The Viking I Mission: Relive NASA's First Mars Landing 46 Years Ago

The Viking I mission was launched by NASA on August 21, 1975, containing an orbiter and a lander that landed on Mars 11 months later.

In 1964, NASA made its first attempt to reach Mars with the Mariner 4 mission to see if there were any signs of life on Mars. The first satellite was installed in Martian orbit in 1971, but NASA's first landing on Mars was made with the Viking I mission on July 20, 1976. 

A NASA event was held on August 21 to mark the 46th anniversary of the mission's launch, which marked the beginning of the landing of five rovers.

In Viking I, two large orbiters weighing 2,325 kilograms each carried a lander weighing 576 kilograms and formed the first mission of the Viking Project.

The Viking 1 launch took place on August 21, 1975, while the Viking 2 launch took place three weeks later on September 9, 1975. The Viking 1 lander touched down on Chryse Planitia on July 20, 1976, while the Viking 2 lander landed on Utopia Planitia on September 3, 1976, nearly a year after its launch. 

In order to detect potential life on the surface, each of these landers conducted three biology experiments after landing. The NASA experiments found an unexpected amount of chemical activity in Martian soil, but no evidence of life was found. 

In analyses of the lander's experiments, scientists concluded that living organisms cannot survive on Mars due to its self-sterilisation. It is believed that this blockade in the formation of life was caused by the sun's ultraviolet radiation, the extreme dryness of the Martian soil, and the soil's oxidizing nature.

It is safe to say that both the landers and their respective orbiters have exceeded their expected lifespans. It was expected that the Viking I orbiter would last only 90 days, but it ended its mission on August 7, 1980 after completing 1,489 orbits of Mars. The Viking II orbiter, however, served until July 25, 1978.