California-based startup Reflect Orbital aims to build a swarm of 4,000 giant mirrors in low Earth orbit to “sell sunlight” to customers at night. Experts warn that the mirrors could mess with telescopes, blind stargazers and impact the environment.
Reflect Orbital, which was founded in 2021, has recently taken the first step in a scheme to sell sunlight at night by bouncing solar rays off giant “reflectors” that can redirect the vital resource almost anywhere on our planet. By doing this, the company aims to extend daylight hours in specific locations, thus allowing paying customers to generate solar power, grow crops and replace urban lighting.
But experts say it is a wildly impractical plan that should never get off the ground. What’s more, the resulting light pollution could devastate ground-based astronomy, distract aircraft pilots and even blind stargazers.
Your point about poinitng (ha!) is incorrect, its pretty trivial to maintain pointing at the target. Hubble achived 7mas pointing accuracy over extended periods (thats ~0.000002degrees) with technology more than 30 years out of date. That gives you ~1.2m accuracy from geostationary orbit, which seems fine.
The real point is getting a mirror which is large enough and perfect enough into orbit is completely infeasible. As you rightly say, the maximum potential power it can provide is equal to solar insolation time its area.
The aiming is still a problem. The Hubble is relatively small. Even then, it can’t track fast enough to image the moon, let alone the earth’s surface.
Any useful reflector would be measured in Km^2 . Aiming that, with the same precision as Hubble would be a tall order. Added to that, the mirror would have to be light enough to launch. You’re basically trying to aim a sheet of tinfoil, as large as a stadium (minimum), with active tracking.
The Hubble is also in a rather low Earth orbit (340-ish miles), which enables it to use magnetic brakes which allow it to ditch the excess energy from its reaction wheels into the Earth’s magnetic field so it can stop pivoting when it aims. The further away you get from the planet the less effective that becomes. The bigger your object is, the bigger your reaction mass needs to be.
And the Hubble doesn’t inherently roast or blind innocent bystanders as it swings its point of aim across all of the intervening space between its targets. Maintaining a steady shine on one particular point on the surface is one thing, but these idiots seem to be implying that they will sell sunlight-as-a-service via some kind of subscription model to multiple customers, so they would presumably be changing targets all the time.
The amount of time it takes for the Hubble to get on a target is broadly irrelevant, only that it can keep itself there once it eventually achieves targeting. This would not be so with the hypothetical solar reflectors, regardless of what altitude they were flown at.