Space Cabin CO2 Exposure-Limit Comparator (2D)

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 2D build renders that mass balance as three linked panels: a rotatable cabin cutaway whose fill level and drifting particle density track live concentration, a strip chart plotting ppm against simulated mission time, and a bank of comparison bars that measure the current 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.