Russian crowdfunded reflector satellite aims to be “brightest star in the sky” | Hacker News Reader

Russian crowdfunded reflector satellite aims to be “brightest star in the sky”

arstechnica.com

81 pointschris-at81 comments

In the 1980s there was a proposal for something similar, a "light ring in space" from Europe. That project was decorative, a pretty object to look at.

It was obviously a stupid idea and scientists did a good job of explaining why.

https://books.google.co.uk/books?id=i6PR8dMk1GUC&pg=PA60&lpg...

(For fuck's sake Google. Look at that stupid hideous URL.)

"a sky filled with orbiting trademarks or political symbols. These billboards, perpetually overhead, from which there would be no escape on earth."

Just increase light pollution enough and the problem is solved :)

Lol, AdBlock Lux

Michael Herf should build a version of flux that actually changes the color of the night sky, at night.

Once enough people bought shitty hackable color-changing light bulbs...

Orbital mechanics doesn't make that feasible, though. You'd only be able to have something transiently appear in the sky, because satellites can't orbit around in lockstep like that. And it would be freakishly expensive even for that.

Isn't that what geostationary orbit is? Unless I'm missing something here...

Technically yes, but geostationary is over 22 thousand miles out (nearly a hundred times as far away as the ISS). You'd need a big-ass billboard.

Ah, didn't consider that!

Unless your logo is a straight line of dots (like Lastpass's recent logo change, I guess), you'd still have everything not on that line sine-wave wobbling once per day. You'd get one window of your logo looking good for maybe an hour or two, and 12 hours later, it would be upside down. Presumably you'd time it so your target audience sees the logo in the evening, but there are still some people likely to see it upside down in the sky. Marketing departments get fussy about things like that.

Plus in that orbit you're much farther away, and need to be much brighter than the satellite proposed. You won't get "brightest star in the sky" with 12 sq meters of reflection from geosync. I'm pretty sure you'd get "effectively invisible".

It would have a diameter of 0.5 degrees--the apparent diameter of the Moon. It would last in orbit for about three years, before the drag of the Earth's atmosphere and the pressure of solar radiation on the spheres caused it to spiral inwards and eventually burn up in the lower atmosphere.

The Light Ring would by visible for 10 minutes out of every 90 minutes for two orbits after the Sun sets and two before the sun rises.

So, I understand why it's a bad idea, and how it affects astronomy, and why we're better off not having done it. I just want to say that would have been awesome to see, and I totally understand why they wanted to do it. Now I'm a little sad we didn't get to see something like that.

I guess the next step would be to crowdfund a rocket to remove this light pollution/ad?

Who'd risk Kessler Effect?

https://en.wikipedia.org/wiki/Kessler_syndrome

You don't have to necessarily explode it, just de-orbit it. If you're going to hit it ballistically, then you've already got the capability to de-orbit without risk of cascade.

This is beyond the scope of my knowledge so maybe it's a stupid question, but why doesn't space debris deorbit on its own like anything else not in geostationary orbit?

From the wikipedia entry:

> Orbital decay is much slower at altitudes where atmospheric drag is insignificant. Slight atmospheric drag, lunar perturbation, and solar wind drag can gradually bring debris down to lower altitudes where fragments finally reenter, but this process can take millennia at very high altitudes.

The US's latest anti-satellite test struck from higher altitude than the target, aiming the debris field toward the atmosphere where it quickly de-orbited.

I hadn't heard that part of the story before. I found a source. [0] Sounds like the strategy wasn't super successful. Impressive ballistics though!

[0]: http://swfound.org/media/167224/through_a_glass_darkly_march...

It will be large (after deploying the reflecting facets) and lightweight and in a low orbit. It will remove itself just fine faster than you manage to crowdfund a rocket.

The idea expressed at the end of the article "orbiting mirrors could be used to extend the length of daylight hours for harvests" actually sounds like it could be very reasonable. Vertical farming and aquaponics is currently restricted by light to a large extent. If this solves the lighting problem for vertical farming, we could end up with a 10000 layer farm built into an old mine quary that could feed a large country. And then all of that farm land could be left to nature :) Deforestation could be reversed, and the reversal of deforestation could play a key roll in reducing the roll of carbon emissions...

