Live data from Hacker News

FCC approves test of space mirror to light night sky

theconversation.com

81–90 of 164 posts

Re: FCC approves test of space mirror to light night sky

#84
post #72

Earlier quoted context omitted.

Except if the reflectors are shaped for wide area illumination, then their focal distance is probably nowhere near the distance from the satellites to the earth’s surface. So I don’t think is any “single point” to be had. Heck, I haven’t done the math or anything but I bet even if you did instead use parabolic reflectors that were tuned to focus at the earth’s surface, it would still be very difficult to keep them ai…

I don't think these things start out looking like a weapons. Wrong reflector shape? It could just be proving out other aspects. It could also be completely innocent too, but I don't think this is quite conspiracy level thinking.

> It could just be proving out other aspects. It could also be completely innocent too, but I don't think this is quite conspiracy level thinking.

This honestly strikes me as an innocent test of one random idea/technology. The whole "conspiracy level" thing (if it were to ever happen at all) would come later on, and most likely from entirely different people usin' the things discovered from experiments like this one in wholly unacceptable ways because they simply have too much power, money, and time, and not nearly enough good sense between their ears.

Sad though that as other folk have pointed out, if the technology were to work as expected, then it could also be used to help mitigate global warming by reflecting a specific amount of sunlight away from Earth, too. The sad part is that's likely not what such experiments will lead to initially. The "bad people" tend to be pretty quick to try to weaponize or monetize (or both) anything they take an interest in.

Re: FCC approves test of space mirror to light night sky

#85
post #54

So we've got this problem of the atmosphere trapping too much heat from solar radiation hitting the surface and the plan is to increase the amount of solar radiation hitting the surface?

It's fine just setup mirrors on the ground to bounce the light back to the satellite! (/s)

it'll be great for the GDP, too!

Re: FCC approves test of space mirror to light night sky

#86
post #10

They seem to be talking about each satellite managing the luminosity of the full moon over a few square kilometres, and getting a few tens of thousands of them. Even if you ignoring how much drag these must have, and hence how much electrical power you'd need for an ion drive just to keep them up, each spot being a few km across (and only getting light while the satellite is over your horizon) is just not compelling.…

> relatively easy to redesign as weapons There is a fiction I've read years ago that mentioned satellites becoming makeshift weapons by overheating exposed objects (think reactors, gas trucks, oil refineries) by acting as a solar furnace [1] via mirrors. Not sure/don't recall how it deals with practical issues such as clouds and distance/intensity, but good enough for a story I guess. [1]: https://en.wikipedia.org/wi…

You can't focus sunlight at the satellite distances. And this is a fundamental problem, the focal distance varies for each wavelength so your focus point will be smeared. You need monochromatic light for that (a laser).

Edit: and also don't forget that the Sun is not a point source and has an appreciable angular size, further making it impossible to focus it with a reasonably-sized lens or mirror.

Re: FCC approves test of space mirror to light night sky

#87
Earth orbits, low orbits above all, are a finite resource, and suffer pollution as every environment, with all this kind of satellites growing in number to millions, things can go badly: https://en.wikipedia.org/wiki/Kessler_syndrome

Apart tecnical and scientific reasons (no need to use thousand or million of sats), apart big speculations (suspect is the main reason), many problems can be resolved in others ways.

Re: FCC approves test of space mirror to light night sky

#90
post #25
post #10

They seem to be talking about each satellite managing the luminosity of the full moon over a few square kilometres, and getting a few tens of thousands of them. Even if you ignoring how much drag these must have, and hence how much electrical power you'd need for an ion drive just to keep them up, each spot being a few km across (and only getting light while the satellite is over your horizon) is just not compelling.…

With global warming, trillions upon trillions of acres of immensely fertile bogland, in Northern Canada is thawing. The problem is, global warming doesn't affect daylight. 4 hours of "the sun barely makes it over the horizon" means no crops, no matter if the temp is above 0C in September. Obviously this satellite isn't viable, but all things start small. Large tracts of land could be illuminated. But of course, I que…

> The problem is, global warming doesn't affect daylight.

In my book, that would have been a "Fortunately," entry.

Post reply on HN