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NASA's Viking 1 landed on Mars on July 20, 1976, with Viking 2 following on September 3, 1976. The two captured 4,500 images of Mars as the first spacecraft to land and transmit data from the Red Planet successfully.
NASA’s Viking 1 and 2 missions tested soils for signs of life, captured images, and studied the Martian atmosphere, revealing evidence of ancient water flow, volcanic soil, and a thin carbon dioxide atmosphere.
NASA's Viking 1 landed on Mars on July 20, 1976, with Viking 2 following on September 3, 1976. The two captured 4,500 images of Mars as the first spacecraft to land and transmit data from the Red Planet successfully.
The most significant engineering challenge was slowing the Viking lander, which would move through space at nearly 29,000 kilometers per hour before reaching Mars. This required the invention of supersonic parachute technology, which is still used today.
NASA's Viking 1 and 2 missions revealed Mars' geological activity and potential for past life through their evidence of past surface water. Viking 1 held the record for the longest Mars surface operation until the Opportunity rover surpassed it in 2010.
The 21st century has introduced advances making telescopes, cameras, and computers powerful enough to detect the presence of molecules associated with biological processes in distant atmospheres, expanding the search for life to include unreachable worlds.
Three experiments on the Viking 1 and 2 landers searched for signs of metabolic activity in soil samples, indicating the presence of microorganisms. No definitive evidence of life was found in any experiment or lander imaging.
Radioisotope thermoelectric generators use a thermocouple—two plates of different metals joined at two junctions to make a closed circuit. When heating one junction while keeping the other cool, a voltage and an electric current are created.
The ArcJet Complex ionizes compressed air that fires onto shields at hypersonic speeds, replicating the conditions of high-speed, planetary reentry. An enhanced facility incorporates lasers to mimic the radiant heating experienced during high-energy atmospheric traversal.
The disk-band-gap parachute design was first developed for the Viking Project in the 1970s. Since then, it has been reinforced and uses stronger materials to handle larger payloads—including the 2020 Perseverance rover—landing it a world record.
The presence of river valleys, enormous canyons, and other structures carved by water on Earth suggests that water flowed abundantly across Mars' surface. The layering of rocks in the walls of these structures indicates the intensity and volume of these flows.
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