A satellite doesn't help you with vertical farming at all, as the light is still coming down from above.

You can move light. Light flies really fast [citation needed] and is easilly and efficiently reflected.

How are you going to reflect it into 10000 layers? Your mirror surface area needs to be as big as the area of light you want to capture, and it all needs to be in clear view of the satellite.

You may as well just remove the mirrors and put the farms where the mirrors are.

If you do farming in space, you have many problems. You have to get the food down, and water up, you have to bring up all sorts of materials and store them in space... It is much easier to get light down than to get seeds and water and nutrients up, and then food back down again.

If you get light into a clear material which has a reflective surface( almost any clear material does ;) ) then the light will reflect internally and flow down the material, while seeping out the sides. That is how fiber optics works, but it doesn't have to be fiber, almost any clear material would do...

I think you're vastly overestimating how much area would be available in a farm built into an old quarry.

A 4km by 1km parcel of land is not large for farming. But put vertically, it represents the biggest open cut mines ever made.

So, working with 4Km2... There are 13 million square kilometers of arible land on earth: https://en.wikipedia.org/wiki/Agricultural_land . If the virtical farm is strung up with 400 meters of 10cm layers, that makes 4000 layers. That would be 16 000 square kilometers of farming area, or a bit over 0.1% of all arible land. I think that with modern vertical farming, using a 24 hour year around light source, the farming surface can produce several times the avarage arible land production. Lets say 4 times... That would make almost 0.5% of the world farm production in just one tiny area. So it would take just 200 such constructions to replace tradtional farming entirely...

You need arable soil for all 4000 layers. You will be taking valuable topsoil from just as much land.

That is not how aquaponics and vertical farming work. They use solulable nutrients which are either gained through a nutrient cycle (the water flows down to a pool which has fish in it), or via mining of otherwise hard to get nutrients. Soil is not used. While the source of all these nutrients is a problem, it is comparible to the huge quantities of petrolium based fertilizers that we use today. It is bad, but what we have now is bad too...

... so you are proposing a bad idea that seems pretty wrong from multiple aspects. generally hydroponics is a sht cheap substitute for real growing for those who cannot afford quality vegetables (sadly, I sometimes fall down that hole too and then regret this decision while eating this tasteless cr*p full of unhealthy chemistry).

no, thank you for many reasons

If you have 4000 layers, you need 4000 times as much light, so you need a 16000km^2 orbital mirror focusing on your farm's elaborate set of light-pipes. The highly focused light, like a CSP plant, would ignite birds that flew into the beam. At that scale it would probably alter the local climate, given the amount of heat transferred to the air.

Few questions:

- How does a mirror make the foliage transparent?

- How does transparent foliage absorb energy for photosynthesis?

- How do you boost the energy from the light 16000 times (4000 layers * "lets say 4 times") without destroying the plants (and probably a lot more)?

- What are these <10cm crops we can replace the current unwieldy crops with?

A lot of plants measure seasonal change by the length of the day. This might work for some crops but your broccoli would probably bolt or never grow flowers in that environment.

I hope this idea literally never gets off the ground. If one person/company gets approval to go ahead, there will be no end to the people/companies seeking approval, and there goes ground-based astronomy.

Yeah we don't need Russian "taste" in space. As someone who's traveled there, they have very different ideas on whats socially acceptable. Big ads/lights in the sky might be fine there, but certainly not everywhere. This is the kind of thing we should all be fighting against, not encouraging with "me too" upvotes on social media. This is simply space graffiti. The commercialization of space should not mean the ad-ification of space.

As launch prices drop, I think we'll see more of these shenanigans. This really should be stopped now.

>This really should be stopped now.

Sure, stopping this instance is possibly worth the trouble, but what about next time? Amateur satellites are already possible, thus the possibility of an ever increasing occurrence of space graffiti.

