The goal was to provide a solution to the thermal problem of high-performing CubeSats. These CubeSat generate much heat due to a combination of increased power generation capabilities and miniaturisation. A deployable radiator is designed to solve this problem using HiPeR technology developed by Airbus Defence and Space Netherlands. This design is analysed, a prototype is produced and tested. The design is proposed after iteratively sizing the shape, dimensions, location of the interface and number of layers. The design is a T-shaped laminate of 12 sheets of PG, and a top and bottom protective sheet of Kapton adhered with 3M966. This shape allows for easy folding over the outside of a CubeSat to minimise volume while being compliant with the P-POD requirements. Some parts of the PG sheets are not adhered, allowing for local bending with a small bending radius. A tape spring hinge provides support and the actuation for deployment. The radiator allows for an efficient heat flow path between the payloads and space. This reduces the temperatures of the payloads and allows for CubeSats to continuously generate up to 30W of heat.