Posted on 11/21/2016 2:45:10 AM PST by LibWhacker
Elon Musk has announced an ambitious plan to put more than 4,000 satellites in space to create a global high-speed internet network.
Musk first turned his attention to internet satellites in 2014, and his plan soon received the backing of Google, which chucked $1bn at Space Exploration Technologies Corp, aka SpaceX. Musk said in January 2015 that the plan would cost at least $10bn. The original number of satellites was pinned at 700, but documents filed with the US Federal Communications Commission show that SpaceX wants to deploy 4,425 satellites, plus “in-orbit spares”, to provide high-speed, global internet coverage. Earth is currently orbited by just 1,400 satellites.
In the filing, SpaceX said: “The system is designed to provide a wide range of broadband and communications services for residential, commercial, institutional, government and professional users worldwide.”
Such a system would provide a space-based alternative to cable, fiber-optics and the other terrestrial internet access currently available. Estimated internet speeds from the satellites could be as high as 23 gigabytes-per-second – and SpaceX says it will periodically improve the satellites over time.
If this initial launch is successful, SpaceX said it will launch the remaining satellites.
“Once fully deployed, the SpaceX system will pass over virtually all parts of the Earth’s surface and therefore, in principle, have the ability to provide ubiquitous global service,” the filing said.
“Because of the combination of orbital planes used in the SpaceX System, including the use of near-polar orbits, every point on the Earth’s surface will see, at all times, a SpaceX satellite at an elevation no less than 40 degrees, with increasing minimum elevation angles at lower latitude.”
Musk’s SpaceX isn’t the only firm looking to satellites as the future of internet connectivity. Google’s Project Loon has a similar plan, albeit involving network-connected balloons, and Richard Branson’s Virgin Galactic previously made an agreement with OneWeb to invest in and deploy satellites in space.
What orifice do those numbers come from?
At 700 miles I get (700/186,000) = 0.00376 seconds, one way. Or, 3.76 ms.
Now for satellite you need 4 one way trips to get a response, (Query up to satellite, down to Earth, response up and response down.) This is 15 ms inherent latency. If the satellite is always above 40 degrees, the max inherent latency is (1/cos 40)=1.3 times this. Still under 20 ms.
That is assuming enough ground stations that you only have to up and then down from the satellite. As a practical matter, this would be one ground station every few hundred miles. Perfectly doable over almost all land masses.
Of course you still have ground based latency, but you have that anyway.
I can tell you right now that my rural DSL had latency in the 150-200 ms range and that was a big issue. I am in the 30-50 range with microwave internet and that seems pretty fast.
The real issue is going to be bandwidth, not latency.
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As far as the naysayers go, the US would own the system. That is an enormous advantage.
Sure people in remote areas don't have phones and internet now, but I bet that in 20 years they would use and, most importantly, pay for phones and internet. Do you want the US or some other country to reap the financial rewards of supplying that?
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