I
Any of a series of large two-and three-stage launch vehicle s for spacecraft, developed by the U.S. beginning in 1958 and first flight-tested in 1961.
Saturn I, the first U.S. rocket specifically developed for spaceflight, was a two-stage vehicle; it and its Saturn IB derivative placed unmanned and manned versions of Apollo spacecraft into Earth orbit and launched unmanned satellites. Saturn V was the largest launch vehicle ever built by the U.S. and was used for the lunar missions of Apollo and to launch the Skylab space station .
II
Roman god of agriculture, equated with the Greek deity Cronus .
His wife was Ops, the goddess of plenty, and his children included Juno , Neptune , and Ceres . His festival, Saturnalia (beginning December 17), became the most popular Roman festival; its influence is still felt in the celebration of Christmas and the Western New Year. During Saturnalia, all business transactions were suspended, presents were exchanged, and slaves were given token freedom. The remains of Saturn's temple are located in the Forum in Rome. Saturday is named for Saturn.
III
Sixth planet from the Sun, named after the Roman god of sowing and seed.
The second largest nonstellar object in the solar system after Jupiter, it is about 95 times as massive as Earth and has more than 700 times its volume. Its outer layers are gaseous, mainly hydrogen. Models of its interior suggest a rocky core surrounded by a shallow layer of liquid metallic hydrogen encased by an envelope of molecular hydrogen. Saturn has at least 30 satellites (including Titan , the biggest) and an extensive ring system, with several main sections visible from Earth with a telescope. Saturn's rings, first observed in 1610 by Galileo , are made up of countless separate particles ranging mainly from inches to many feet in size but also including dust in some regions. Water ice observed on the surfaces of the particles probably constitutes most of the ring material. Saturn's day is about 10.5 hours; its year is 29.4 Earth years. Its rapid rotation, acting on electric currents in the core, generates a strong magnetic field and large magnetosphere. Its gravity at the top of its atmosphere is 16% greater than Earth's. Its average distance from the Sun is 887 million mi (1.43 billion km).