ASK OCE — July 20, 2006 — Vol. 1, Issue 10
On July 20, 1976, the Viking I Lander made history by becoming the first spacecraft to safely land on another planet when it touched down on the surface of Mars.
The Viking mission employed two separate spacecraft, Viking I and Viking II, each of which consisted of an orbiter and a lander. The main mission objectives were to obtain high-resolution photographic images of the Martian surface, analyze the atmospheric and surface composition, and seek evidence of life on the Red Planet.
Viking I was launched on August 20, 1975 and arrived at Mars on June 19, 1976. It spent a month before its historic landing in orbit photographing the surface in order to find appropriate landing sites. Viking II, which was launched September 9, 1975, arrived in Mars orbit on August 7, 1976. Its Lander touched down less than a month later, on September 3, 1976. The Orbiters imaged the entire surface of Mars at a resolution of 150 to 300 meters, and selected areas at 8 meters. The lowest altitude for both Orbiters was 300 kilometers above the Martian surface.
The Viking Lander’s transmitted images of the planet’s surface, took surface samples and analyzed them for composition and signs of life, studied atmospheric composition and meteorology, and deployed seismometers.
The Viking II Orbiter was powered down on July 25, 1978 after 706 orbits, and the Viking I Orbiter on August 17, 1980, after over 1400 orbits. The Viking II Lander’s last communication was on April 11, 1980, while the Viking I Lander ceased communications on November 13, 1982. Together the Viking Landers transmitted over 1,400 images of their respective landing sites.