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Vestibular experiment in Spacelab (2)

(November 1, 1983) In this Spacelab-1 mission onboard photograph, astronaut, fighter pilot, and engineer Byron Lichtenberg (b 1948) performs a drop experiment, one of the Vestibular Experiments in Space investigations. The experiment examined spinal reflexes to determine whether they changed in microgravity. In Earth's environment, the otoliths signal the muscles to prepare for jolts associated with falling. During the flight, the normal reflex between the otoliths and the muscles was partially inhibited early in flight, declined further as the flight progressed, and returned to normal after landing, suggesting that the brain ignored or reinterpreted otolith signals during space flight. Crewmembers reported a lack of awareness of position and location of feet, difficulty in maintaining balance, and a perception that falls were more sudden, faster, and harder than similar drops experienced in preflight. Crewmembers experienced illusions as they performed prescribed movement tests. When crew members viewed various targets and then pointed at them while blindfolded, their perception of target location and position of their own limbs was inaccurate in flight compared with similar tests on the ground. Spacelab-1 was launched aboard the Space Shuttle Orbiter Columbia for the STS-9 mission on November 28, 1983. The Marshall Space Flight Center had management responsibilities for the mission. (Source: NASA/Marshall Space Flight Center [Redstone Arsenal, Alabama]. NASA ID: 8440350. Public domain.)