My training to become a space tourist

Professor Oleg Bondarenko, professor of life-support systems at the Yuri Gagarin Cosmonaur Training Center in Star City, instructs one of his slower students. You turn the regulator to off (with oxygen flowing in) to check that the suit is hermetically sealed. If it puffs up like a heavy balloon within 90 seconds, things are working! Of course, the suit becomes rigid because of the high pressure inside -- 1.35 times normal, or about 1100 mm of mercury, if I remember my lesson right. It's very difficult to do much at all when your suit is so puffy, especially if you can barely see from inside a scratched helmet. But I managed to open the valve...and lived to write this caption!