[Chief methods of modeling the biological effects of weightlessness]

The paper describes basic principles related to weightlessness simulation. In ground-based experiments zero-g is simulated with respect to the conceptual mechanisms of weightlessness effects on the body. The main components of the effects are considered to be elimination of deformations and fluid redistribution. The paper surveys and summarizes different methods of weightlessness simulation. It discusses advantages and disadvantages of water immersion, prolonged bed rest, hypokinesia, suspension in special devices with many degrees of freedom, walking on a treadmill at different angles, etc. The paper describes simulation of accentuated individual effects of zero-g during an exposure to longitudinal acceleration. It presents experimental physiological methods of simulation and symptoms of zero-g effects under normal laboratory conditions. The paper emphasizes inadequate use of some simulation techniques.