The Mariner program was a program conducted by the American
space agency NASA in conjunction with Jet Propulsion Laboratory
(JPL) that launched a series of robotic interplanetary probes
designed to investigate Mars, Venus and Mercury from 1962 to
1973. The program included a number of firsts, including the
first planetary flyby, the first pictures from another planet,
the first planetary orbiter, and the first gravity assist
maneuver. Of the ten vehicles in the Mariner series, seven were
successful and three were lost. The planned Mariner 11 and
Mariner 12 vehicles evolved into Voyager 1 and Voyager 2 of the
Voyager program, while the Viking 1 and Viking 2 Mars orbiters
were enlarged versions of the Mariner 9 spacecraft. Other
Mariner-based spacecraft, launched since Voyager, included the
Magellan probe to Venus, and the Galileo probe to Jupiter. A
second-generation Mariner spacecraft, called the Mariner Mark II
series, eventually evolved into the Cassini–Huygens probe, now
in orbit around Saturn. Basic layou