Dwight K. Elvey wrote:
  Hi
  I used to make saltpeter and sugar rockets when I was a kid.
 To bad one can't get saltpeter anymore without signing your life away.
 I used to have about a 75% successful launch rate. The others
 would tend to clog the nozzle and blow up on the pad. I even
 made a two stage that the second stage went out of sight. A
 couple minutes later, I saw the smoke trail and recovered the
 top stage. All great fun.
 Dwight
  
Why not turn your rocket hobby into profit. The X-Prize has not been
clamed yet. :)
For the the NON rocket-scientist type here is the link.
  
http://www.xprize.org/
Ben.