Thermal Design and Control of a PCB-based Solid-State Gas Generator (SSGG) Heater for Space Applications

Abstract

This thesis presents the development and experimental validation of a compact, solid-state gas generator (SSGG) heater integrated into a printed circuit board (PCB) for use in satellite deorbiting systems. Designed for CubeSat-class spacecraft, the system produces gas via the thermal decomposition of sodium azide (NaN₃). The project emphasizes minimal mass, low power consumption, and mechanical simplicity – key constraints for modern space missions. The heater system relies on Joule heating through patterned copper coils embedded within the PCB structure. NaN₃ is deposited into wells drilled into the board surface, where localized heating initiates its decomposition near 300°C. A range of PCB configurations were designed and fabricated to assess the influence of geometric and electrical parameters on thermal performance. Experimental testing revealed that higher initial coil resistance correlates strongly with improved thermal localization and efficiency. Coils placed within inner copper layers offered greater thermal retention and structural robustness, while strategic reductions in copper area around the wells enhanced heat focus. These findings guided the development of a final 6-layer modular design capable of achieving the desired decomposition temperature reliably and repeatably. The result is a 4x4 array of compact heating elements, each functioning independently but integrated into a unified architecture scalable to different mission sizes. Additional features, such as edge-mounted diodes and automated data acquisition, support precise control and monitoring during operation. Testing conducted in Earth conditions confirmed the system’s ability to reach decomposition temperatures, with improved efficiency anticipated in the vacuum of space due to reduced convective losses. This design provides a lightweight, manufacturable solution for small satellite missions and a foundation for future gas-based deorbiting technologies