July 20, 2016: NASA's Viking 1 Lander touched down on Mar

July 20, 2016: NASA's Viking 1 Lander touched down on Mars on July 20, 1976, making history as the first U.S. mission to successfully land a spacecraft on the surface of the Red Planet. Viking 1 was part of NASA's Viking mission, which included a second, identical spacecraft, named Viking 2. Today marks the 40th anniversary of the Viking 1 landing.