SpaceX is set to launch its first two test satellites on Sunday

Re:SpaceX is set to launch its first two test satellites on ... by gfodor on Saturday February 17, 2018 @02:04PM (#16402116)

I don't know either, but considering the complete lack of existence of the kind of network SpaceX is proposing, or anything close to it, if it's not deployment costs it would have to be some other factor coupled with operating a ~1000 sat network.

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Re:SpaceX is set to launch its first two test satellites on ... by pjc50 on Saturday February 17, 2018 @02:08PM (#16402143)

It's similar to, although much larger than, Iridium. Building it is one thing but making it profitable is another, as it making people accept the latency tradeoffs of satellite.

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Re:SpaceX is set to launch its first two test satellites on ... by randall on Saturday February 17, 2018 @02:22PM (#16402231)

Ars says the latency is 25ms. https://arstechnica.com/information-technology/2018/02/space...

They say it's due to lower orbits. Iridium is fewer satellites so they have to be higher. More w/ lower orbits means lower latency. Do you know if this is too good to be true?

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Re:SpaceX is set to launch its first two test satellites on ... by smoyer on Saturday February 17, 2018 @03:27PM (#16402530)

Most terrestrial systems are now using fiber optics ... the speed of photons in a fiber is about 2/3rds the speed of light. The transmission of radio signals in the vacuum of space is theoretically at the speed of light so:

40000 / pi / 2 = 6366 40000 / 2 * 3 = 60000 60000 / pi / 2 = 9550 9550 - 6366 = 3184

Per the above, any satellite Internet system below about 3000 km above the earth will have latency that's competitive with fiber optics on earth (note that I haven't done the simultaneous solution to account for the uplink/downlink distance so it's actually a bit less). For the SpaceX system, there should be better latency than the terrestrial Internet. Please ignore the rounding ... this is a back-of-the-envelope exercise.

Fiber optics are great and far less susceptible to interference than radio - but if you Google articles on how high-frequency trading companies are installing line-of-sight microwave for their networks you'll see that fiber isn't our fastest technology.

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Re:SpaceX is set to launch its first two test satellites on ... by Game_Ender on Saturday February 17, 2018 @02:15PM (#16402194)

There network will have minimal (30-40ms) latency hit vs ground based systems because there satellites are 300-1000 miles up vs the 20k miles that the current geostationary ones are at.

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