|Astronaut twins Scott (on the left) and Mike Kelly.|
Thanks to evolution, the human body is pretty well adapted to living on earth. Most of our physiology is based upon being pulled down on by a force of 9.8 m/s/s, and once you remove this force, strange things begin to happen. The biggest effect is felt in the astronaut's lower body, as this part (which has spent its entire existence supporting something) suddenly doesn't have anything to do. The load bearing bones (the legs, hips, and spine) begin to break down, releasing calcium into the body (doctors call this phenomena spaceflight osteopenia). This causes the bones to become more brittle, increasing the chance of a fracture. The release of calcium into the astronauts system can also increase the likelihood of kidney stones. This reduction occurs at a frightening rate, up to 1.5% of load bearing bone mass lost per month.
Alongside bone loss, astronauts also experience some degree of muscle atrophy. Much like the load bearing bones, the muscles in ones back and legs experience a reduction in use, which results in their weakening; without proper exercise, astronauts can lose up to 20% of their muscle mass in 5 to 11 days. Up until now, astronauts have bungie corded themselves to a treadmill, used a stationary bike, or have used a device called ARED (which simulates weightlifting) to help stave this off, but research is still being done to improve interstellar fitness.
|Body Fluid changes in Outer Space|
Why is all of this stuff such a big deal? Currently, we want to send people to Mars, a journey which will take six months with today's technology. Since there aren't any hospitals on Mars, anyone who goes there will have to be in a condition in which they'd be able to survive the harsh conditions of a foreign planet, which is something that hasn't quite been figured out. Hopefully NASA will be able to gain some important insights from the Kelly mission that will allow a better insight into how to treat space adaptation syndrome.
Posted by David Almanzar (Group A)