Following the launch of UKZN’s Phoenix-1A hybrid rocket in August 2014, a revised vehicle design is now under consideration to replace the P-1A technology demonstrator. Designated P-1B, the 13 km apogee workhorse is to be less expensive and easier to manufacture so as to provide a reliable launch system for ongoing research into hybrid propulsion technology and to promote human capital development in aerospace design and launch operations. Using UKZN’s in-house tools (the Hybrid Rocket Performance Simulator (HYROPS) and Hybrid Rocket Performance Code (HRPC)), the rocket will be designed to take into account the lessons learnt in the P-1A program. This paper outlines the progress made to date in the design of Phoenix-1B’s nitrous oxide/aluminum-paraffin wax hybrid motor.