I went to a talk from a NASA engineer at my school once, and the thing that struck the me the most is the relative speed of objects in space. They design the sp

I went to a talk from a NASA engineer at my school once, and the thing that struck the me the most is the relative speed of objects in space. They design the space station to shield against small objects traveling at 20km/sec. In Gravity they see the the debris heading in their direction for dramatic effect, but in reality everything is traveling about 10 times faster than a typical bullet. It only takes a small chunk of aluminum to hurt very badly at that speed.