Posted by reaperducer 4 hours ago
https://www.pcmag.com/news/fcc-approves-reflect-orbitals-gia...
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.
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.
Given most people don't have any reason to illuminate several square kilometres at once, for realistic scenarios it will take a lot of satellites before you beat the cheap battery-powered floodlights in my local Aldi or Kaufland, and the batteries in those lasts a lot longer than the 10-15 or so minutes each of the satellites will be over the horizon, and reflectors like these can only supply sunlight close to sunset otherwise the earth blocks the sun from them.
In the list of things which, if you could make them at all useful, would also be 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.
I thought this was interesting because it doesn’t really seem like an applicable top level claim, surely this is referring to a specific furnace, not all solar furnaces?
Then this got me thinking if there is some universal upper bound constraint to these temperatures. E.g. if I recall a telescope can’t make a source object brighter than it actually is, and this just seems like a thermal telescope, so I wonder if that principle applies here or not.
It applies, but also in practice the maximum temperature is lower than the theoretical upper bound.
Obviously this satellite isn't viable, but all things start small. Large tracts of land could be illuminated.
But of course, I question the logic of redirecting more sunlight, especially such large amounts, onto a world already warming uncontrollably.
Still, it could be useful for the polar caps on Mars?
These seem like unlikely things though.
That said, I'm (armchair) confident it'll be good for moonlight-level illumination on a local area at best. They'll need to scale up to thousands / tens of thousands to make any measurable impact - which is their objective by the looks of it, but it'll take a while yet. If this one creates enough backlash, a fleet won't make it. Assuming they get the money and customers to justify a fleet in the first place.
What might be more useful is to illuminate just the areas where a human currently needs to see well. It would hypothetically be both more useful - you can concentrate more light in just the areas you need it - and less expensive.
What would be particularly cool about this hypothetical technology is that it could work equally well under foliage and indoors.
My guess is it's probably easier to make a bunch of greenhouses on the surface? But the scale is so huge that which is best will be affected by technology invented after you start.
X Wing: Wedge’s Gamble (1996) by Michael Stackpole shows the rebel alliance using similar tricks during the battle of Coruscant.
I'm far more concerned about the people who own/build stuff like this using it as you suggest (or any of the government pets that they own) than I am about "hackers" doin' such things (although, you're entirely right to have that concern as well, because there's obviously those type of folks out there doin' bad things even with the technology we have already).
50000 60-ft mirrors is about the same area as a single mirror 2.5 miles across. So the area of the mirrors is about the area of a city. You gather as much light as the city itself in regular daytime. If you focused all of that perfectly efficiently onto a city, that city would just look like daytime.
Then again, assuming there's no dispersion or loss, 50.000 times the sun focused on a 60ft patch will likely have some impact. But that's complete fiction.
This strikes me as another hand-waved scifi/fantasy inspired investment, where everyone is so caught up in proving they can achieve this (spoiler: this is obviously possible) that no one has stopped to ask does that achievement lead to a real benefit outside of VC wealth transference?
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 aimed at a specific point for long enough to achieve significant heating. I wouldn’t be surprised if it’s difficult to achieve an increase in heating that’s close to, say, the heating difference from standing outside at noon as opposed to 5PM. Which then doesn’t do much because you couldn’t effectively use a reflector at noon, anyway. You’d want a lens instead. Or some sort of complicated Newtonian telescope type contraption.
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.
And a satellite isn't going to provide "hours" of extra light unless it's a very much higher orbit than current proposals. At 600 km altitude, you're talking 20-30 minutes even with an unbounded number of satellites (and 10-15 minutes when you've only got a few satellites). Same reason as sunset itself happens: Earth just gets in the way.
If this is somehow an actual problem, it is far more solvable with tethered blimps or drones, battery pack in a container on a truck, a spool of wire, and light banks as big as you want. AND that isn't subject to clouds (but would be subject to high winds, which would also be more likely to cancel/postpone the event than clouds).
Meanwhile, they go beyond the already massive disturbance of existing terrestrial lighting and overwhelmingly screw up the biologically critical light signals used by every plant, insect, animal, and human in the zone, and do it at multi-kilometer scale.
Edit: Even if the revenue potential is actually huge, it is no justification. For any intelligent person, the actual sponsorship message will be "Tonight's lighting brought to you by [Insert_Company_From_Which_I_Will_Never_Buy_Anything_Again]
This level of stupidity is beyond evil — the kind of lunacy to make a good argument that humans should not exist.
I saw a presentation by one of the founders where he talked about several use cases where the benefit is just phenomenal.
They don't fool me for a second, however. The end goal of this is to build a weapon that can fry people/places on demand (but only the bad guys, of course).
The military application would just be illumination.
I'm sure that's attainable with a few hundred sats.
Can someone do the math?
The FCC only approved that the satellite would not interfere with other radio communications, not the ultimate purpose. They said themselves they don't have authority for that.
It sounds too coarse-grade in terms of its area to be anything other than disruptive socially and ecologically.
Sporting and cultural events? Not really (extending the hours of sunlight over a city does have marginal value for a major celebratory event I suppose, but there just aren't that many of these).
Farming? Don't plants need night too? Does harvesting need the sun anymore?
But being able to illuminate a war zone with spontaneous sunlight you can switch off at will, that is a weapon, not least because if you are the only one with the power, your opponents will have to act knowing they may not have the cover of night.
It's not as dangerous as allowing Elon Musk to launch so many more satellites that he ends up with de facto control over access to earth orbit, but it's pretty dangerous.
I think so, but even then it's a heck of a lot of work to make it useful for that.
> Farming? Don't plants need night too? Does harvesting need the sun anymore?
Mostly limited by other things, hence why there's only limited farming in the Sahara, relatively little phytoplankton in the North Atlantic Gyre.
> But being able to illuminate a war zone with spontaneous sunlight you can switch off at will, that is a weapon, not least because if you are the only one with the power, your opponents will have to act knowing they may not have the cover of night.
Even then, nah. Militaries have had night vision for ages. We can make a wall-penetrating radar work as heartbeat/breathing sensor out of kit fairly close to (but not close enough to be a software patch from) a WiFi base station.
I just don't really get it.
And as this is optical, won't go through clouds. This is why beamed power discussions often talk about converting to microwaves instead, though that comes with an even bigger spot size on the ground.
It's not going to be full daylight, is it?