On Aug. 7, 1980, NASA's Viking 1 spacecraft ended its epic and historic mission on the Red Planet. Viking 1 was the first spacecraft to successfully land on Mars. It was one of two Viking missions NASA launched in 1975 to go look for evidence of life on Mars. Each of the Viking missions were composed of an orbiter and a lander. Viking 1's orbiter took photos of the Martian surface that helped NASA decide where to drop the lander. After four years of orbiting Mars, the orbiter ran out of attitude