One question I have is about apparent magnitude: given the satellite's small size (relative to the apparent size of the moon) it would have to be very bright to match the luminosity of the full moon on the surface.
> calculated that the Reflect Orbital spacecraft would appear as points of light with a magnitude of -15 [...] might damage the eye.
-15 seems ~10 times brighter than the moon (-12,6) if I got the formula right so it would indeed be very bright.
Reminds me of all the led lighting we have now: one evening on a random street I watched the cars, bicycles, shops, street lamps: all leds, yes a bit brighter and colder than the old bulbs I know, buuut the light sources being very small dots (with no diffuser), it feels very harsh to the eye, at least to me.
Anyway, even if it proves useful for something, it would join the long list of innovations doing one thing at the expense of everyone else (externality == light pollution in this case).
> Anyway, even if it proves useful for something, it would join the long list of innovations doing one thing at the expense of everyone else (externality == light pollution in this case).
That's a strange reading. What would keep the benefits from cheaper electricity from diffusing to roughly everyone, as they usually do?
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.
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.
> The temperature at the focal point may reach 3,500 °C
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.
Oh funny, my intuition when I was writing that was “there’s probably an xkcd what if about this”, but I imagined it be about surrounding the sun with mirrors. Same idea though in the end
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.
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 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?
If sattelites can reflect enough light to make an impact on e.g. global warming, they can also reflect enough to circumvent it. Point them back at the sun or into space and in theory it redirects the same amount of energy away from the earth as it would pointing towards it.
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.
Though I have to ask the value of illuminating large tracts of mostly uninhabited land. Lighting areas where no humans are around to want the light seems like a proposition that’s mostly useful for further disturbing nocturnal wildlife.
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.
Mars… needs something rather bigger. I don't know what the most cost-effective solution would be, but Mars gets about half the per-area sunlight as Earth so it would need a reflector about the size of Mars to get the same overall insolation.
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.
In regards to people with reasons to illuminate several sq km at once - I'd bet that major metro areas would see a massive savings in electricity/maintenance if these were deployed over a metro region. Whether that is more than the cost of a satellite? Who knows, it's still fiction until these people try it out. But it's at least an interesting use case.
> There are many problems with this proposal, including impacts these satellites will have on human health and safety, as well as on astronomy and the low-Earth environment.
> Flashes during mirror repointing could disrupt pilots and drivers. The light could also disrupt circadian rhythms of plants, animals and humans
Wonder what would happen if a hacker focused all ten thousand of them on a single area for an hour or two. Sounds like a really energy-efficient way to demolish a city.
X Wing: Wedge’s Gamble (1996) by Michael Stackpole shows the rebel alliance using similar tricks during the battle of Coruscant.
> "Wonder what would happen if a hacker focused all ten thousand of them on a single area for an hour or two. Sounds like a really energy-efficient way to demolish a city."
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).
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.
I don't think 50000 60-ft mirrors at the height they intend to fly would cause that to happen. Not enough light gathering power.
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.
I think what you're missing is that they could all be focused in one spot, not spread over the city. If curved reflective buildings can melt siding, and mirror solar plants can melt salt, I'm pretty sure a city's worth of sun focused on, say, a college campus, could start a massive fire
I think people overestimate the relative strength of the sun.
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.
How are the economics of this idea meant to be viable? The proposed business model is to park hundreds of millions to billion dollars of satellites in orbit, plus the costs to maintain and operate them, to meet the goal of selective area illumination and solar power. Ignoring the issue of cloud cover, which still seems to be an impediment. That's going to need to directly compete with terrestrial energy storage technology, e.g. batteries, and... general lighting. Both of which are well established, diversified and reliable market segments with vastly cheaper MWh costs compared to beaming a small amount of light down using a satellite.
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?
Such as? Military in the next 100 years will be drone / remote based, they have IR / night vision and soon to be fully automated. Sunlight can be handy for humans but for decades now the only ones that would benefit from it would be foot soldiers, and they're like the last resort (for western forces anyway).
