Closed-Loop Life Support Sustainability Index (2D)

A crewed spacecraft or habitat cannot resupply water, air and consumables from Earth indefinitely — long-duration missions live or die on how completely their life-support loops close. This 2D companion simulator models the same three independent recycling loops (water, oxygen/CO₂, solid waste) with real per-crew consumption rates, computes an overall sustainability index and the annual resupply mass those loops still leak, and renders the loops as flat orbiting particle rings: watch the fraction that turns red and breaks away to the resupply pod shrink dramatically as you push each loop's closure toward the high 90s, exactly the nonlinear trade-off that governs real ECLSS design.