Rocket Builder

Real rocket science, simplified: the Tsiolkovsky rocket equation, why rockets are ~90% propellant, the LOX-to-kerosene mixture ratio, thrust-to-weight, drag from a blunt nose cone, and why every tonne of payload costs speed. Kids see the actual math with their numbers plugged in.

A nose cone (to cut through air), a payload bay, a LOX (liquid oxygen) tank, a kerosene (RP-1) fuel tank, an injector + turbopump to mix the propellants, and engines. Miss a part and the simulation shows what really happens — for example, no injector causes a “hard start” explosion on the pad.

Solid boosters are simple and powerful but less efficient (lower Isp) — a one-stage solid rocket genuinely can’t carry enough energy to orbit. Real rockets use solids as strap-on helpers and reach orbit with efficient liquid engines and staging.

The tool prices engines, tanks, the injector, the nose cone, propellant, and launch operations, then divides total cost by the payload your design can deliver to orbit. Compare against Falcon 9’s roughly $2.7M per ton and try to beat it!