Mass test only. Count only product the site would otherwise ship in; output beyond that is export, not closure. Plant and product travel the same corridor, so the launch gear ratio cancels out of the ratio; it matters for cost, which the Δv corridor calculator gives. 0.37 t/kWe is the lunar outpost's generation, storage, distribution and rejection divided by its 150 kWe.
Below 1× the plant never returns its own landed mass and shipping the product wins on mass. Between 1× and about 3× the answer turns on plant life, reliability and spares. Above about 10× making it locally wins even at poor yields. When the mass test fails, the case rests on schedule - the wait for a shipped replacement, the design loop and self-expansion - as The Machine Shop MVP shows.
Plant wear and spares, qualification of the product, crew hours, and the fact that the rungs share one power bus and run in campaigns - see one bus. The water presets rest on one ice measurement, LCROSS at Cabeus in 2009; CNSA's Chang'e-7 and Chang'e-8, the first missions built to measure polar ice and demonstrate extraction on site, will move them. Metals reduction has no derived plant mass anywhere in the analysis; 20 t is a placeholder. At 100 t a year it passes only if somebody else buys the metal - it is an export rung, not a closure rung.
| Rung | Hardware | kWh/kg | Rate | Closure ratio | Rated |
|---|---|---|---|---|---|
| Salvage | 0.2 t | 1.0 incl. handling | 45 t/yr | About 22 per year | Modeled |
| Water, 5 wt% | 12 t | 5.0 | 100 t/yr | 3.0 per year | Modeled |
| Water, 1 wt% | 12 t | 10 | 100 t/yr | 1.9 per year | Modeled |
| Oxygen | 10 t | 7.0 | 100 t/yr | 2.5 per year | Modeled |
| Structure, forming | 1.1 t | 3.7 | 25 t/yr | About 5 per year | Modeled |
| Spares, machining | 3.1 t | 78 | 0.75 t/yr | 0.13 per year | Modeled |
| Metals reduction | 20 t (assumed) | 30 | 0.4 t/yr site demand | 0.02 per year | Modeled |
From Closure Sequencing, Revision C (August 2026), and The Substrate Tables. Closure ratio = annual product ÷ (plant + 0.37 t/kWe × average power).