Make water bottle rockets. You shouldn't need more than a coke bottle, wine bottle cork, bicycle inner tube calve and matching pump. Optimal water level in bot

Make water bottle rockets. You shouldn't need more than a coke bottle, wine bottle cork, bicycle inner tube calve and matching pump. Optimal water level in bottle is ca. 1/3 IIRC, but figuring that out could be an interesting exercise. Or show them some SpaceX stuff with landings or how MSL/Curiosity landed on Mars, that kind of stuff.