Daylight helps you just as much as your enemy. We've got plenty of cutting edge night vision and thermal imaging devices for humans and radar on vehicles. The Army's 160th helicopter regiment can fly nap of the earth on a moonless night. Satellite-based Synthetic Aperture Radar can pickup human sized objects during a pass and can switch to sub-centimeter resolution in finer modes. If anything, the military prefers fighting at night because of the advantage it holds.
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 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.
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.
The revenue potential is huge. Think of public events where people might want to illuminate the area as daylight for several hours. Galas, sports, concerts, parties, etc.. They will all pay top dollar and they have the funds. Could get sponsors, "Today's sunlight brought to you by NordVPN"
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.
Opposed to holding the event during the earth's orientation towards the sun, aka daytime? Someone should tell the gala and event organizers about this idea of daytime.
How huge is it on a continuous basis? Ii's low earth orbit, so only available for a few hours after sunset, AND requires a new satellite in position every 15 min. So for two hours extra illumination you need to support a couple DOZEN satellites, costs of build, launch, control, and maintenance. Even with 100% bookings —every night— it is dubious finances. Seems much more like a scheme to generate a money flow from meme-investors they can siphon off into their pockets then oops, it fails.
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).
orbital mirrors make very poor weapons because Conservation of Etendue means you fundamentally cannot concentrate very high unless your fill factor is very high (which would require millions of tons in orbit). Lasers are far more effective as weapons as a single aperture launched on a single rocket is sufficient to get high concentration. Microwaves also.
The military application would just be illumination.
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?
This is a terrible idea. Light cycles affect many natural functions in the world. We already see some of this with light pollution. This idea is basically light pollution on an industrial scale.
> The FCC said that the “risks of harm raised on the record regarding Reflect Orbital’s solar reflector are unrelated to the Commission’s role in authorizing use of radiofrequency spectrum.”
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.
The only non-marginal application for this is military, surely.
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.
> The only non-marginal application for this is military, surely.
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 guess it has policing applications, marginally. But most police forces just use helicopters and night vision, and ultimately rely on the disruptive sound of the helicopter to bring people out to look for whoever they are chasing; the noise of a helicopter makes people vigilant.
At the orbits they're talking about, at best 30 minutes before dawn and after sunset. Earth gets in the way, have to go much much higher to get 24 hour coverage, and if you can focus that well over that distance you've got the optics for a super-weapon.
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.
Obvs "MaaS" capitalisation for the full stock valuation.
Obvs(2) a variant of this service has traditionally been provided for free by drunken teens. They might prove to be better and more thoughtful custodians of investment funds.
Someone tried to recruit me back in 2000 for a startup that would sell a box you connect to your computer allowing you to smell things over the internet. I'll let you guess what industry he was targeting.
2014 was the inflection point. 2013 brought us the term unicorn for companies, and was just long enough after the iphone that we were starting to make sense of it. That's when Elon Musk became a household name thanks to Tesla and SpaceX. Then there was Palantir. Google bought Deepmind in 2014. Google Facebook Amazon and Apple showed founders that software startups could transform the world, and the world leapt at the chance.
The fact that they're spelling this Earendil, not Earendel, makes me think this is a direct reference to Tolkien's work. It's pretty weird for dystopian industrial initiatives to be named after characters in a work whose most unambiguous message was that rampant industrialization was ruining the world.
Sounds like a morning star reference (via some obscure Christian texts) which I will draw further towards Lucifer via Latin. Do with this idea as you please.
It's actually more'n a little bit scary how much of modern "politics" seems as if it could be driven by having watched any of a number of movies and thinking "We should do that!" When I hear people talk about politicians bein' like spoiled brat children in adult bodies, I tend to think that sounds like exactly the type of mentality that could see something all messed up and scary in a movie and want to try to do it in the real world. What makes it even more scary in my mind is that we've allowed those type of people to gather entirely too much money and power such that they have the option available to them to seriously consider trying such horrible ideas.
