In Europe there has been a comprehensive advance on the field of unmanned solar aircrafts during the past years. Improved solar cells and more efficient and lighter aircraft structures enable permanent stationing of solar powered drones, providing a variety of remote sensing capabilities. For this purpose, a combination of an efficient energy system and aircraft configuration is decisive . This is particularly true for the stationing of "High Altitude Pseudo Satellites (HAPS)" in the stratosphere. Within the scope of the collaborative project "Autonomy Considerations for Stratospheric High Altitude Pseudo-Satellites made in Bavaria (StraVARIA)", the DLR Institutes of Atmospheric Pysics and of System Dynamics and Control work on the subproject "Modeling, Control and Weather Detection (StraVARIA-DLR)" in order to increase the autonomy of HAPS platforms. The work encompasses the development of an integrated system model and a weather detection system for instrument flight as well as surveys concerning energy-optimized short-time autonomy. In detail, the involved DLR institutes strive for solutions of three scientific work objectives which are explained in the following: First, a flight control system will be developed which automatically preserves the functionality of a HAPS platform independent of control input from the ground station. Additionally, considerations of the total energy budget will increase safety and use potential. The second scientific objective includes the development of a weather detection system which supports the operator on the ground as well as the automatic control of the platform with distinct and easy to interpret data. This includes for example so called weather-induced "No-Go Areas". A better availability of information about weather hazards will lead to an improvement of the platform safety in manual as well as in automatic mode. The third scientific objective is to realize an integrated simulation which serves to verify the functionality of the developed technologies within the framework of the whole StraVARIA project