Humans experience physiological deconditioning during space missions, primarily attributable
to weightlessness. Some of these adverse consequences include bone loss, muscle atrophy,
sensory-motor deconditioning, and cardiovascular alteration, which may lead to orthostatic
intolerance when astronauts return to Earth. Artificial gravity could provide a comprehensive
countermeasure capable of challenging all the physiological systems at once, particularly if
combined with exercise, thereby maintaining overall health during extended exposure to
weightlessness. A new Compact Radius Centrifuge (CRC) platform was designed and built on
the existing Short Radius Centrifuge (SRC) at the Massachusetts Institute of Technology (MIT).
The centrifuge has been constrained to a radius of 1.4m, the upper radial limit for a centrifuge
to fit within an International Space Station (ISS) module without extensive structural
alterations. In addition, a cycle ergometer has been added for exercise during centrifugation.
The CRC now includes sensors of foot forces, cardiovascular parameters, and leg muscle
electromyography. An initial human experiment was conducted on 12 subjects to analyze the
effects of different artificial gravity levels (0g, 1g, and 1.4g, measured at the feet) and
ergometer exercise intensities (25W warm-up, 50W moderate and 100W vigorous) on the
musculoskeletal function as well as motion sickness and comfort. Foot forces were measured
during the centrifuge runs, and subjective comfort and motion sickness data were gathered
after each session. Preliminary results indicate that ergometer exercise on a centrifuge may be
effective in improving musculoskeletal function. The combination is well tolerated and motion
sickness is minimal. The MIT CRC is a novel platform for future studies of exercise combined
with artificial gravity. This combination may be effective as a countermeasure to space physiological deconditioning.