Annoyingly and predictably, reads like AI slop. You can practically guess the prompt goes something along the lines of 'write a press release explaining why this bad idea is a good idea'.
I swear this is getting so common. “Well I’d be fine with eugenics and sterilization of the poor, but the website uses em-dashes a lot so I think it’s just awful AI slop”.
(Why, of all the things, would someone use a fire as their example for this? Fire is famously a light source. Also, famously, smoke is a thing that blocks out light from above).
Launching a gossamer thin mirror in space is not very expensive. Broad strokes claiming anything launched to space is going to be a more expensive solution has to level with the fact that GPS and quite a lot of telecommunications and Earth observation seem to have incredible leverage if launched to space instead of just using ground based solutions.
For this use, "gossamer thin" is unlikely. You want to control where you point the mirror, it needs a structure that not only doesn't flop around when you torque your spacecraft, but also doesn't have surprise vibrational modes that squeeze and expand the illumination zone.
(Things I'm learning while researching what is now looking like an eight thousand or more word blog post about why a different space thing, data centres, is also not a good investment; my guess is this would be less of a problem if you used mirrors like this to cool the earth by reflecting sunlight away instead of towards).
I initially quite liked it, particularly when the references are a bit more obscure, generally from classic scifi/fantasy. You can end with a nice sounding name and a small wink to fellow nerds.
But it is such a shame that it has started to become the brand of dark-side (militaristic/authoritarian) Silicon Valley: Palantir, Anduril, this… Tolkien would be so very sad.
PS: Palantir is at least rather fitting and honest, it’s literally an evil crystal ball (at least the one shown in the movies).
Chinese outcry? There’s a lot of that in social media, their bot warriors are everywhere. Same with AI and anything that gives the USA competitive edge.
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.
putting mirrors in orbit to have (little) more light is like buiding city underwater to have more cool. ops this last will be way less stupid in the future...
To downvote a different opinion without arguing is same kind of attitude: stay fresh.
One question I have is about apparent magnitude: given the satellite's small size (relative to the apparent size of the moon) it would have to be very bright to match the luminosity of the full moon on the surface.
In this article: https://skyandtelescope.org/astronomy-news/new-kind-of-satel...
> calculated that the Reflect Orbital spacecraft would appear as points of light with a magnitude of -15 [...] might damage the eye.
-15 seems ~10 times brighter than the moon (-12,6) if I got the formula right so it would indeed be very bright.
Reminds me of all the led lighting we have now: one evening on a random street I watched the cars, bicycles, shops, street lamps: all leds, yes a bit brighter and colder than the old bulbs I know, buuut the light sources being very small dots (with no diffuser), it feels very harsh to the eye, at least to me.
Anyway, even if it proves useful for something, it would join the long list of innovations doing one thing at the expense of everyone else (externality == light pollution in this case).
> Anyway, even if it proves useful for something, it would join the long list of innovations doing one thing at the expense of everyone else (externality == light pollution in this case).
That's a strange reading. What would keep the benefits from cheaper electricity from diffusing to roughly everyone, as they usually do?
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.
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.
> 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/wiki/Solar_furnace
Probably easier to use a MASER
> The temperature at the focal point may reach 3,500 °C
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.
> 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.
https://what-if.xkcd.com/145/
Oh funny, my intuition when I was writing that was “there’s probably an xkcd what if about this”, but I imagined it be about surrounding the sun with mirrors. Same idea though in the end
You may have been thinking of this one instead https://what-if.xkcd.com/141/ . Maybe we should put Randall on the supervillain watchlist.
007: Die Another Day has it as a main plot point.
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.
This has pretty obvious military applications in addition to the "solar all day" application.
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 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.
If sattelites can reflect enough light to make an impact on e.g. global warming, they can also reflect enough to circumvent it. Point them back at the sun or into space and in theory it redirects the same amount of energy away from the earth as it would pointing towards it.
