101–110 of 116 posts
It’s like announcing you’re going to sell corn starting a year from now when your competition owns all the land corn is grown on, started selling their corn 6 years ago, and has gotten really good at making it cheaper and producing more, based on real world experience.
Interesting there is an optical networking option for end users (claims ~6TBps). Maybe a really dumb question, but how would the end user's ground station maintain connectivity during cloudy weather? Do they have cloud-penetrating lasers from the MEO satellites? Would that interfere with aircraft, astronomy tools, etc? Some short googling says they have lasers that clear a path for a data carrying beam, but that seem…
Some info from NASA optical communication page. "Even Earth’s atmosphere interferes with optical communications. Clouds and mist can interrupt a laser. A solution to this is building multiple ground stations, which are telescopes on Earth that receive infrared waves. If it’s cloudy at one station, the waves can be redirected to a different ground station. With more ground stations, the network can be more flexible du…
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Speed matters a lot. You can fit a lot more walking people than speeding motorcycles in the same space. Satellites need to travel at 8 km/s to not fall down.
> Speed matters a lot Not really. You're correct inasmuch as it increases collision energies. But it also increases momentum, which maintains orbital integrity within predictable bounds. Nobody is maneuvering around satellites, they–and their debris–stay where the math tells them to.
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How many causes Kessler syndrome?
At the altitudes these mega-constellations operate at, kessler syndrome is not a real threat. Even if left unpowered, everything there will naturally re-enter the atmosphere in ~5 years.
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> How many causes Kessler syndrome? Space is huge. Try this trick: the number of satellites in orbit is about the same as the number of planes in the air at any time. (~12,000 [1].) The volume of space from the ground to 50,000 feet is about 200x smaller than the volume from the Karman line to the top of LEO alone (~2,000 km). Put another way, we approach the density of planes in the sky in LEO when there are milliio…
You're ignoring the speed they're travelling at. For a given period of time, a single satellite will travel through a vastly larger volume of space than a single plane.
Nope.
> a single satellite will travel through a vastly larger volume of space than a single plane
Linearly (with a cap). Volume grows faster.
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> This is something people unfamiliar tend to misconceive in their limited thinking on the subject I have a background in astronautical engineering. While you can't tap the brakes to 'slow down', you can impart miniscule amounts of impulse which, over the course of hundreds of orbits, will change your plane by an imperceptible amount from a distance, but tens or hundreds of kilometers up close. OM being OM, you can p…
> you can impart miniscule amounts of impulse which, over the course of hundreds of orbits right. this is what is counter-intuitive for those that are not familiar with space. they don't just light the burner and boost to a new altitude. the part about stopping the acceleration with an opposite burn is often not considered. most think you can fly a space ship like a jet fighter, but in space. can't blame them since t…
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Thought experiment: Let's say you are simulating ten thousand satellites on your computer, and the simulation runs until there is a crash. Now let's say the simulation runs for an hour normally. If you increase the speed of the simulation, you get to a crash in a shorter time. Satellites move about 30x the speed of airliners. Hence, if everything else was similar, one would expect 30x the amount of collisions.
> Satellites move about 30x the speed of airliners. Hence, if everything else was similar, one would expect 30x the amount of collisions Not how orbital mechanics work. Planes maneuvers, get tossed around and have hubs they circle. A plane under my left wing can’t be relied on to continue in a straight line. The satellite can.
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Some info from NASA optical communication page. "Even Earth’s atmosphere interferes with optical communications. Clouds and mist can interrupt a laser. A solution to this is building multiple ground stations, which are telescopes on Earth that receive infrared waves. If it’s cloudy at one station, the waves can be redirected to a different ground station. With more ground stations, the network can be more flexible du…
Multiple ground stations are a fine solution for backhaul, but not most end-user use cases.
All those AI datacenters in space will need a way to get data to them. Bezos can't even build his first constellation and already planning his second... Possibly the real play here is snapping up more frequency licenses on earth (we need them because we're launching any day now promise). They are the real constraining resource and could be used to keep others out of the market for a while.
> They are the real constraining resource and could be used to keep others out of the market for a while I'd love to see a betting market on a unified, global licensing regime lasting for another ten years.
For example, Starlink's "direct to cell" uses terrestrial-assigned 4G/5G frequencies which are already not globally coordinated.
Serving a given market from space already needs a national license anyway, and with today's small and region-dependent spotbeams for both GEO and LEO, I feel like we're going to move to a frequency regime more similar for terrestrial networks than for legacy communications satellites covering a whole hemisphere with one beam.
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What your describing is called Kessler Syndrome https://en.wikipedia.org/wiki/Kessler_syndrome ... It is a very real possibility, but less of a problem below 550km altitude because the decay time is much shorter (and why all of these mega constellations tend to stay at lower altitude, even though ~1000km is generally better for a communications satellite).
> It is a very real possibility It's really not. Not in the popularly-portrayed manner. Militaries have been researching how to intentionally cause such a cascade in even a limited orbit. To my knowledge, there isn't a solution.
If you have 100,000 satellites, and each collision produces 50,000 pieces of shrapnel with some distribution of altitudes and atmospheric drag, it's not that hard to do the math. The cinematic portrayal of cascading failure (ala the movie Gravity) is completely insane, but that doesn't mean this isn't a real problem on a 100 year timescale.