Damage-Quantified Reusability Evaluation of Reusable Launch Vehicle Avionics: A Framework Integrating Physics-of-Failure Modeling with Multi-Criteria Decision Making

Abstract

Reusable launch vehicles (RLVs) subject avionics electronics to repeated vibration, shock, and thermal cycling, yet no standardized method exists to evaluate reusability at the device level. We integrate physics-of-failure models—Steinberg vibration fatigue, Engelmaier/Coffin–Manson solder thermal fatigue, and Miner cumulative damage—with AHP-entropy multi-criteria decision making (MCDM). A flight-heritage 6-layer FR4 printed circuit board (PCB) from a rocket data-acquisition unit (108.25 × 108.25 × 1.62 mm, 109 components) is analyzed under Falcon 9 vibration and a DLR re-entry thermal profile (f1 = 310.2 Hz), with 11 core devices extracted from ODB++. Thermal fatigue dominates vibration damage by seven orders of magnitude. The board-level average of 62.9 flights is misleading: the ceramic PGA device D10 limits the unit to 12.3 flights (a preliminary model-based estimate, pending ALT calibration), a factor-of-five discrepancy, with three ceramic families (D10 PGA, D9 LCC, D6–D8 FIFO) forming the bottleneck. The combined weighting assigns 79.5% of the decision to the damage-derived criterion; Comprehensive Reusability Index (CRI) thresholds map flights 0–3 to direct reuse, 4–7 to refurbishment, and 8+ to retirement. The results distill into a weakest-link reuse principle, a damage-threshold service model, and an inverse-square thermal-fatigue relation.