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.
Though I have to ask the value of illuminating large tracts of mostly uninhabited land. Lighting areas where no humans are around to want the light seems like a proposition that’s mostly useful for further disturbing nocturnal wildlife.
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.
Mars… needs something rather bigger. I don't know what the most cost-effective solution would be, but Mars gets about half the per-area sunlight as Earth so it would need a reflector about the size of Mars to get the same overall insolation.
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.
> The problem is, global warming doesn't affect daylight.
In my book, that would have been a "Fortunately," entry.
In regards to people with reasons to illuminate several sq km at once - I'd bet that major metro areas would see a massive savings in electricity/maintenance if these were deployed over a metro region. Whether that is more than the cost of a satellite? Who knows, it's still fiction until these people try it out. But it's at least an interesting use case.
> There are many problems with this proposal, including impacts these satellites will have on human health and safety, as well as on astronomy and the low-Earth environment.
> Flashes during mirror repointing could disrupt pilots and drivers. The light could also disrupt circadian rhythms of plants, animals and humans
Wonder what would happen if a hacker focused all ten thousand of them on a single area for an hour or two. Sounds like a really energy-efficient way to demolish a city.
X Wing: Wedge’s Gamble (1996) by Michael Stackpole shows the rebel alliance using similar tricks during the battle of Coruscant.
> "Wonder what would happen if a hacker focused all ten thousand of them on a single area for an hour or two. Sounds like a really energy-efficient way to demolish a city."
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).
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: https://youtu.be/lkjyeI0ykGM
At some point, nations are going to claim the orbital space above them as national territory and develop technology to shoot down violators.
Die Another Day (2003) has a more ridiculous take on the same idea.
I don't think 50000 60-ft mirrors at the height they intend to fly would cause that to happen. Not enough light gathering power.
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.
I think what you're missing is that they could all be focused in one spot, not spread over the city. If curved reflective buildings can melt siding, and mirror solar plants can melt salt, I'm pretty sure a city's worth of sun focused on, say, a college campus, could start a massive fire
I think people overestimate the relative strength of the sun.
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.
How are the economics of this idea meant to be viable? The proposed business model is to park hundreds of millions to billion dollars of satellites in orbit, plus the costs to maintain and operate them, to meet the goal of selective area illumination and solar power. Ignoring the issue of cloud cover, which still seems to be an impediment. That's going to need to directly compete with terrestrial energy storage technology, e.g. batteries, and... general lighting. Both of which are well established, diversified and reliable market segments with vastly cheaper MWh costs compared to beaming a small amount of light down using a satellite.
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?
Think of the military benefits.
Such as? Military in the next 100 years will be drone / remote based, they have IR / night vision and soon to be fully automated. Sunlight can be handy for humans but for decades now the only ones that would benefit from it would be foot soldiers, and they're like the last resort (for western forces anyway).
Daylight helps you just as much as your enemy. We've got plenty of cutting edge night vision and thermal imaging devices for humans and radar on vehicles. The Army's 160th helicopter regiment can fly nap of the earth on a moonless night. Satellite-based Synthetic Aperture Radar can pickup human sized objects during a pass and can switch to sub-centimeter resolution in finer modes. If anything, the military prefers fighting at night because of the advantage it holds.
Yes, think about how this can be weaponized. Illuminate an area? Or, focus that energy on a single point and you've got sun powered space lasers?
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 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.
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.
The revenue potential is huge. Think of public events where people might want to illuminate the area as daylight for several hours. Galas, sports, concerts, parties, etc.. They will all pay top dollar and they have the funds. Could get sponsors, "Today's sunlight brought to you by NordVPN"
Here's a ninety thousand lumen floodlight: https://www.kaufland.de/product/500729350/?search_value=stad...
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.
But they'd be competing with the old fashioned stadium lights. I don't think they would be cheaper somehow.
