The tree · Drive · World event · Root: on the scale of the whole window
Nuclear propulsion is used on several missions a year
The Tier 3 criterion in propulsion terms. One demonstration proves it can be done; several missions a year means it is the ordinary way to move heavy things around the inner solar system, which is what transit times of months to the Belt assume.
What counts as it having happened
In one calendar year, at least three separate missions beyond low Earth orbit use nuclear-powered propulsion for their main transfer, confirmed by the operators and independent tracking.
Settled by: Operators' mission records and independent tracking
Probability, by longevity scenario
| baseline2071 ± 8 | moderate2080 | strong2095 | radical2136 | openno deadline |
|---|---|---|---|---|
| 50% | 60% | 75% | 88% | 92% |
Each number is the chance this resolves yes before that scenario's window closes, given that everything it depends on resolves first. Estimated 2026-09-19.
Why these numbers: One demonstration to routine use is the gap the space station took two decades to cross; a Mars cadence would pull it forward.
Think this node is wrong, missing a dependency, or estimated badly?
Open an issue about it, or read
how critique gets folded into the tree.
The record itself is data/D-drive.toml in the public repository.