RE: Flying wing gliding in high winds
PDN, your question did not state that the glider was controlled, and a 35,000 ft there is no slope lift...nevertheless, the statements I made are true. With reference to your question whether the the glider will 'fly backwards in a stable manner for some time' you should realise, by now, that the thing is never, at any pont, flying backwards. It is always flying at the trimmed speed as determined by its weight, elevator trim position and wing Cl. If gust stability is going to be a problem, then adding a little 'self righting' ability will take care of that. Perhaps the easist way to do what you are proposing is to simply launch a F/F, circle trimmed glider from the balloon and allow yourself and the balloon to descend at the same rate as the glider, though what you will do if the glider catches some thermal lift....
Evan, WB #12.