Hybrid propellant rockets are a popular medium for students wishing to explore the world of rocketry because of the relatively low cost, easy handling and `green’ properties of their propellants. This project required the design and manufacture of a hybrid rocket motor to deliver 4000N of thrust, intended for use in a future sounding rocket flight vehicle. A donation of 50kg of 87.5% High Test Peroxide (HTP) led the derivation of the top-level parameters and determined the ultimate goal for a target thrust of 4000N to be demonstrated over two ten-second firings. High- Density Polyethylene (HDPE) was selected as the fuel for its availability, safety and, its performance alongside HTP. Fluid dynamics and thermal finite element analysis led the design of computer modelled parts that would interface into a modular motor. Design optimisation followed to reduce weight safely and to increase the performance of a future flight vehicle. The best example of this is the complex composite nozzle which replaced a heavy, steel nozzle, thus providing reusability and greatly reduced weight. Testing of the completed rocket motor is due to take place in September 2017, at a specialised test facility that will provide data in order to aid the future development of the motor. It is intended that future faculty projects will develop the rest of the sounding rocket around this motor, which has been kept modular to allow for easy interfacing and optimisation. Overall, the project so far has given unique opportunities in the design, manufacture, testing and outreach for high power rocketry that would otherwise have been impossible with a largely non-sponsored student budget.