Food-science shelf-life testing predicts quality loss with a first-order decay driven by a Q10 temperature coefficient — the standard accelerated-shelf-life-testing (ASLT) model used to certify real spaceflight food for NASA/ESA missions:
k(T) = k_ref · Q10^((T − T_ref)/10)
Q(t) = Q0 · e^(−k·t)
k is the quality-loss rate constant (per day), T_ref = 4°C is the reference locker temperature, and Q10 is how much the rate multiplies for every 10°C rise — moisture-driven spoilage (fresh food) is far more temperature-sensitive (Q10 ≈ 3) than the very low water-activity of freeze-dried and thermostabilized pouches (Q10 ≈ 2.2–2.5).
- Storage method — sets the reference decay rate k_ref: freeze-dried pouches lose water almost entirely, so their baseline k is tiny (shelf life of years); thermostabilized (retort-pouch) food keeps more moisture and decays faster; fresh/irradiated food decays fastest of all.
- Storage temperature — every simulated pouch shares the locker's temperature; raising it multiplies k through the Q10 term, exactly like leaving food out of a fridge.
- Seal integrity — a compromised vacuum seal lets in cabin humidity and oxygen, multiplying k by a fixed spoilage-acceleration factor regardless of method.
- Time to 50% quality — solved from the same exponential: t½ = ln(2) / k, the classic "shelf life" figure used on real ration labels.
Each pouch in the rack starts at a slightly randomised initial quality and decays independently, so the locker visibly turns from green to amber to red at different rates pouch-by-pouch — exactly the variability a real cargo resupply inventory shows.