The Viking Missions

The Viking spacecraft was made up of an orbiter and a lander. Langley awarded development of the orbiter to the Jet Propulsion Laboratory in Pasadena, California, which would also be responsible for tracking and data acquisition and its Mission Control and Computing Center. Martin Marietta Aerospace in Denver, Colorado was awarded the contract to engineer and build the lander. Two Viking spacecraft would be built and NASA assigned its Lewis Research Center to procure and configure the Titan-Centaur launch vehicles for each spacecraft. This program had the luxury of more than six years of research, design, development, testing and finally construction, and it had a budget to match. Nevertheless, there were breathtaking cost overruns with project Viking, with the final program cost

The Mars Pathfinder spacecraft is shown being mated to its third stage in the SAFE-2 building at Kennedy Space Center. Inside was the micro-rover Sojourner. Pathfinder was launched aboard a Boeing Delta rocket on 4 December 1996. (NASA)

The Jet Propulsion Laboratory (JPL) in Pasadena, California has remained in the forefront of planetary exploration in general, and robotic exploration of Mars in particular, for decades. Its sophisticated facilities occupy 177 acres, managed by the California Institute of Technology for NASA. (NASA/JPL-Caltech)

The Jet Propulsion Laboratory (JPL) in Pasadena, California has remained in the forefront of planetary exploration in general, and robotic exploration of Mars in particular, for decades. Its sophisticated facilities occupy 177 acres, managed by the California Institute of Technology for NASA. (NASA/JPL-Caltech)

estimated between at $700 million and nearly one billion dollars by the end of each mission.

Viking 1 was launched from Cape Canaveral Air Force Station on 20 August 1975, followed by Viking 2 on 9 September the same year. Viking 1 entered its Martian orbit on 19 June 1976 and spent one month imaging the Martian surface along its orbital plain, beaming its images back to Earth. The mission team selected Chryse Planitia as the landing site for Viking 1 and on 20 July, the lander separated from the orbiter and entered the planet's thin atmosphere, protected by its aeroshell and ablative heat shield. At 6 kilometers above the surface, the lander deployed its parachutes, the aeroshell was jettisoned, the lander's legs extended and finally the retrorockets slowed the spacecraft to a soft landing. Less than thirty seconds later, Viking 1 began transmitting its first photographic images from the Martian surface back to Earth and initiated its onboard experiments, starting its ninety-day mission.

Viking 2 began orbiting Mars on 7 August 1976. This time, the mission team selected Utopia Planitia, and Viking 2 landed there on 3 September. The images Viking 1 and Viking 2 beamed back to Earth were startling in their clarity and color, and they remain remarkable considering the technology of the time, even to this day. Both spacecraft far exceeded their engineering operating lives. The Viking 2 orbiter ceased functioning on 25 July 1978, but the Viking 1 orbiter continued to operate and send back data until August 1980 when its attitude control fuel was finally expended. The last transmission from the Viking 2 lander reached Earth on 11 April 1980, while the Viking 1 lander sent its final transmission on 11 November 1982. The scientific and photographic return from project Viking was considerable. They were the first probes to successfully land on Mars (previous attempts by Russian probes had failed), but they were nevertheless immobile and it was the dream of more than a few mission planners at NASA that perhaps one day unmanned rovers could be sent to the Red Planet. However, it would be decades before a new generation of Martian probes would again explore its surface.

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