td> 2007 gravity assist </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> 2015 flyby </Td> </Tr> <Tr> <Td> Juno </Td> <Td> 2016--orbiter </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> </Tr> <P> The exploration of Saturn has been solely performed by crewless probes . Three missions were flybys, which formed an extended foundation of knowledge about the system . The Cassini--Huygens spacecraft, launched in 1997, was in orbit from 2004 to 2017 . </P> <P> Saturn was first visited by Pioneer 11 in September 1979 . It flew within 20,000 km of the top of the planet's cloud layer . Low - resolution images were acquired of the planet and a few of its moons; the resolution of the images was not good enough to discern surface features . The spacecraft also studied the rings; among the discoveries were the thin F - ring and the fact that dark gaps in the rings are bright when viewed towards the Sun, or in other words, they are not empty of material . Pioneer 11 also measured the temperature of Titan at 250 K . </P>

When was saturn last visited by a spacecraft