Development and testing of the DEAR 100 W flexible solar array blanket

Kurzfassung

The growing trend toward smaller, more compact satellites increases the demand for lightweight, deployable solar arrays. In response, the DEAR project - funded under ESA contract No. 4000133890/21/NL/MM/ra as part of the ARTES 4.0 programme - developed and tested a deployable 100W solar array designed to fit within a single CubeSat segment. Beyond strict volume constraints, the most critical requirement was ensuring a minimum operational lifetime of 5 years, with an end-of-life (EOL) power output of 100W. To guide material selection and mechanical as well as electrical sizing, this paper defines multiple reference mission scenarios and analyzes key space environment factors - such as radiation, atomic oxygen erosion, and thermal loads. Based on this analysis, the design ensures 100W power output at EOL, even under worst-case conditions. The array was manufactured using a semi-automated welding process for electrical interconnections, with a coated FEP supporting film for atomic oxygen resistance and polyimide reinforcements for mechanical robustness. Triple-junction GaAs solar cells were used as photovoltaic devices. As part of the DEAR system, the blanket underwent a qualification test campaign, including vibration and thermal-vacuum tests. This paper presents performance evaluations through multiple deployments, power output measurements (including IV-curve analysis), and electroluminescence inspections. This work establishes a validated design and manufacturing process for a flexible solar array blanket, qualified through extensive testing for diverse space mission scenarios.