Dave, Our BP tests used excellent containment and we experimented with three methods:
1. containment with 1 atm pressure x
2. containment after a vacuum was applied xxx
3. containment but without 100% seal x
We are separating the satellite from the last stage, we are simply using methods other than a separate pyro charge or other things (springs, etc) to cause separation to save weight. I just read what I wrote before and that point is not clear. We are experimenting with a new propellant that would reduce the weight of the final stage and using and testing alternate methods of separation for the satellite that eliminate the mass of a separate device. We are having problems with our propellant 'detonating' if the conditions are not just right.