Recently, Riley and I completed the Cub Scouts' Pack 32 Space Derby. Months ago, I told Riley's den leader that I was enthusiastic to help with the derby, since it is one of my favorite scouting events. After a handful of emails, I found myself volunteering for a number of things related to the event, in addition to helping Riley with his rocket.
The derby itself is a race of propeller-driven rockets, flying down a length of taught fishing line. The rocket is made of two halves of balsa wood, hollowed out and glued together, then shaved and sanded to a rocket shape. A hanger is attached to the top of the rocket that allows it to slip into a cradle that hangs from the fishing line track. Rubber bands inside the rocket attach to the propeller in front and a small stationary dowel in the back. The propeller is wound, tightening the rubber bands, and when it is attached to the cradle and released, the rocket flies down the track!