dual_sport_dork@lemmy.world 3 days ago
In addition to being a moronic idea, this is also physically infeasible as I outlined in excruciating detail in my comment the last time this came up. The takeaway is that this is an investor scam for sure, and the side effects outlined in this article are just a fun (!) and exciting (!) sideshow if these bozos actually do mange to get a single mirror off the ground and deployed. Which they probably won’t.
I’d like to see that comment if you could link it!
I mean just on the surface of it, this is completely preposterous.
The first thing that comes to mind is you can only cover so much area. 4000 satellites would cover the dog park near me. In the scope of an undertaking like this, it’s a trivial amount of energy they could possibly gather?
That’s the main hurdle.
Re-finding this was a pain in the ass because I didn’t save it. lemmy.world/post/19485246/12219336
If I had to build such a system, instead of a few satellites with really big mirrors I’d instead have a massive number of small satellites with smaller mirrors. Obviously then any area I’d want to light up, I’d have to hit with a number of the satellites - probably dozens at least or even hundreds of them for decent sized area. That would at least alleviate a few of the problems - aiming would be easier. As satellites move out of range new satellites would be moving in range. Long shadows from the angle of satellite near the edge of their range wouldn’t be as much of a problem as I’d be hitting any spot from a variety of angles. That the satellites would be useless for about 75% of their orbit I could make up for by launching even more satellites.
Of course, it would still be hugely impractical and there would still be major limitations. I’m still not sure how you could manage the aiming - the satellites would have to be continuously adjusting their aim to track their target. Reaction wheels can only do so much and using thrusters you’d burn through propellant like crazy. Launching the required array of satellites would be outrageously expensive and you’d need thousands of them. Eventually something would go wrong - you’d have a collision or one would break up and you’d Kessler yourself right out of business.
Thanks for the write up!
I’m curious how strong an effect atmospheric scattering would have, even after all that!
The same a what the sun already has to deal with, really. If your reflection and focus were somehow 100% perfect (impossible, but maybe you could get close) then attenuation from the atmosphere would be the same as what happens to ordinary sunlight over the same surface area, since that also has to pass through the same amount of atmosphere.
Your point about poinitng (ha!) is incorrect, its pretty trivial to maintain pointing at the target. Hubble achived 7mas pointing accuracy over extended periods (thats ~0.000002degrees) with technology more than 30 years out of date. That gives you ~1.2m accuracy from geostationary orbit, which seems fine.
The real point is getting a mirror which is large enough and perfect enough into orbit is completely infeasible. As you rightly say, the maximum potential power it can provide is equal to solar insolation time its area.
The aiming is still a problem. The Hubble is relatively small. Even then, it can’t track fast enough to image the moon, let alone the earth’s surface.
Any useful reflector would be measured in Km^2 . Aiming that, with the same precision as Hubble would be a tall order. Added to that, the mirror would have to be light enough to launch. You’re basically trying to aim a sheet of tinfoil, as large as a stadium (minimum), with active tracking.
What about Lagrange points? If the JWST can focus on a target millions of LY away, surely a few giant mirrors could focus on a reasonably small section of earth.
Even if they could, the L1 point would be directly centered between the Sun and Earth on the already illuminated side of the planet, which is obviously not helpful. The L2 point would be on the other side of the Earth, on its dark side, and completely within its shadow so also not helpful.
From the L4/L5 points you would not only be rather far away but also only able to hit areas pretty close to the dusk line anyhow.
Yeah this is another rugpull meant to allow the rich to get richer on the money of idiots
JoshuaFalken@lemmy.world 2 days ago
I disagree they are bozos. I’m actually coming around on the idea. Not the mirror thing of course, but the VC grift using a flashy idea. Millions of dollars and the only thing you make is a slideshow? Brilliant.
SaraTonin@lemmy.world 2 days ago
It’s tricky business. The idea has to be plausible enough to attract investors, but implausible enough not to get looked at too closely by clever investors. Similarly, you have to drum up enough publicity to get interest, but not enough to get scrutiny.
Get the balance wrong and you get Theranos.
anomnom@sh.itjust.works 2 days ago
Theranos made a bunch of money for its creators, they just messed up by thinking they could keep lying, when they could have just admitted failure at some point and then moved on to the next grift.
Since then crypto schemes came atone and made it way easier to swindle dumb investors. So the VC grift isn’t as attractive.
ashenone@lemmy.ml 2 days ago
I’m gonna start a startup called startup starter and my business plan will be selling business plans to startups that are flashy enough to attract VC money so you can siphon off as much as possible before the business folds.
njordomir@lemmy.world 2 days ago
So you offer Startup Starter™ franchises so I can help startup starters in my area find startup starting ideas?
Archer@lemmy.world 2 days ago
Sure, just attend their crypto event