This challenge was for us to create a water rocket out of a 2 liter bottle and other materials to go a distance not a height. I learned from my last rocket that a simple cone design with the natural 2-liter top (sprite) was a great cone. I then learned that having too much cone which I knew before but wanted to try was not good. The only thing I would change is to not have put a cone on my rocket on my second attempt.