FCC approves test of space mirror to light night sky
theconversation.com
theconversation.com
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.
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.
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.
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.
Crops means farmland. Farmland means food. Food prevents people from starving to death.
With global warming, existing croplands will become unusable. We'll need new farmland.
That was the whole point of my post, which also discusses other concerns.
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.
(For reference, I think all of these are likely to be somewhere between moderately and incredibly bad ideas...)
The energy has to go somewhere. If you're not reflecting it you're absorbing it and you eventually have to do something else with it.
I suspect just painting all the rooftops and tarmac white will be about as effective as 2000 Starship launches filled with mylar sheets, plus an L1 delivery system because one thing you really don't want for a global warming mitigation is for them to fall out of LEO and burn up almost immediately from the huge drag-to-inertia ratio.
In my book, that would have been a "Fortunately," entry.
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.
> "In general, there's no way to "overlay" light beams on each other, because the whole system has to be reversible".
Behold, my two torches.
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.
There are some non-linear effects that _are_ dependent on the wavelength, but not important to matter here.
Masers are not useful as powerful transmitters, but only as amplifiers with a very low noise or as generators with a very stable frequency.
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?
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?
Are bullets better than knives?
Each thing has its own place.
Like this, for example.
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.
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.
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.
Moreover, the Sun's illuminance is about 1kW/m2 around Earth. 10000×60m2 satellite will thetefore intercept 600MW, so that's 260W/m2 on the focussed area. You're not going to burn anything with that.
Not if you're persistently using it for multi-week sleep deprivation operation to "soften up" an area before attacking.
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.
> in fact there is already no common international agreement about where a nation's boundary extends to in the z-axis. The observed limit is "however high that country can detect and shoot something down"
That's the thing though, if you use that definition then 99.9+% of them are fair game, because _only_ ones around equator at a specific height are at a fixed point. Otherwise they migrate a lot and what country they're over would depend on what second you look.
Artifically capturing that sounds...doomed though.
> Flashes during mirror repointing could disrupt pilots and drivers. The light could also disrupt circadian rhythms of plants, animals and humans
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).
That's a strange reading. What would keep the benefits from cheaper electricity from diffusing to roughly everyone, as they usually do?
I went back to re-read reflectorbital.com, indeed if you're only lighting a solar farm in the middle of nowhere maybe the light pollution is not so bad outside of the targeted zone.
Still fells like a complicated solution to me. Imo we need more storage innovation and investment, a lot more. We know we'll have more and more intermittent renewables electricity production, we just have to store it.
I just don't see why, if this turns out to work, the benefits would not diffuse (principally because I don't see a line of previous innovations where this was not the case, electricity being a prime example of an extremely potent and well diffused commodity).
Now if I take the french grid example that I know best, for the past 7 days the usual spot price is around 100 to 150€/MWh but between 9am to 6 pm it is greatly reduced due to solar production, frequently down to 0 like today (current heatwave, lots of sun). And today between 1 and 3pm we had up to 5GW of solar production being curtailed. That is on top of the nuclear plants already reducing their output by up to 8GW around noon to accommodate solar power. Hydraulic storage was also running but tops at ~3GW.
That is to say there's already unused energy during the day, in theory, if you had a MWh battery you could have charged it for free today (sometimes even been paid to do so) and earned 100€ a few hours later.
One thing I see coming (albeit slowly) is EV cars phasing out IC engines, that once plugged on the grid with their big batteries could be a good distributed storage solution: they recharge during the day whenever the price is low and smooth out the expensive peaks when possible.
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.
It's not going to be full daylight, is 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.
I suppose to make this feasible they would have to up the size of the mirrors. Unless this is somehow dirt cheap I can't imagine farmers or solar operators buying this.
Sure, that's only gonna cost a couple quadrillion dollars or so.
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.
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.
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).
(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).
> Conservation of Etendue,
Sounds like you think I have in mind something like an Archimedes' heat ray. I do not see anything close to that for the presented satellites.
I would aver that the presented design is so far from being useful that making it useful requires solving enough engineering challenges to also enable an Archimedes' heat ray; but again: what is actually shown is not that.
The numbers I see from Reflect Orbital suggest they have an expectation of the apparent brightness fluttering by 5x from internal motion of the reflector. At the scale involved, may be easier to consider the imperfections/ripple as behaving the same as if some of the specular reflection becomes diffuse reflection.
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
(And you actually know that, but since it benefits you, or at least so you are told, you are "not seeing" that.)
Can everyone just stop with all the LOTR references already why the fuck is this such a thing.
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).
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.