The Viking spacecraft consisted of an orbiter, which would map the surface of Mars, and a lander, an automated robot biological laboratory which would examine samples of soil and search for life. The aim was to, for the first time, deploy a device that would actually come in contact with the Red Planet.
NASA scientists wanted to land directly on the surface of Mars. We had already accomplished a lunar landing, but we hardly knew Mars. Would the spacecraft sink into the soft surface dust, or would the ground be firm enough to support it?
In 1976 the twin spacecraft Vikings 1 and 2 were launched toward Mars. Each consisted of two parts, an Orbiter and a Lander. The Orbiters each weighed in at a slim 5000 pounds. The Orbiters would survey both the Martian landscape and its moons' landscapes. Inside the Orbiter waited the Lander. Just prior to each Lander's separation, intelligence tests would be administered to each of its two computers by a theoretically more intelligent computer on Earth. The failing computer--the dumb one--was turned off. The Lander would then emerge from the Orbiter as a butterfly does from a cocoon, stretching out its wings, and gently set itself down on the surface of Mars with about the same force as a person jumping from a one foot platform. The Landers would study soil samples and search for life.
Photo. The Vikings 1 and 2, left and right respectively. Both courtesy of NASA, JPL.
Mission to Mars. An educational site created for the ThinkQuest contest.