← All stories
Science

NASA Engineer Built Mercury-Powered Ion Engine That Ran for 11 Years Despite Toxicity

The Why Files · Project Chronos | Hitler's Last Weapon · July 3, 2026
NASA Engineer Built Mercury-Powered Ion Engine That Ran for 11 Years Despite Toxicity
The Why Files
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.

About this episode

The Y Files host AJ examines claims that Nazi Germany developed an anti-gravity weapon called Die Glocke (the bell) during World War II and traces alleged connections to modern US Navy patents for advanced propulsion technology. The episode explores how ancient Indian king Bhoja wrote about mercury-powered flying machines in 1010 AD but deliberately withheld construction details due to mercury's toxicity. AJ details how the Nazis allegedly attempted to build a bell-shaped device powered by counter-rotating mercury cylinders that could warp time and gravity, though project leader Hans Kammler and the bell itself disappeared at war's end. The episode reveals that NASA engineer Harold Calfman successfully built a mercury-powered ion engine in the 1960s that operated for 11 years on the SERT 2 satellite before the program was abandoned due to mercury poisoning of workers. In 2017-2018, aerospace engineer Salvatore Pais filed multiple US Navy patents for gravity-warping, cloaking, and advanced propulsion technologies allegedly based on spinning charged matter, with the Navy claiming the technology works and that China is pursuing similar capabilities. Most dramatically, the episode exposes how Apollo Fusion, Inc. nearly commercialized mercury-powered satellite engines in 2018 that would have released 20 metric tons of mercury annually into Earth's atmosphere before a UN treaty closed the loophole in 2022. AJ ultimately concludes that while the Nazi bell story lacks solid documentation and likely originated from a single journalist's unverified source, the recurring pattern of mercury-based propulsion attempts throughout history demonstrates humanity's repeated failure to heed ancient warnings about the metal's catastrophic toxicity.

Key takeaways

More stories More from The Why Files