When we first moved in to our home four years ago, there weren't too many homes in the area.  There is a large park across the street so several of us bought a bunch of Estes rockets and would light them off in the park.  We'd have a blast launching them and letting the kids chase them down. Now that the neighborhood is essentially finished we don't do it much anymore, but with this article (make sure to watch the video at the bottom) I may have to start building rockets again, only much much larger rockets. My excuse could be that my son needs to work on his Astronomy merit badge. [Edit: Thanks to Rudeboy for pointing out a couple of additional videos, here and here]