Not so hard IMO, WW. All it takes is a valve and the comms to open it. The Japanese fusen bakudan of WWII would vent hydrogen at about 40K AGL automatically. Even with their crude tech they could have probably reached 45K AGL. Killed six people in CONUS! Just need a light sat tracker like my Spot that reads altitude and a valve that opens briefly every time you push a button. I'd use satcomm for tracking and ground-based HF for activation--simplex both directions to keep it simple on the experimental model. Heck, for $10K we could do strat and back next year IMO. With a scale model of course. Use Valtronic or EWA miniaturization for circuitry and we may never have to build a full-size strat. Now you know why I have come to WSGI town! :<) Have a good weekend, IndyJonesOhio.