Opposed to holding the event during the earth's orientation towards the sun, aka daytime? Someone should tell the gala and event organizers about this idea of daytime.
How huge is it on a continuous basis? Ii's low earth orbit, so only available for a few hours after sunset, AND requires a new satellite in position every 15 min. So for two hours extra illumination you need to support a couple DOZEN satellites, costs of build, launch, control, and maintenance. Even with 100% bookings —every night— it is dubious finances. Seems much more like a scheme to generate a money flow from meme-investors they can siphon off into their pockets then oops, it fails.
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.
Frankly I don't see this happening before the year of the Depend Adult Undergarment
Rescue operations, etc...
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).
orbital mirrors make very poor weapons because Conservation of Etendue means you fundamentally cannot concentrate very high unless your fill factor is very high (which would require millions of tons in orbit). Lasers are far more effective as weapons as a single aperture launched on a single rocket is sufficient to get high concentration. Microwaves also.
The military application would just be illumination.
You don't need to go "very high", 80C is more than enough to wreak havoc.
I'm sure that's attainable with a few hundred sats.
Can someone do the math?
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)
You jest but if one sattelite can be used to focus light onto the earth, it can also be used to focus it away from it, evening it out.
it'll be great for the GDP, too!
This is a terrible idea. Light cycles affect many natural functions in the world. We already see some of this with light pollution. This idea is basically light pollution on an industrial scale.
Finally, we can replace daylight saving time by just making more daylight instead
How is this under the FCC’s authority?
> The FCC said that the “risks of harm raised on the record regarding Reflect Orbital’s solar reflector are unrelated to the Commission’s role in authorizing use of radiofrequency spectrum.”
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.
The only non-marginal application for this is military, surely.
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.
> The only non-marginal application for this is military, surely.
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 guess it has policing applications, marginally. But most police forces just use helicopters and night vision, and ultimately rely on the disruptive sound of the helicopter to bring people out to look for whoever they are chasing; the noise of a helicopter makes people vigilant.
I just don't really get it.
Illuminating a solar farm for 24 hour power generation?
At the orbits they're talking about, at best 30 minutes before dawn and after sunset. Earth gets in the way, have to go much much higher to get 24 hour coverage, and if you can focus that well over that distance you've got the optics for a super-weapon.
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.
Is it possible it can deliver anywhere near enough solar energy to make this economically viable?
It's not going to be full daylight, is it?
i give you: the industrial revolution and its consequences
Don't we have the moon for that?
Yes but what if you could have a second moon, on-demand?
MAAS
Obvs "MaaS" capitalisation for the full stock valuation.
Obvs(2) a variant of this service has traditionally been provided for free by drunken teens. They might prove to be better and more thoughtful custodians of investment funds.
nothing beats free
We've entered the "bond villain" era of VC startups
Someone tried to recruit me back in 2000 for a startup that would sell a box you connect to your computer allowing you to smell things over the internet. I'll let you guess what industry he was targeting.
Ah yes, the best part of human intimacy: the smells!
Was it ... Musk?
That was some time ago. Musk himself tweeted about getting a volcano lair in 2015.
2014 was the inflection point. 2013 brought us the term unicorn for companies, and was just long enough after the iphone that we were starting to make sense of it. That's when Elon Musk became a household name thanks to Tesla and SpaceX. Then there was Palantir. Google bought Deepmind in 2014. Google Facebook Amazon and Apple showed founders that software startups could transform the world, and the world leapt at the chance.
The fact that they're spelling this Earendil, not Earendel, makes me think this is a direct reference to Tolkien's work. It's pretty weird for dystopian industrial initiatives to be named after characters in a work whose most unambiguous message was that rampant industrialization was ruining the world.
Sounds like a morning star reference (via some obscure Christian texts) which I will draw further towards Lucifer via Latin. Do with this idea as you please.
somebody watched die another day (https://en.wikipedia.org/wiki/Die_Another_Day) and thought, “hmm. great idea.”