The first issue is how one can stop space graffiti entirely. Should the UN get involved? Should NATO get involved? In any case, it would either be a statutory matter (pass a law against however-defined graffiti in space) or a military matter (use generally expensive anti-satellite missiles or lasers). The means to stop space graffiti seems to be rather expensive and politically charged/dependent. (for reference, I am not assuming that you want to do anything in particular, but I bring up criminalization of and shooting down space graffiti just to get on with my point.)

The second issue is what harm is cause by space graffiti. Sure, unaware astronomers would be at least annoyed. Do they deserve a natural night sky to make their jobs easier? Space graffiti seems like art to me, but space debris seems the more serious possible problem. Since this specific instance of space graffiti seems to have planned for that, I think that harm is not a problem herewith.

The third issue is whether anyone is obliged to not put astronomically obnoxious objects in orbit around earth; is this the same kind of "don't do" as assault or vandalism? If this specific instance of space graffiti were launched without public awareness, then astronomers might find this space art to be a problem, but I think that astronomers are probably watching news outlets for these sort of launches. Anything on the other side of the space graffiti is not un-see-able, but is that reason enough to either criminalize or shoot down space graffiti. Does anyone deserve the night sky to contain only natural light sources, but also a few super-useful objects (e.g. GPS satellites)?

I bring all this up, because I hope to demonstrate that space graffiti, as stupid as it may be, is a very limited problem. It seems that the stupidity associated with a problem makes the problem seem bigger; ask anyone who has seen prank videos on YouTube whether the government should try to stop pranks. Graffiti on earth is often vandalism and art, yet nobody owns space so space graffiti cannot be vandalism but is still some sort of art.

(Edit: my comment on space debris was completely redundant with something you said elsewhere in your post!)

Would it be feasible to deploy massive solar sails to cast a shadow and prevent solar heat from hitting the earth, so that over enough time it might reverse some of the effects of global warming?

It's not feasible because of cost and political will.

It might not be as expensive as it sounds. First of all a shadow can be cast using very very light-weight material, maybe even get the mass from objects already in space. Another benefit is that it can be controlled much more carefully than other proposals that have been proposed by serious publications that involve dispersing stuff into the atmosphere itself.

> First of all a shadow can be cast using very very light-weight material

Not in space. Unless the material is an absolutely perfect reflector across the entire EM spectrum, which simply isn't possible, any structure would melt pretty much instantly. You'd have to make radiators that are as big or bigger than the shade structure in order to radiate that heat away and you'd have to make the entire structure much bigger than the shade part because otherwise you'd just be radiating the absorbed heat back at the Earth.

> perfect reflector across the entire EM spectrum, which simply isn't possible

You don't need it to be a perfect reflector across the entire spectrum, 200 to 2000 nm is enough.

And according to "Solar Absorptance and Thermal Emittance of Some Common Spacecraft Thermal-Control Coatings", e.g. Kapton film reflects 92% of the entire solar spectrum.

Sorry I meant be completely transparent or reflective. If even < 1% is absorbed in any way, the heat will steadily build up and eventually start to melt the material, which changes its properties usually causing it to absorb more and more heat (causing a runaway heating effect). You can either radiate that heat back towards the sun (not going to work) or towards the earth which defeats the purpose. This is one of the most basic design constraints in any spacecraft simply because there is no way to convect heat away like we do within our atmosphere.

Since black body radiators are very inefficient, you'd have to build a massive umbrella with an oversized "heatsink" that dumps way more heat to the sides than it does towards the earth or absorbs energy from the sun. I don't even want to imagine how massive of an engineering challenge that would be.

Why can't it radiate heat towards the earth? If you reflect 85% and radiate the remaining 15% towards earth, that's a net win, right?

Again, that would require perfect reflection for that 85% of spectrum and perfect transparency and/or a perfect radiator for the other 15%. If that kind of material is possible, we're capable of producing it, and the x% is capable of feeding all of the photosynthetic organisms on Earth it would be totally fine.

However, there is zero evidence that such a perfect material can even exist let alone be produced and maintained at a scale capable of shielding the earth. Any imperfections will absorb heat and steadily destroy the shielding material in runaway overheating.

