Water Bottle Rocket Materials

Here's a list of materials that you might need in order to produce your water bottle rocket:

water bottle(s) - two-liter, not scratched. The bottle opening must be large enough to fit on the launcher (every now and then you get one that doesn't). manila folder(s) - preferably recycled duct tape scissors PlayDoh or home-made alternative (one-bottle rocket, optional for two-bottle rocket) box cutter or knife (two-bottle rocket only) kitty litter (two-bottle rocket only) markers