ECLSS Spares Provisioning: MTBF-Driven Cost Model

Life-support hardware doesn't fail on a schedule — it fails as a random process with a known average rate, and every spare part launched to cover that randomness costs real money to lift off Earth. This simulator sizes a spare-parts cache for five real ECLSS line items (CO₂ scrubber, water processor, oxygen generator, cabin fan, coolant pump) from each one's mean time between failures, using a Poisson reliability target rather than a guess. Set the mission duration, crew size, target reliability, and launch cost per kilogram, and watch the 3D cargo racks resize to the resulting spares count and total launch cost. Press Simulate to run an actual stochastic mission clock — failures are drawn live from each component's Poisson process and consume real crates from the racks, so a cache sized too thin visibly runs out before the racks refill.