Hacker News Reader

Comment by andwur | Hacker News Reader

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?

View on HN

Think of the military benefits.

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.

I wasn’t speculating on people’s motives; I was speculating on whether the idea is feasible. I don’t think that it is.

Assuming the orbit is at 200km, these mirrors could only focus the image of the Sun on a 1.7km wide disk (that's (Sun diameter)/(Sun's distance)×(Earth distance)).

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.

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.

> Daylight helps you just as much as your enemy.

Not if you're persistently using it for multi-week sleep deprivation operation to "soften up" an area before attacking.

I guess there's some niche applications but that's easily defeated with blackout curtains. Plus soldiers on a base are already pulling night shifts, making everyone on a "night shift". Still, they can only guarantee 100 lux (comparable to indoor lighting) for continuous periods with 50k+ satellites. That's a shit ton of infrastructure all tuned into one small operation.

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).

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"

Frankly I don't see this happening before the year of the Depend Adult Undergarment

I've read enough of it to get the reference.

Same. By that point, I realized if that was one thing I got, I must have missed even more.

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?

Is it ever, ever going to be cheaper or easier or more effective than just launching a missile? Seems...unlikely just on the face of it.

Are missiles better than bullets?

Are bullets better than knives?

Each thing has its own place.

Not every possible thing has real situations where it's better. There are legitimately terrible solutions to problems, that are dominated by better ones in every situation.

Like this, for example.

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.

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.

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.

But they'd be competing with the old fashioned stadium lights. I don't think they would be cheaper somehow.

Its obviously just a way to separate investors from their cash.

Reply on news.ycombinator.com