ISS038-E-041406 (2 Feb. 2014) --- Japan Aerospace Exploration Agency astronaut Koichi Wakata, Expedition 38 flight engineer, gets a workout on the advanced Resistive Exercise Device (aRED) in the Tranquility node of the International Space Station.
Astronauts aboard the ISS do not feel the effects of gravity as we do on Earth. As the ISS orbits the Earth, both the vehicle and crew members are in a constant state of free-fall causing astronauts to experience a feeling of weightlessness. In this reduced-gravity state, it is easier to accomplish routine physical activities because they require less use of muscles. Since minimal to no exercise would result in muscle deterioration and bone density loss, astronauts are prescribed exercise routines. Astronauts are scheduled to exercise approximately two hours per day to maintain their health while on the ISS.
The Advanced Resistive Exercise Device (ARED) simulates the use of free weights. This device is used to maintain muscle and bone strength. The resistive force is generated by two piston/cylinder assemblies with an adjustable load. Astronauts can perform free-weight style exercises including dead lifts, squats, heel raises, hip abduction and adduction, bench press, bicep curls, tricep extension, and upright rows. The ARED is mounted to a Vibration Isolation System (VIS) installed between ARED and the ISS to limit forces transmitted to the structure of the ISS.
Understanding How Our Bodies Change in Microgravity
Before humans head to Mars, we want to know what challenges we will face. Long-term stays aboard the space station have allowed us to uncover and begin solving challenges that could be presented by the human body’s response to space. For example, some space station astronauts unexpectedly developed vision changes, now known as Spaceflight-Associated Neuro-Ocular Syndrome (SANS). Findings include swelling at the optic disc and flattening at the back of the eyeball. After helping discover the issue, space station research has served as a platform to better understand SANS.
NASA's Twins Study compared astronaut Scott Kelly during his year in space with his Earth-bound twin brother Mark Kelly. It provided insights into the many ways long-term spaceflight affects a human body. Findings showed that Scott’s gene expression changed and his body reacted appropriately to vaccines while in space.
Why do this in space? The space station currently is the only place for performing research in long-duration microgravity. There is no substitute for actually sending humans into orbit where they can serve as test subjects for the science.
Why does it matter? Traveling deep into space means spending long periods of time in microgravity. To figure out how to make those trips safer and more comfortable, it is important to study humans closer to Earth in a controlled environment.