Sad thing is, those balloons pop when they get too high. The density of air decreases, allowing the helium to push outward and pop the balloon. Had we made stro

Sad thing is, those balloons pop when they get too high. The density of air decreases, allowing the helium to push outward and pop the balloon. Had we made stronger balloons, we might have been able to just float up and collect them when we run out of light gases... Oh wait, that requires a balloon.