The thermal modeling of small satellites (up to 100 kg) is crucial for predicting and managing their operation, and may present significant differences when compared to the thermal modeling carried out in relation to larger spacecraft. In this article, the modeling of their solar panels is underlined as one of these differences. The efficiency of spacecraft solar panels is affected by three main variables: the sun's irradiance, the cells' temperatures, and the operating voltage. Unlike the most common approach, which only takes into account the first two variables and decouples the thermal problem from the electrical one, the coupled thermo-electric problem of the solar panel efficiency as a whole is considered in this article. Using the UPMSat-2 mission as an example, the importance of considering the operating voltage in the thermal analysis of a mission is proven in the present article (for the prediction of temperature and generated power). A simple but accurate I-V (Current-Voltage) curve model to calculate panel efficiency is proposed for modeling the solar panels performance, this method being easily implemented in ESATAN ^© .

The integration of uncertainty analysis methodologies allows for improving design efficiency, particularly in the context of instruments that demand precise pointing accuracy, such as space telescopes. Focusing on the VINIS Earth observation telescope developed by the Instituto de Astrofísica de Canarias (IAC), this paper reports an uncertainty analysis on a thermal model aimed at improving cost savings in the future testing phases. The primary objective was to identify critical parameters impacting thermal performance and reduce overdesign. Employing the Statistical Error Analysis (SEA) method across several operational scenarios, the research identifies key factors, including the Earth’s infrared temperature and albedo, and the spacecraft’s attitude and environmental conditions, as the variables with major influences on the system’s thermal performance. Ultimately, the findings suggest that uncertainty-based analysis is a potent tool for guiding thermal control system design in space platforms, promoting efficiency and reliability. This methodology not only provides a framework for optimizing thermal design and testing in space missions but also ensures that instruments like the VINIS telescope maintain optimal operating temperatures in diverse space environments, thereby increasing mission robustness and enabling precise resource allocation.