I need help finding the most feasable way to immediately fill a 7 ft latex (but preferably Mylar, and probably the shape of a football due to the inefficiencies of a sphere) balloon by using a sytem packed into a 6 W x 6 L x 1 H inch rectangle. And by immediate, I mean at half the speed of a car's airbag. Should I use CO2 cartridges? If so how many grams? And how many cartridges? Should I use some kind of controlled explosion? If so, any ideas? Please keep your ideas within the range of safety, and off the shelf parts. Thanks!