>> what will happen as the balloon goes up there will be less pressure inside and less pressure outside so the balloon itself will stretch. so you want to make it very, very light weight. so it's like stretching fabric, it will change shape. as it changes shape, that will put stress on whatever is fastened to it. and typically with something like this, you would fasten things on with whiide strips of tape, which works great. but when the balloon starts to change shape, it can put stresses on those attachment points. >> just so all of our viewers and all of the nonscientists can understand it, the principle is the same if you have a band-aid on your finger and you stretch out your finger, then that band aid becomes much looser and can then slip off. >> yeah. exactly. >> now, as far as the speed with which -- let's just assume that