Skylab Medical Experiment Altitude Test

The Skylab Medical Experiment Altitude Test, or SMEAT, was a 56-day simulation of an American Skylab space mission from 26 July-19 September 1972 at NASA's Manned Spacecraft Center in Houston, Texas. The astronauts in the test were Bob Crippen, Karol Bobko, and William Thornton, who simulated space experiments, housekeeping and leisure activities in a hypobaric chamber.

Source: Wikipedia — Skylab Medical Experiment Altitude Test (CC BY-SA 4.0)