Double Bottle Rocket
Two bottles joined together increase capacity and thrust, allowing heavier payloads or higher flights.
Construction
- Cut the neck off a second bottle to create a joining sleeve.
- Insert the open ends of both bottles into the sleeve and tape securely with duct tape or heat-shrink plastic.
- Add fins and a nose cone as usual.
- Fill the lower bottle with water (¼ full) before launch.
Safety Notes
- Pressure limit remains 50 psi — more volume, not more pressure!
- Test for leaks before launch day.
Extension
Attach a light sensor payload or parachute system to test higher altitudes.