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And even with such a budget: geostationary satellites over the poles are not possible[1] and really hard anywhere but over the equator, really. So that means m
by berkes 5y ago
And even with such a budget: geostationary satellites over the poles are not possible[1] and really hard anywhere but over the equator, really.
So that means most of the south and north part of the earth cannot be covered with such a constellation; they would need to be orbiting satellites, which makes "real time" even harder, because it would require an enormously complex choreography to ensure there's at least one satellite covering each square meter, at all times.
[1] https://physics.stackexchange.com/questions/71582/is-it-possible-to-have-a-geostationary-satellite-over-the-poles https://physics.stackexchange.com/questions/71582/is-it-poss...
- munk-a 5y agoBut, we could always construct a dyson sphere around earth and rely on the rigidity of the structure to provide accurate polar images. That said, it would be really difficult and quite likely not at all worth it.
- recursive 5y ago> But, we could always ... That's a very bold claim with no support provided.
- Robotbeat 5y agoShould be feasible at very high altitudes where gravity is low.
- recursive 5y agoOn the other hand, I think it should not be feasible. How many kilograms of raw materials would be required? And at what altitude? I don't think there's enough propellant on earth to lift that much stuff.
- Sebb767 5y agoPun aside, this is the more in the realm of "theoretically possible" rather than possible right now. And people don't consider sun-sized Dyson spheres impossible, so a planet-sized one should be a piece of cake. Though the live imagery would now need night vision cameras, as we blocked out all our light with our camera support. But one has to take the good with the bad ;)
- munk-a 5y agoHey, you asked me to solve your mouse problem. How was I to know you were allergic to cats! I think most accepted approaches to constructing a sphere involve first building a series of structural components to form a stable net - as such we could stop the process when we've got just enough structure in place for stability and not so much that we need night vision cameras buuuut... I typed that before buying a bunch of night vision stock so please disregard the first portion of this paragraph - we would absolutely need night vision cameras from every angle.
- giantrobot 5y agoMolniya orbits[0] can provide continuous coverage of the poles if you've got a couple in orbit. The orbit has an extremely high altitude apogee and low altitude perigee. The high altitude apogee gives it a long dwell time (from the perspective of the ground). It wouldn't be the most practical orbit for narrow FOV imagery but for polar weather, communications, and monitoring for things like over the pole missile launches they're pretty useful. [0] https://en.m.wikipedia.org/wiki/Molniya_orbit https://en.m.wikipedia.org/wiki/Molniya_orbit
- Robotbeat 5y agoDisagree. The Iridium phone constellation covers the entire planet (which means it has line of sight to the entire planet) and has for about two decades. Starlink will, soon, as well. They’ve already solved the choreography issue you mentioned. The entire globe has about 500 billion square meters. 24 bit uncompressed imagery is thus 1.5TB per global image. With some modest compression, you could get a video stream of that from the Starlink network, although the current design of Starlink would make it hard to have room for an aperture with better than, say, 3 meter resolution.
- riffic 5y agoare your examples geostationary?
- TaylorAlexander 5y agoStarlink is not geostationary. It is a very high density low altitude system.
- Robotbeat 5y agoCorrect. And with a wide field of view (45 degrees), they'd allow a real-time view globally.
- jandrese 5y agoYou aren't taking high res imagery from Geo sats--they are much too far away.