Further development of the Delft Deployable Space Telescope (DST) was needed to solve for defocus due to thermal expansion. This thesis focuses on implementation of stray light design methodology on the deployable baffle to provide a more stable temperature environment. This methodology utilises various baffle shapes and the arrangement of vanes to absorb or reflect incoming light to the desired location. The effect on the thermal and stray light performance is analysed, to gather insight to form several baffle concepts. These are put in a trade-off with thermal and stray light performance in mind. The result is a deployable baffle using four vanes which increases the compliance to the defocus requirement by 28% for the visible light version of the DST. The baffle for the thermal infrared DST is a cylindrical baffle with one vane with a 100% compliance to the defocus requirement. The thesis provides the design of the baffle which reduces the defocus and reduces stray light.