Chris Connors’ 10 Dollar Stomp Rocket Launcher looks pretty cool!
Stomp rockets are a great way to introduce flight, pneumatics, and energy transfer through hands-on learning. Paper rockets are very easy to make, and use “virtually free” materials. This will help encourage multiple iterations and exploration of rocket design. You should be able to focus on the important aspects of building and redesigning the rockets. The rockets themselves are very inexpensive, and there are lots of options for their redesign.