Jim LeBlanc in the vacuum chamber before he lost pressurization and consciousness (Credits: NASA)

Jim LeBlanc in the vacuum chamber before he lost pressurization and consciousness (Credits: NASA.)

What happens when a space suit depressurizes in vacuum? On December 14, 1966, NASA spacesuit technician and test subject Jim LeBlanc found out. Suited up in an early Moon suit prototype, he entered a triple-doored vacuum chamber. Then, his pressurization hose somehow became disconnected and LeBlanc became the only person to survive near-vacuum pressures when his suit dropped from 3.8 psi to 0.1 psi in 10 seconds.

“As I stumbled backwards, I could feel the saliva on my tongue starting to bubble just before I went unconscious and that’s the last thing I remember,” recalls LeBlanc.

“Essentially, he had no pressure on the outside of his body and that’s a very unusual case to get,” explains Cliff Hess, the supervising engineer. “There’s very little in the space medical literature about what happens when you have that. There’s a lot of conjecture, that your fluids will boil.”

The chamber – which would normally take 30 minutes to repressurized – was blasted back to atmospheric pressure in 87 seconds. Amazingly, LeBlanc survived with just an earache to show for his ordeal. That really was a close call in the spaceflight history.

Watch the test here:


About the author

Merryl Azriel

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Having wandered into professional writing and editing after a decade in engineering, science, and management, Merryl now enjoys reintegrating the dichotomy by bringing space technology and policy within reach of an interested public. After three years as Space Safety Magazine’s Managing Editor, Merryl semi-retired to Visiting Contributor and manager of the campaign to bring the International Space Station collaboration to the attention of the Nobel Peace Prize committee. She keeps her pencil sharp as Proposal Manager for U.S. government contractor CSRA.

One Response

  1. Alexey U.

    It is from “Moon_Machines” Part 5 “The Space Suit”, near 33:00

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