In the DST project, a deployable space telescope is designed for the thermal infrared spectrum. For this project, a new Systems Engineering (SE) approach was needed, since the SE was outdated and the project worked in silos. Important goals for the SE approach were that it was easy to use and minimizes the workload by automating as much as possible. It was found that an automated version of classical SE would be the most suitable. To implement this, a set of tools was created. In this SE Toolset the team members do their own SE part while the program handles the overall SE. The SE Toolset showed that it can provide a solution for the gap between classical SE and Model Based Systems Engineering (MBSE), without getting as complicated as MBSE. To improve the overall SE in the DST project, a top level trade-off was done to investigate the effect of different deployment options on the stowed volume. This trade-off was used to find a suitable concept for the DST TIR 30cm demonstrator mission. The DST concepts were also compared to reference satellites to determine if the concepts were state of the art and can compete with fixed telescopes. It was found that the DST concepts perform very well and outperform current existing telescopes.