The tree · Biology · World event · Mid: 5 to 20 years
A shielding system flown in space cuts the deep-space radiation dose to a crew by half
Beyond Earth's magnetic field, galactic cosmic rays deliver a dose that puts a multi-year mission near or past current career limits, and the heavy nuclei in that radiation are hard to stop with thin walls. Passive routes (thick water or hydrogen-rich walls, regolith) and active routes (superconducting magnetic shields) both exist on paper. A flown demonstration that halves the dose makes rotations of months at an outer site a matter of engineering rather than of accepting the risk.
What counts as it having happened
A shielding system flown beyond low Earth orbit is measured to reduce the dose from deep-space radiation (the galactic cosmic rays that Earth's magnetic field otherwise keeps out) at the crew position by fifty percent or more compared with an unshielded reference, reported in a peer-reviewed publication.
Settled by: The peer-reviewed flight measurement
Probability, by longevity scenario
| baseline2071 ± 8 | moderate2080 | strong2095 | radical2136 | openno deadline |
|---|---|---|---|---|
| 50% | 55% | 65% | 80% | 85% |
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: Thick water walls could do it today at a mass cost; halving the dose in a flown test within forty-five years is even odds because the passive route is expensive and the magnetic route waits on cheap superconductors.
Notes
The magnetic route depends on high-temperature superconductors at practical cost, an energy node; drawn at step 7.
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The record itself is data/B-biology.toml in the public repository.