Power Contingency/Margin Methodology and Operational Envelope Analysis for PlanarSats

This paper presents a power-centric systems-engineering approach for PlanarSats andfor atto-, and femto-class spacecraft where surface-limited power dominates design. Wereview agency practices (The National Aeronautics and Space Administration (NASA),European Space Agency (ESA), Japan Aerospace Exploration Agency (JAXA)) and theAmerican Institute of Aeronautics and Astronautics (AIAA) framework, then extend themwith refined low-power subcategories and a log-linear method for selecting phase- andclass-appropriate power contingencies. The method is applied to historical and conceptualPlanarSats to show how contingencies translate into required array area, allowableincidence angles, and duty cycle, linking power sizing to geometry and operations. Wedefine the operational power envelope as the range of satellite orientations and conditionsunder which generated power meets or exceeds mission requirements. Consistent withagency guidance, sizing is performed to the maximum expected value (MEV) (CBE pluscontingency); when bounding or stress analyses are needed, we report the maximumpossible value (MPV) (Maximum Possible Value) by applying justified system-level marginsto the MEV. Results indicate that disciplined, phase-aware contingency selection materiallyreduces power-related risk and supports reliable, scalable PlanarSat missions under severephysical constraints.