Take a rabbit, also called a hare, consider that this was conceived and patented by rabbits - yes, definitely a hare brained scheme.- On the analysis side, we have a picture of a 20 kilometer high sail, standing up at right angles, through areas where the air currents go as high as 300 Kilometers per hour(jet stream) and they feel this will stay standing. In my opinion, this will never be built. Small scale models will show the folly of this. By the way, at 65,000 feet, the lift of the helium filled top pocket will have near zero lift. Fools errand