The Viking program consisted of a pair of identical American space probes, Viking 1 and Viking 2, which landed on Mars in 1976. The mission effort began in 1968 and was managed by the NASA Langley Research Center. Each spacecraft was composed of two main parts: an orbiter designed to photograph the surface of Mars from orbit, and a lander designed to study the planet from the surface. The orbiters also served as communication relays for the landers once they touched down.
Artist impression of a Viking orbiter releasing a lander descent capsule
Mars image mosaic from the Viking 1 orbiter
Streamlined islands show that large floods occurred on Mars. (Lunae Palus quadrangle)
Scour patterns were produced by flowing water. Dromore crater is at bottom. (Lunae Palus quadrangle)
Viking 1 was the first of two spacecraft, along with Viking 2, each consisting of an orbiter and a lander, sent to Mars as part of NASA's Viking program. The lander touched down on Mars on July 20, 1976, the first successful Mars lander in history. Viking 1 operated on Mars for 2,307 days or 2245 Martian solar days, the longest Mars surface mission until the record was broken by the Opportunity rover on May 19, 2010.
Viking orbiter/lander
Viking aeroshell
Launch of the Viking 1 probe (20 August 1975)
Proof test article of the Viking Mars Lander