We built an air cannon then filled it with 50-75 psi and shot rockets down the street. It got really fun when we added water. This is going to be great in the summer heat.
Thank you to THE KING OF RANDOM for showing how easy it is.
www.Masonthehowtokid.com
A fun idea would be to affix some sort of smoke-emitting device inside the rocket for a realistic trail! Anyone who figures out how to do this will be held in the highest regard. I ll give away a 3-month pro membership, too.