text: how do i make a water bottle rocket more aerodynamic? we are given a 3 liter bottle that will be filled up with 30%water and compressed air. school project and i cant weigh more than 800 grams. you could try making a nose cone for it. normally, when these soda bottle rockets are launched, they are launched with the "bottom"/blunt end facing up, this is not very areodynamic.  you could perhaps fashion a pointed nose cone (out of paper?) to fit over the top of the rocket.