Armstrong line - Wiktionary, the free dictionary

• Armstrong's line

Named after Harry George Armstrong (1899–1983), who determined this limit.

Armstrong line

1. The altitude above sea level at which water boils without a pressurized environment, and at which a person would require a pressure suit or pressurized environment to survive, and avoid having their bodily fluids boil away.

   Synonyms: Armstrong's line, Armstrong limit

•   Armstrong limit on Wikipedia.Wikipedia