The purpose of the thesis was to design a deployable thermal shielding baffle for the Deployable Space Telescope to reduce thermal gradients on the optical elements. As a result of a trade-off, the deployment was chosen to be based on an inflatable structure. The baffle consists of aluminium-kapton booms that form a cylindrical shape, and are rigidised after deployment through overpressurisation. Thermal shielding is provided by a blanket of multi-layer insulation surrounding the cylinder. Numerical analysis has shown that the baffle can withstand expected static and vibrational loads during operations, and preliminary thermal analysis results show that temperatures on the telescope are stabilised.