It's actually more'n a little bit scary how much of modern "politics" seems as if it could be driven by having watched any of a number of movies and thinking "We should do that!" When I hear people talk about politicians bein' like spoiled brat children in adult bodies, I tend to think that sounds like exactly the type of mentality that could see something all messed up and scary in a movie and want to try to do it in the real world. What makes it even more scary in my mind is that we've allowed those type of people to gather entirely too much money and power such that they have the option available to them to seriously consider trying such horrible ideas.
This is genuinely the stuff of nightmares. Imagine not even being able to have night time any more.
“The regular early morning yell of horror was the sound of Arthur Dent waking up and suddenly remembering where he was" - Douglas Adams
Blog post: https://www.reflectorbital.com/blog-posts/humanity-has-an-en...
Annoyingly and predictably, reads like AI slop. You can practically guess the prompt goes something along the lines of 'write a press release explaining why this bad idea is a good idea'.
Do you have anything to say about the project itself or do you only care about your perception of ai slop?
I swear this is getting so common. “Well I’d be fine with eugenics and sterilization of the poor, but the website uses em-dashes a lot so I think it’s just awful AI slop”.
I think this company intentionally ignored discussing how battery storage has made solar energy a much more effective and viable solution.
Never mind that, they're ignoring light bulbs for the S&R stuff.
At least, best I can make out over this UI choice: https://imgur.com/gallery/bad-ui-5t0O0SH
(Why, of all the things, would someone use a fire as their example for this? Fire is famously a light source. Also, famously, smoke is a thing that blocks out light from above).
And also cheaper than launching stuff into space. This may have been approved but that's a long ways off from actual viability.
Launching a gossamer thin mirror in space is not very expensive. Broad strokes claiming anything launched to space is going to be a more expensive solution has to level with the fact that GPS and quite a lot of telecommunications and Earth observation seem to have incredible leverage if launched to space instead of just using ground based solutions.
For this use, "gossamer thin" is unlikely. You want to control where you point the mirror, it needs a structure that not only doesn't flop around when you torque your spacecraft, but also doesn't have surprise vibrational modes that squeeze and expand the illumination zone.
(Things I'm learning while researching what is now looking like an eight thousand or more word blog post about why a different space thing, data centres, is also not a good investment; my guess is this would be less of a problem if you used mirrors like this to cool the earth by reflecting sunlight away instead of towards).
Ahem. Ladies and Gentlemen. I have placed in orbit a giant mirror that will reflect 40% of the Sun's rays. Thus cooling Earth. Observe.
at some point some rogue country is going to do a starfish-prime event
create an artificial LEO radiation belt on purpose and wipe out 99% of satellites
part of me is oddly rooting for it these days
make Musk a millionaire again
> Eärendil-1
Can everyone just stop with all the LOTR references already why the fuck is this such a thing.
Nah. Should have been named after the Two Trees of Valinor, Telperion and Laurelin.
I initially quite liked it, particularly when the references are a bit more obscure, generally from classic scifi/fantasy. You can end with a nice sounding name and a small wink to fellow nerds.
But it is such a shame that it has started to become the brand of dark-side (militaristic/authoritarian) Silicon Valley: Palantir, Anduril, this… Tolkien would be so very sad.
PS: Palantir is at least rather fitting and honest, it’s literally an evil crystal ball (at least the one shown in the movies).
non-paywall: https://www.nytimes.com/2026/07/10/climate/fcc-space-mirror....
this is the sort of startup we get when memes rule the investing landscape.
Chinese outcry? There’s a lot of that in social media, their bot warriors are everywhere. Same with AI and anything that gives the USA competitive edge.
Apparently there’s a ton here on ycombinator judging by the downvotes
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.
putting mirrors in orbit to have (little) more light is like buiding city underwater to have more cool. ops this last will be way less stupid in the future... To downvote a different opinion without arguing is same kind of attitude: stay fresh.