Human Factors Psychologists Who Help Design Space Stations Found

Human factors psychologists who help design space stations found

A) that astronauts prefer rooms with clearly defined "up" and "down."
B) that sleep cycles must be carefully controlled in space to avoid disrupting body rhythms.
C) that privacy must be based mainly on temporarily blocking out visual and auditory contact with others, such as using eyeshades and headphones.
D) all of these are true.