Thermal model of the Mars Viking spacecraft, 1974.
© National Aeronautics & Space Administration / Science & Society
The spacecraft is being tested in the thermal vacuum chamber at the Jet Propulsion Laboratory (JPL), Pasadena, California. Two Viking spacecraft were launched towards Mars in 1975, each carrying a lander spacecraft and an orbiter. Both succesfully landed their probes on Mars to study the Martian environment, soil constituents and to search for simple life forms - none were found.