Up for discussion is the two balloon scenario as mentioned on the latest LOHAN post.
Two balloons one high above the other both connected to a strain gauge type micro-switch on their tethers. When either one of the balloons burst its micro-switch fires the rocket. A timer is used to only arm the system only after a suitable delay after release to alloy the craft to enter the calmer air in the upper atmosphere.
1. Simple to build
2. Ensures maximum altitude before launch
3. Remaining balloon stabilises platform for launch
4. Fails safe, if one balloon burst early the rocket will still fire at altitude on the timer
5. Can be tested at low altitude