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In reference to the movie Geostorm (2017) a global network of satellites is built and deployed above the Earth for the purpose controlling weather events. Would any largely inhabited planet be the source of raw material for the dominant intelligent species to build such a satellite network around itself? Wouldn't the construction dangerously deplete resources required for the very survival of the species?

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    $\begingroup$ Welcome to the site, KalenGi. Just out of curiosity, have you researched how many satellites are around Earth and where their materials came from? Is there something about these other satellites that makes them different? $\endgroup$ – Frostfyre Feb 27 '18 at 16:29
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    $\begingroup$ Planets are very very big and artificial satellites are very very small. I don't see how, for example, SpaceX's proposed network of thousands and thousands of communications satellites would have the any significant effect on the availability of raw materials. $\endgroup$ – AlexP Feb 27 '18 at 16:56
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    $\begingroup$ @KalenGi - at Science Fiction and Fantasy you asked about the materials for a vast network of satellites. The European Telecommunications Satellite Organization has 51 satellites, Globalstar has 84, The International European Telecommunications Satellite Organization has 85, Iridium has 72, etc. So there are several vast networks of satellites already. Over 6,600 satellites have been launched. Or did you ask about a network of vast satellites? It would make more sense to ask how the satellites were supposed to control the weather. $\endgroup$ – M. A. Golding Feb 27 '18 at 17:49
  • $\begingroup$ What survival resources would be depleted by sending up satelites? $\endgroup$ – corsiKa Feb 27 '18 at 20:49
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There is no way that building satellites can significantly deplete a planet of raw materials.

Just some ballpark figure to clear up your mind:

  • the mass of Earth is 5,972 x 10 24 kg
  • the mass of ISS is 419,455 kg (and ISS is so massive it couldn't be launched in a single piece)

With 1 Earth one could build 10 22 ISS. That number is about 1/10 of the number of atoms in a mole. That number is freaking large.

If we were able to build 1000 ISS a second (and we are way slower than that), it would still take 320 billion years, more than the estimated age of the Universe, to consume the entire planet!

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    $\begingroup$ Downvote because building 1000 ISS a second is so unrealistic. It would take several minutes for sure. $\endgroup$ – Willk Feb 27 '18 at 17:33
  • $\begingroup$ Math checks out on my calculator at least... $\endgroup$ – Muuski Feb 27 '18 at 19:27
  • $\begingroup$ Although I agree with your conclusion, the mass of the Earth isn't all usable (or necessary) for building spacecraft. You're ultimately limited by whatever you run out of first. $\endgroup$ – Rob Rose Feb 27 '18 at 19:57
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    $\begingroup$ @Willk, do you read the I in ISS as International or as Ikea? ;) $\endgroup$ – L.Dutch - Reinstate Monica Feb 27 '18 at 20:05
  • $\begingroup$ I overestimated the total mass of the satellites required to cover the globe in LEO relative to the mass of the Earth. JBH's and Arsenal's answers point out that the bigger problem is the energy requirement for both extraction of the minerals and launching the satellites into orbit. $\endgroup$ – KalenGi Feb 28 '18 at 18:39
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To build in L.Dutch's answer (which I upvoted, and so should everyone else), this chart tells you the estimated amount of periodic table elements in the earth's crust (just the crust).

The biggest problem is that the rarest materials in the crust are, by definition, not required for the survivial of any species. But, let's pretend that they are.

Let's also assume that the abundance of the materials holds true throughout the planetary volume.

  • Protactinium 9.9x10-13% of the earth's crust (aka, the earth).

  • Earth's mass is 5.972x1024

  • Available Protactinium: 5.912x1012kg.

Worst case: Your satelites need 100% protactinium (don't worry about why, we're just making a point). Once again borrowing L.Dutch's numbers for the ISS, we can build 14.1 million ISS, even if we're depending solely on one of the least available materials on the planet.

The limiting issue is actually cost — as in how much it costs to extract the (e.g.) protactinium from the ground. That cost could (and probably would) break national economies.

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Let's just consider an extreme example - a solid shell around earth in a geostationary orbit of 1 cm thickness.

That shell would have a volume of around 162E12 m³ (4*pi*(36000km)^2*1cm).

If you made that shell out of iron, you would need 1.3E18 kg of iron to build it.

Now let's say because you limit yourself to mining the Earth continental crust for getting all this iron. The continental crust weighs an estimate of 2.2E22 kg and contains about 5% iron. So the continental crust contains around 1.1E21 kg of iron.

So basically you would need to mine around 0.1% of the iron of Earths continental crust to build a 1 cm massive iron shell around Earth.

Of course at the current rate that would take around a million years (1e12 kg/yr) to do and getting it into orbit would be another problem. Maybe the biggest problem of it. But I don't know enough about orbital mechanics to work out how much fuel you need to do that.

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  • $\begingroup$ I'm trying to imagine what kind of orbital velocity a solid shell of matter would need to minimize stress on such a structure. Does anyone have a link? $\endgroup$ – Muuski Feb 27 '18 at 19:32
  • $\begingroup$ Orbital velocity of a satellite in geostationary earth orbit is about 3 km/s. $\endgroup$ – prl Feb 28 '18 at 7:35
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Wouldn't the construction dangerously deplete resources required for the very survival of the species?

No, it should be fine in terms of survival of the species in terms of raw materials. But they may deplete rare resources depending on what goes into the satellite, gold and other stuff. Also if a single country was doing this it might deplete some of their resources.

However large scale work like this could cause political and social turmoil and perhaps economic collapse either during or after (a lot of unemployed people after and huge amounts of money spent during) which may lead to the species exterminating itself or something along those lines.

The ability to control the weather could easily be seen as a defense threat to many countries. E.g., if North Korea started this project there would be quite a bit of complaining.

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If we were actually building enough satellites to consume a significant portion of our iron reserves, the greater problem would be launching them. It is expensive to launch things into orbit. On the Earth, we can't use a space catapult, because there's that atmosphere in the way. So we'd either invent a material cable of forming a space elevator tether or we'd have to use rockets. Chances are that we'd run out of rocket fuel before we ran out of iron.

Another problem is that rockets waste a tremendous amount of energy. Atmospheric friction, burning rocket fuel, those things create a great deal of heat. You think global warming is bad now, wait until you try launching 5% of the Earth's crust into space. And that's without counting the carbon dioxide left in the atmosphere by the rocket fuel after it burns. The only reason it's not a problem now is that our space operations are on such a tiny scale.

It would actually be cheaper, at that level of scale, to mine minerals in the asteroid belt and shoot the satellites into orbit. Then we could use solar panels to power a space catapult. The mining ships could use solar sails to get to the catapult.

If we ran out of asteroids, we could get iron from Mars. Smaller planet means less of a gravity well. And the sparse atmosphere makes friction less of an issue. A space catapult would be practical there, or on the Earth's Moon.

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  • $\begingroup$ If are moving significant fractions of the crust by rocket direct heating probably starts to matter, also at that point it may be more efficient to shove the whole atmosphere into storage so we could use a catapult. $\endgroup$ – user25818 Feb 27 '18 at 21:32
  • $\begingroup$ Interestingly, aluminum, rather than iron, is more preferred for satellites. That actually emphasizes your point, since aluminum is 8% of the crust, while iron is 5%. $\endgroup$ – fyrepenguin Feb 28 '18 at 2:53

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