There was a comment earlier that requires reiteration.
Two balloons, one above the other.
The top balloon is for primary lift and is inflated to the appropriate degree. A pressure sensor in that balloon is set to detect a rapid DROP in pressure and when detected to trigger the launch.
The bottom balloon is filled to only 75% of the amount the top balloon is filled to. It should NOT burst at the same time as the main balloon, but should provide enough lift to stabilize the platform during launch.
So, the top balloon bursts, triggering the launch of LOHAN.
The platform is kept stable and in the appropriate attitude by the second balloon.
The launch platform will continue to rise until the second balloon bursts.
The advantages of this system:
1. A simple, physical switch to effect the launch of LOHAN.
2. No need to measure altitude. The launch will occur at the maximum altitude a single balloon system would have achieved.
3. Actual altitude of launch can be inferred from the on-board cameras after the payload is retrieved.
1. Two balloons. SPB wasn't really hot on two balloons.
2. Twice the labour required to hold down the balloons during launch, e.g twice the beer.
3. How will a balloon filled to less than its maximum behave? Will it still continue to rise and burst?