Technicians working on the aeroshell of a Mars Viking Lander, 1974.

The aeroshell protected the Lander as it entered the atmosphere of Mars prior to landing on the surface. 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.