ESA-CNES' 1994 Long-Term Bed-Rest Study: 42 Days Of Head-Down Tilt, A Simulation For Long Duration Manned Space Flights.

In 1994, the European Space Agency (ESA) and the French Space Agency (CNES) organized a long-term weightlessness simulation based on bed-rest; this experimental campaign was contracted for its execution to the Institute of Space Medicine and Physiology (MEDES). Height healthy male subjects participated in this experiment and stayed in bed-rest in a head-down tilt position (-6° vs. horizontal) during 42 days. During this experiment, the responses of several physiological systems to weightlessness simulation were studied: i.e. cardiovascular system, renal function, adaptations to exercise, muscle tissues, bone, immune system and metabolism.