Rocketry From First Principles

Most school rocketry is a craft activity with a physics label attached. This is the other way round. We start from conservation of momentum, derive the rocket equation on the board, and use it to work out why a single-stage vehicle cannot reach orbit no matter how much money you throw at it.

Then the students build. Every design decision they make has to be defended against the equation we just derived, which turns out to be a far better constraint than any marking rubric.

We fly at the end. Recovery is not guaranteed, which is also part of the lesson.

What people leave with

• The rocket equation, derived rather than quoted
• Why mass ratio dominates every other design consideration
• A design students can justify from physics rather than from a template