With a few empty soda bottles and some PVC pipe, you can build a high-performance water bottle rocket.
I’ve been a big fan of model rocketry since I built my first Estes Alpha back in third grade. Nothing is more exciting to a 9 year-old proto-geek than launching a homemade rocket. But flying those one-shot solid-fuel rockets can burn a hole through a young hobbyist’s wallet faster than they burn through the atmosphere, and with today’s larger, high-powered rockets, locating and traveling to a safe and suitable launch site can require substantial planning and effort.
Instead, you can use 2-liter carbonated drink bottles to build an inexpensive, reusable water rocket. The thrill factor is surprisingly high, and you can fly them all day long for the cost of a little air and water. It’s the perfect thing for those times when you just want to head down to the local soccer field and shoot off some rockets!