Viking

Mission Profile

Viking comprised two identical NASA missions — Viking 1 and Viking 2 — each consisting of an orbiter and lander, launched in August-September 1975 aboard Titan IIIE/Centaur rockets and landing on Mars in July-September 1976 to conduct the first comprehensive biological search for life on another planet. The two orbiters mapped virtually the entire Martian surface at 150-300 meter resolution while the landers conducted meteorological measurements, seismic experiments, and three biology experiments designed to detect metabolic processes from any potential Martian microorganisms. The biology results were ambiguous and remain debated today, though the scientific consensus holds that the positive signals were chemical rather than biological in nature. Viking fundamentally transformed understanding of Mars and established the planetary protection protocols that govern all subsequent Mars missions.