Astronauts on the International Space Station (ISS) have several exercise options lessen the negative effects of weightlessness in space. They spend a considerable portion of each day working out to ward off the long-term effects of weightlessness but many still suffer bone loss, muscle atrophy and issues with balance and their cardiovascular systems. Engineers at Massachusetts Institute of Technology (MIT) have built a compact human centrifuge with an exercise component- a cycle ergometer that an individual can pedal as the centrifuge spins.
Human centrifuges are spinning platforms that, at high speeds, generate forces that are strong enough to mimic gravity. An astronaut, riding in a centrifuge, would presumably feel the reinforcing effects of gravity.
The centrifuge at MIT has been sized to fit inside a space module of the ISS. This human centrifuge also has sensors to measure cardiovascular variables such as blood pressure, heart rate, respiration rate, muscle activity and foot forces.
Laurence Young from MIT's department of aeronautics and astronautics said, "With exploration-class missions like Mars, you could run the risk of having astronauts not sufficiently conditioned to perform effectively, and also to not be in good health when they finally get to the surface of Mars. A human centrifuge aboard a Mars-bound spacecraft would help keep an astronaut in shape over the months it would take to get to the Red Planet."
During the study, participants were asked to pedal for 15 minutes at three levels of resistance set by the cycle ergometer. The remaining ten minutes involved spinning up and slowing down the centrifuge. The study participants tolerated the experiments well, suffering little motion sickness even while spinning at relatively high velocities. As the centrifuge's spin was increased, raising its artificial gravity, study participants used correspondingly more force to pedal, an encouraging result.
Young said, "If we use artificial gravity, we are able to get higher foot forces that are good for bones and help you generate more bones. Artificial gravity would be a huge benefit for astronauts, particularly those embarking on long-duration space missions."
The results are published in the Acta Astronautica.