Originally Posted by tbzep

Two G-12's would get you 186 Ns total impulse, putting it into HPR rules anyway, if that's an issue at your field.

I understand what you're saying. I was thinking about smaller motors, which still would add weight over the single larger motor, but I haven't actually looked at the potential motor selection before now. You don't have anything that, flown in pairs would come close to meeting similar weight and thrust profile as a single G-12.

Apogee/Aerotech has a couple motors that are long burn, but their casings are similar in size to the G12 (the F13 uses the same casing) and would be about as heavy as a pair G-12's. To make it feasible they'd have to be nearly half the weight, and as a pair provide a good enough thrust profile to work with.