| This pic shows Mark undergoing orthostatic testing at the IMBP before starting training. This test evaluates the body's ability to adjust blood pressure under different gravity conditions. It simulates some of the effects of weightlessness on the blood supply and tests the body's ability to adapt. First the cosmonaut lies flat for 20 minutes, then he is rapidly lifted to 70 degrees (nearly vertical). At this angle, the body is fooled into thinking that it is not standing, so it doesn't try to push blood up to the brain, but gravity pulls the blood to the legs anyway. It's tough not to pass out. After 20 minutes nearly vertical, the cosmonaut is swung back and has to lie with legs raised 30 degrees, so the blood all rushes to his brain. Throughout, the doctors monitor a whole bunch of physiological statistics. |
