I love this one. Of all the various homemade flying machines in the book, this is the most exciting and satisfying. It’s just far better than you expect it to be (it was certainly far better than the rest of my long-suffering family expected when I gathered them around to watch).
It’s incredibly simple to make and launch, and works on exactly the same principle as the Saturn V moon rocket. Using nothing but water and a bicycle pump, it will launch a completely standard 2-liter soda bottle 50 feet into the air.
YOU’LL NEED
HOW TO DO IT
1. You’ll probably need to cut a third or so off the length of the cork in order to be able to push the needle adapter all the way through. It’s easily done with a bread knife.
2. Push the needle adapter lengthwise through the middle of the cork using the hole left by the corkscrew as your starting point. Again, this is easier than you think it’s going to be (provided it’s a real cork and not a plastic one). See illustration to the right.
3. Fill the bottle with about a mugful of water: not much—definitely no more than a quarter full. Now stick the cork in the neck of the bottle. It should fit nicely. Firm but not immovable.
4. Choose a nice open space outside and stick the garden fork in the ground at a very shallow angle. The handle is going to be your launch pad.
5. Screw the bike pump onto the end of the needle adapter, then rest the bottle upside down on the handle of the fork.
6. Start pumping and commence the countdown: “Ten . . . nine . . . eight . . . seven . . . six . . . five . . . four . . . three . . . two . . . one . . . BLASTOFF!”
