"If Astronauts must make repairs in a vacuum, why do they train in a swimming pool?"

To get used to the no gravity feeling

How about them #GammaRays feeling? #XRays? While riding in a metal craft? Oh and the micrometeroids flying at 20,000mph? What does the micrometeoroid due to a Kevlar suit when it's piercing it at 20,000 mph? What's the protocol an astronaut must take for a micrometeoroid breaching the suit? If humans are 70% water and water boils at room temperature inside of a vacuum...how would astronauts withstand -454°F temperatures? and #GammaRay's? and 20,000 mph #micrometeoroids?

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