Rotary chair experiments in Spacelab (2)

(Jan 30, 1992) Astronaut and physician David C Hilmers (b 1950), STS-42 mission specialist, wearing a helmet assembly, sits in the Microgravity Vestibular Investigation (MVI) rotating chair. The scene is in the International Microgravity Laboratory (IML-1) science module aboard Space Shuttle Discovery. Hilmers, a mission specialist, and six other crewmembers spent more than 8 days in Earth’s orbit conducting experiments. Hilmer's helmet assembly is outfitted with accelerometers to measure head movements and with visors that fit over each eye independently to provide visual stimuli. The chair system has three movement patterns: (1) "sinusoidal," or traveling predictably back and forth over the same distance at a constant speed; (2) "pseudorandom," or moving back and forth over varying distances; and (3) "stepped," or varying speeds beginning and stopping suddenly. (Source: NASA/Johnson Space Center [Houston]. NASA ID: STS042-27-037. Public domain.)