An idea I've been toying with... anyone try to design a rocket with the SLOWEST boost velocity? I'm thinking a cluster of A10s to get up to a minimum safe speed, then an E9 (or F10) to sustain the speed for the remainder of the boost. The rocket's mass would have to just balance the E9's thrust, and you'd need an overstable model since it would be flying on the low end of the safety margin. I figure it would be a nearly 2 lb model. Another option is the (obsolete?) D3, or some other low-thrust engine.