A spacecraft's life-support systems never fail one at a time in a convenient order — the CO2 scrubber, O2 generator, water recovery loop and thermal control loop all drift independently, and a mission-ops team needs a principled way to decide which one to service first. This simulator runs a real decision-support pipeline on four simulated ECLSS subsystems: an exponentially-weighted moving average smooths each subsystem's noisy stress-index telemetry, a control-chart z-score flags statistical anomalies, a smoothed trend slope extrapolates a Remaining-Useful-Life estimate to the failure threshold, and a weighted decision matrix combines anomaly severity, RUL urgency and fixed mission-criticality into a single ranked priority list — exactly the class of statistical-process-control-plus-RUL system real ECLSS operations use. Drag the decision-weighting slider to see the recommended action flip between "it's acting weird" and "it's about to run out of margin," or inject a random fault and watch the 3D habitat ring's module color and the ranking update live.