Sweet Craig. I can get you the booster dimensions, but you're going to have a helluva time with the interstage posts. I'd just go CHAD and make it one solid tube up the sustainer.

Pete built this around the same time I built a gap-staged Standard Missile 2 ER. Both models staged well except when Pete tried a B4 for the upper stage once and it didn't ignite. My SM-2 had the problem where the booster was stable after staging and cored in most of the time. That lead me to work on some gap stage booster recovery ideas.

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