It’s an automatic parachute deployment system that you build into the nose-cone of your rocket. The main portion of the build is made out of plastic soda bottles (2 liter size) to end up with a ...

The bottle rocket challenge: faces from across the BBC ... Dr Maggie Aderin-Pocock: If you want to make your rocket more aero-dynamic pop a cone on top and maybe a couple of fins at the side.