>Again, that would require perfect reflection for that 85% of spectrum and perfect transparency and/or a perfect radiator for the other 15%.

What? No! You use a semi-good reflector that reflects 85%. You use any marginally-okay radiator and it will get rid of the other 15% No need for perfect materials at all.

>and the x% is capable of feeding all of the photosynthetic organisms on Earth it would be totally fine.

What? The point is to blot out 2% of the sun. You don't need the remnant light from that area of the sky to feed anything. Plants will just have to get by on having 98% as much light.

>Any imperfections will absorb heat and steadily destroy the shielding material in runaway overheating.

What? Any imperfections will make that part heat up slightly more, which makes that part radiate more, and then it reaches equilibrium. It's a sheet of plastic/metal. It's not going to be within a hair-thin safety margin of self-destruction.

Look into the research and tests on solar sails. It's not a difficult problem. Most of the light is reflected, and the rest is not enough to overheat it. Casting a shadow does not require 100% of photons be blocked.

Solar sails are designed to move away from a large source of photons which decreases their energy input exponentially as they move. They are also attached to a spacecraft with its own heat dumping mechanism which means most of the energy can conduct away from the sails into the rest of the more massive thermal system.

The thermal mass of the rest doesn't matter, only how much it can radiate over the long term. And an enormous film makes a good radiator.

Any solar sail capable of starting around Earth is capable of hanging around Earth indefinitely without heat problems.

Certain designs can't go very close to the sun, some can. Many designs would work just fine for a solar shade.

》 The thermal mass of the rest doesn't matter, only how much it can radiate over the long term. And an enormous film makes a good radiator.

Unless you've got a perfect material that can be accelerated by radiation pressure and radiate all heat away, then the rest of the spacecraft mass very much matters because that's where 99+% of the heat will migrate to. Whether a "film" is a good raditor or not (AND a good solar sail) depends entirely on the type of material so I don't know where you're getting your assumptions from.

》 Certain designs can't go very close to the sun, some can. Many designs would work just fine for a solar shade.

Do you have a link to such a design? I would be greatly interested in learning about it as I have not heard of a single practical design that can do what you're claiming.

If you need to deal with heat, you set up one side to be good at reflecting, and the other side to be good at radiating. That doesn't require perfect materials. It doesn't even require particularly great materials. For the job of shading the earth, you would do fine with a design that only reflected half the light. We can do much better than that with existing technology.

https://en.wikipedia.org/wiki/Solar_sail#Materials talks a bit about which designs can handle getting significantly closer to the sun than Earth. None of the designs there would have trouble with heat if they were in orbit around Earth.

This sounds like the back-story of some sort of post-apocalyptic sci-fi movie.

It's an idea that's been floated in scifi. The scale of it is huge, though, and you'd have to consider the CO2 emissions of the necessary launch and manufacturing. Probably only feasible if you could make it on the moon.

Please, remember that we literally live on solar energy. That's what we eat. And that's also the most promising alternative from the global warming causing fossil fuels.

So, please, don't take the solar energy away.

Engineering aside, you could perhaps position this shadow strategically over some place that is uninhabited and which wouldn't cause too much weirdness in our climate. Or perhaps many small shadows. My guess would be that you would want them over the oceans. Or maybe Kim Jong-un's house.

Alternatively, if geostationary is too high up, perhaps just wrap them at a particular latitude near the equator, spaced out so they just make an effect like a perpetually cloudy day. You then just have to keep your solar panels and needy crops off that latitude.

If you want a big enough effect to detail global warming, you'll need a big enough effect to change the climate. There's no place it "wouldn't cause too much weirdness in our climate".

If you place them over the equator, you've just destroyed the places with the highest plant growing and solar energy harvesting potential. Granted it is not the most used place of the world today, just the one with most potential.

If you place the shadows over the oceans, you'll completely change the environment there, and help destroy its bigger species, that we eat too.

Well, the whole point is that the Earth, due to greenhouse effects, is taking in too much sunlight compared to what it is radiating back out into space. So yeah, you're going to be reducing the total potential harvestable sunlight getting to Earth. However, that's not really a constraint for us at the moment. We just care about tapping sunlight in places near where there is a demand for energy. So, you could probably find a nice band around the Earth where the inability to place highly efficient solar panels wouldn't be missed sorely.

