The tree · Biology · World event · Mid: 5 to 20 years
A crew off Earth lives for a year with most of its food, water, and air recycled on site
The space station recycles most of its water and makes its oxygen from that water, but every calorie is shipped up. Ground experiments (a year-long sealed habitat in China) have closed the food loop on Earth. Doing it off Earth for a year is what partial self-sufficiency, the Tier 2 criterion, means in practice.
What counts as it having happened
A crew at a site off Earth completes twelve continuous months during which more than half of their calories are grown on site and more than ninety-five percent of water and oxygen are recycled, as reported by the operating agency or company.
Settled by: The operator's published life-support accounting
Probability, by longevity scenario
| baseline2071 ± 8 | moderate2080 | strong2095 | radical2136 | openno deadline |
|---|---|---|---|---|
| 50% | 58% | 70% | 85% | 90% |
Each number is the chance this resolves yes before that scenario's window closes, given that everything it depends on resolves first. Estimated 2026-09-08.
Why these numbers: Done on the ground for a year at 98 percent closure; doing it off Earth needs a site with the volume for farming, which is a settlement-scale project, so even odds by 2071.
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The record itself is data/B-biology.toml in the public repository.