Idea for this Summer

I realized that I've got a considerable supply of model rocketry equipment, accumulated over the years, that's been largely unused. I really should have made use of that last summer. Oh well.

Anyway, this summer, I think I'd like to build a stand to fire some of the smaller engines horizontally. Not entirely sure how, but concrete is cheap. Figuring out how much I need would actually be a rare practical application of my high school physics.

I'd need to check the legality of this before beginning, of course.