EEVblog's Dave Jones critiques Reflect Orbital's plan to sell sunlight to solar farms after dark using orbital mirrors. He walks through the numbers to show the idea does not work out.
Why Hacker News points people here: HN cites it as a debunking whenever the space mirror startup comes up, as a TL;DW that the design is impractical.
This has long been debunked e.g. by Thunderf00t ( link ) and EEVblog ( this video ) It comes as no surprise this won't work when you imagine 1) where you have to put the mirrors: either in low orbit so as to keep light dispersion low and the apparent mirror size from the ground big—but now you have the problem that the mirrors move with high speed relative to the ground, and the time frame where you can still reflect light before entering into Earth's shadow is very short. Or you put them into a higher orbit so they can reflect light for a longer time, but now the light spot that arrives on the ground is even more dispersed 2) how big these mirrors can practically become, and how little light there will be when you have a, say, 100m² mirror hundreds or even thousands of kilometers away.
Criticalkspacewalk2Oct 2024
“Found a rather... skeptical take (I'd argue it's more of a takedown)[0].”
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Found a rather... skeptical take (I'd argue it's more of a takedown)[0]. A bit crazy how far off the math is from viability, for a company that someone actually invested money in. Impressive salesmanship though. [0] this video
CriticalsxpFeb 2025
“TL;DW: not practical in it's current design.”
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YT video going into the math and physics involved: this video TL;DW: not practical in it's current design.
Criticalreader9274Jul 2026
“Second, nothing would happen, the power will be minuscule and last for a very short time focused on such a small patch.”
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First, they don't exist and 10k of them will never exist. Second, nothing would happen, the power will be minuscule and last for a very short time focused on such a small patch. see: this video
