Astronauts experience a strong physiological deconditioning during space missions, primarily due to the weightless conditions. Some of these adverse consequences include bone loss, muscle atrophy, sensory-motor/vestibular deconditioning, visual impairment, and overall cardiovascular adaptation, which may lead to orthostatic intolerance when astronauts are exposed again to a gravitational environment. Physiological deconditioning will be even more challenging in future long-duration space missions, for example to Mars, in which astronauts will be exposed to weightlessness for six to eight months before landing without external help to support egress. In order to mitigate these negative effects, several countermeasures are currently in place, particularly very intensive exercise protocols. However, despite these countermeasures, physiological deconditioning still persist to a certain degree, highlighting the need for new approaches to maintain the astronauts’ physiological state within acceptable limits.
Artificial gravity (generated by centrifugation) has long been suggested as a comprehensive countermeasure that is capable of challenging multiple physiological systems at the same time, therefore maintaining overall health during extended weightlessness. However, human centrifuges hasn’t been tested in space, and there are still many questions about its implementation (including centrifuge configuration, exposure time, gravity level, gravity gradient, and use/intensity of exercise, etc). We want to investigate these research questions using a combination of human experiments on ground-based centrifuges and modeling techniques of physiological systems to complement the experimental results.