On this day in space! Aug. 7, 1980: NASA's Viking 1 Mars orbiter shuts down 4 years into a 90-day mission

On August 7, 1980, NASA's Viking 1 Mars orbiter concluded its mission four years into a planned 90-day journey. Viking 1 was the first spacecraft to successfully land on Mars, part of a pair of Viking missions launched in 1975 to search for signs of life on the Red Planet. Each mission consisted of an orbiter and a lander. Viking 1's orbiter captured images of the Martian surface that assisted NASA in pinpointing the landing site for the lander.

After running out of maneuvering fuel, NASA had to shut down the orbiter. While the lander persisted for another three years before losing contact with NASA in 1983, the orbiter's final shutdown marked the end of its operational phase. Viking 1's mission is widely recognized for its successful landing, but it encompassed more than just the lander.

The orbiter, based on NASA's Mariner 9 spacecraft design, comprised three key instrument systems: an imaging system with two cameras, an infrared spectrometer for detecting water vapor, and an infrared radiometer for thermal measurements. The Viking missions were initially anticipated to operate for 90 days, yet both the lander and orbiter exceeded this expectation.

Viking 1 orbited Mars 1,488 times before its shutdown on August 7, 1980. During its extended mission, Viking 1 and its counterpart orbiter collaborated to capture 52,663 high-resolution images covering approximately 97% of Mars' surface, with each image resolution reaching about 984 feet (300 meters). Additionally, they photographed Mars' moons, Phobos and Deimos, in remarkable detail, surpassing the capabilities of the Mariner 9 orbiter in 1971.

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