A spacecraft beams at least a kilowatt of power to a receiver on the ground

Space-based solar power, if it ever pays, is a reason to build very large things in orbit and to have people maintaining them. Small demonstrations have transmitted watts. A kilowatt received on the ground is the step that makes the engineering argument real, and several agencies plan demonstrations within a few years.

The test: what counts as it having happened

A spacecraft in orbit transmits power to a receiver on Earth's surface that delivers at least one kilowatt of net electrical output attributable to the transmission, sustained for ten continuous minutes, with calibrated measurements, reported in a peer-reviewed publication or an agency mission record.

Settled by: The peer-reviewed publication or the agency's mission record

The odds, by how long I live

baselineto 2071 ± 8	moderateto 2080	strongto 2095	radicalto 2136	openno deadline
45%	55%	65%	78%	82%

Each column is a different guess at how long I live, from current trends (baseline) to open-ended. The number is the chance this happens before that deadline, assuming everything it depends on happens first. As of September 19th, 2026.

Why these numbers: The only orbital demonstration so far (2023) beamed milliwatts, agency kilowatt demonstrations have slipped repeatedly, a received kilowatt needs an aperture nobody has funded, and ground solar with storage undercuts the business case; a little under even by 2071.

What this one is worth

Nothing. The headline number does not rest on this step at any remove, so however it turns out, the chance that I live and work off Earth does not change. That is not a judgement that it does not matter. It is what the tree says: this step feeds a tier above the one the headline asks about, or sits beside the equation rather than in it.

What the ledger says about this step

A kilowatt beamed from orbit to the ground came down: the one demonstration so far was milliwatts, and the business case may never justify the aperture 2026-09-20 Changed my mind

The last 3 checks

Once a week the tree is read against the news, node by node, against the test above. Open a line to see what that week held. Every check ever made on this node is on the Radar page.

2026-11-01 Nothing new

No orbit-to-ground kilowatt result was found, only planned demonstrations (Aetherflux, Virtus Solis, Overview Energy for 2027 or 2028) and the earlier Caltech milliwatt result. Plans are not the event.
2026-10-25 Nothing new

No spacecraft has beamed a kilowatt to the ground in a published record. Aetherflux's kilowatt-class demonstration was planned for 2026 and no launch or result was found; Overview Energy's demonstration is set for 2028.
2026-10-18 Nothing new

No orbit-to-ground kilowatt demonstration has been reported. Aetherflux's demonstration and Japan's OHISAMA satellite were both planned for 2026 and neither showed a launch or measured result in the search results.

Revisions

Date	Field	From	To	Why
2026-09-19	resolution	'delivers at least one kilowatt', no duration	at least one kilowatt of net electrical output attributable to the transmission at the ground receiver, sustained ten continuous minutes, with calibrated measurements	Step 27 outside-model review, item 83 (docs/reviews/2026-09-19-rulings.md): a momentary peak during a pass could otherwise have counted. Decided September 19th, 2026.
2026-09-19	probability	0.75 / 0.85 / 0.92 / 0.95 / 0.96	0.45 / 0.55 / 0.65 / 0.78 / 0.82	Step 27 outside-model review, item 26 (docs/reviews/2026-09-19-rulings.md): the first estimate assumed agency demonstrations that keep slipping, and the 2023 flight was milliwatts (verified); Gemini argued a large cut and Astra left the number alone, so moved partway. Decided September 19th, 2026.

Think this estimate is wrong? Here's how to tell me, and what happens next. The record itself is data/M-motive.toml in the public repository.