I needed a vessle to learn the accelerometer feature in the BBC microbit. I decided on a bottle rocket. The rocket contains a bottle, wich is pressurized with air and water. when released, the bottle will launch in a chaotic tumble, do to the bad aerodynamic shape of the bottle. To increase fligth duration, an aerodynamic covering was designed. The covering screws onto the threads on the bottle. Deployable drag surfaces provides spin for increased stability. The nacele is theaded to be easy to replace. Version 2 of the rocket has room in the nacele for both a battery pack and the microbit itself. version 3 is a ligther more refined covering. the nacele is still threaded, while the body sections is snap fit and easy to replace.