Viking 1's Titan III-E rocket roared to life Aug. 20, 1975, as the spacecraft set forth on its nearly 500-million-mile journey to Mars. Fully fueled, the orbiter-lander duo weighed about 7,800 pounds.

Viking 1 launched 48 years ago this week and made history when it became the first spacecraft to land safely on Mars' surface and send images back to Earth.

NASA Viking missions and the search for martian life. In 1976, the Viking missions deployed two landers on Mars: Viking 1 and Viking 2, both equipped with a suite of scientific instruments ...

That’s where Viking 2 comes in. Same spacecraft, same experiments, but a different location. Perhaps the results would be different this time? “Again, we had the same results,” Lee says.

In 1976, the Viking missions deployed two landers on Mars: Viking 1 and Viking 2, both equipped with a suite of scientific instruments designed to search for signs of life.