Emergency Reserve Drawdown (2D)

When a spacecraft's primary life-support loop fails, the crew doesn't fall back on infinite margin — they fall back on a finite stockpile of emergency oxygen, water and power that starts draining the moment the failure begins. This simulator models that drawdown in 2D: three live gauges shrink as O₂, water and power reserves are consumed at a rate set by crew size and an adjustable rationing level, a scrubbable depletion chart traces every reserve's fraction against mission time, and a supply-canister rack visualises the binding resource's remaining share, all tied to a live days-to-critical countdown. Push rationing harder and the countdown stretches — at the cost of comfort and safety margin — exactly the trade-off real mission controllers weigh when sizing contingency reserves for the ISS or a lunar transit.