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NASA Engineer Built Mercury-Powered Ion Engine That Ran for 11 Years Despite Toxicity
The Why Files
Project Chronos | Hitler's Last Weapon
"In the early 1960s, Harold Calfman wanted the opposite of a rocket, not a single violent burst, a gentle push that never stopped. An engine that used very little fuel at once but kept running and running and running for months, maybe years. Take liquid mercury and boil it into a vapor. Hit that vapor with electrons to charge the atoms. Then throw the charged atoms out the back of the engine at tens of thousands of miles an hour. When it fired, it glowed a pale blue, the same pale blue the Germans saw coming off the Glocka. In 1970, NASA bolted Calfman's engine to a satellite called SERT 2 and waited for it to die. It didn't. They hoped it would run for 6 months. It ran for 11 years."
NASA engineer Harold Calfman developed the first ion engine in the 1960s powered by mercury vapor, which became one of NASA's greatest successes when tested on the SERT 2 satellite from 1970-1981. Despite its extraordinary efficiency and longevity, NASA abandoned mercury propulsion because it poisoned workers and posed contamination risks. The engine's pale blue glow reportedly matched descriptions of the Nazi bell weapon from World War II.
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