By 'too much weirdness' I'm referring to instigating entirely new and dangerous weather patterns. Ideally, you could keep the weather roughly the same, with the lowered temperatures disbursed enough to create a measurable but not easily noticeable effect.

And we're also not talking about plunging the area into permanent darkness, we're talking about enough reflection to reduce average global temperatures by a few degrees (or at least prevent them from rising further). I expect that could be done, if spread out enough, without enough of an impact on any one area to impact local environments.

Of course, this is all just theoretical. I doubt it's actually a reasonable course of action. I just don't think this is why it isn't.

The suggested amount of sunlight to block for cooling the earth is 1-2%. You're being ridiculous.

Without going into too many details, something like this is used in the book Sunstorm by Arthur C. Clarke and Stephen Baxter.

https://en.wikipedia.org/wiki/Sunstorm_(novel)

I think the short answer is 1. it's much cheaper to simply reduce CO2 emission, and 2. "An Earth with more CO2 and less incident sunlight" is not the same as "An Earth with less CO2 and the same sunlight as before" (e.g., think of ocean acidification).

This reminds me of a sci-fi book that I cannot remember the name of, in which the Coca Cola company deliberately initiates the supernovae of 100+ stars in order to spell out the message "COKE ADDS LIFE!" in the night sky.

> In the Red Dwarf (1988-current) spinoff novel Red Dwarf: Infinity Welcomes Careful Drivers (1989) by Grant Naylor, stars are deliberately detonated to create a pattern of supernovae spelling out a Coke ad in Earth's sky.

This page has a bunch of similar examples: http://www.sf-encyclopedia.com/entry/advertising

According to https://en.wikipedia.org/wiki/Space_advertising it was "a Red Dwarf novel". The page doesn't say which one, but a bit of googling suggests it may have been Infinity Welcomes Careful Drivers.

How embarrassing for me :)

For some reason I was half convinced it was HGTTG. Probably because I read them at about the same time, when I was about 10.

Heinlein's _The Man Who Sold The Moon_ has the main character extort money from basically everyone by telling them that their rivals were planning on drawing a logo on the moon. He either names Coca-Cola explicitly, or else uses an expy of them...

I stumbled upon this article the other day: http://motherboard.vice.com/read/the-man-who-turned-night-in... it's about the previous Znamya experiments https://en.wikipedia.org/wiki/Znamya_%28satellite%29

Has anyone thought of the impact this might have on earth based observations? We already have Iridium flares that happen from shiny satellite parts, and these flares have disturbed observations from various observatories (and this wasn't even intentional).

https://en.wikipedia.org/wiki/Satellite_flare

Technically, isn't the sun the "brightest star in the sky"?

Not at night!

The "Russian moon" has been an on again off again urban legend/hoax for probably 50 years. Don't fall for it again.

We need a kickstarter to bring this thing down if it's ever launched.

With a solar cell and a tether, it could stay up forever?

But, why?

This is a smaller version of this:

" Znamya was an experiment in orbital lighting—using orbiting mirrors to light parts of the earth (or even entire cities) at night with reflected sunlight.

The idea behind the program was that a collection of orbiting mirrors could be used to extend the length of daylight hours for harvests, major construction projects, and disaster response operations, a concept originally concocted by German space theorist Hermann Oberth (one of the fathers of modern rocketry) in the 1920s "

I guess because the Earth is still not warm enough ...

We should be doing the opposite. Engineering and deploying ultra-light weight material that unfolds into massive solar sails that can be controlled carefully to cast a shadow and cool the earth slowly over the course of decades to counteract some of the effects of global warming.

From the Russian site, googletranslated:

" This space satellite, which will be the brightest star in the night sky. Star, which will remind the world who was the first in space and show that the contribution to space exploration can contribute not only to the state and corporations. "

So it is visual pollution.

I just puked.

Good thing this is a russian kickstarter thing - with 95% probability it is a fraud.

so the first piece of ringworld?

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