Space Cabin CO2 Exposure-Limit Comparator

Every crewed spacecraft is a sealed box slowly filling with the CO2 its own crew exhales, held in check by a scrubber like the ISS's CDRA. This simulator integrates that mass balance in real time — set crew size, scrubber efficiency and mission-clock speed and watch a 3D cabin gauge fill with particle density as concentration rises — then checks the live level against three real regulatory thresholds side by side: the permissive Shuttle-era limit, NASA's current 7-day Spacecraft Maximum Allowable Concentration, and the tighter limit proposed after research linked elevated CO2 to measurable cognitive impairment. The same mission profile can be compliant under one standard and already in violation of another, which is exactly the harmonization problem regulators across agencies are still working through.