Access to the top of the shaft is restricted at these times. For curiosity's sake,we have dropped things like coins, pencils, etc, to observe the potential for damage or injury. Their terminal velocity seems very low as a result. When they hit, they bounce several feet high. While no one has volunteered to catch one, all agree that the impact might sting pretty good, but there wouldn't be any penetration or severe damage.
Pens are another matter.
It steered to the side and missed our plywood target, but shattered on impact. Well, if you called NASA, you didn't call the right person. That force is so small as to be virtually unmeasureable. Remember, it takes the entire earth to make you weigh 200 lbs or whatever. I don't think humans would do very well in a vacuum environment.