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SpaceX plans worldwide satellite Internet with low latency, gigabit speed

arstechnica.com

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Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed

#421

Post by Symmetry »

gibybo wrote: post #86
andrepd wrote: post #52

Earlier quoted context omitted.

Still. What's the cost of deploying 800 sattelites vs cost of fiber infrastructure for 6 million people?

I think it might be comparable. It's really hard to estimate since we don't know their satellite costs, but $100 million per satellite (launched) is probably a good starting point. That ends up being $13k capital cost per customer. If they can borrow capital at 5% or less, that works out to ~$55/month. But if they succeed with reusable rockets (and it sure looks like they will), they can probably drop the launch cost…

They're only going for 51 orbital planes and it's fairly simple to spread out many satellites from a single launch if they're in the same orbital plane. And a Falcon 9 can carry 20,000 kg to orbit whereas each satellite is pretty light. Some people on /r/spacex calculated that the binding constraint is actually the volume of the Falcon 9 payload fairing and they'll be able to launch 20-25 satellites at a go. And I would expect that mass produced satellites to be far cheaper on the margin than bespoke ones. All of which is to say that it's probably more like $10 million per satellite launched.

Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed

#422

Post by Symmetry »

mnw21cam wrote: post #366
oillio wrote: post #288

Earlier quoted context omitted.

Why not? I wonder if you could construct a polar orbit that followed the daylight around the earth. Add higher concentrations of satellites to the orbits that correspond to the higher traffic hours of the day.

Yes, it's called a sun-synchronous orbit https://en.wikipedia.org/wiki/Sun-synchronous_orbit The exact orbit has to be arranged so that it precesses once a year, keeping it aligned with a particular local time of day. "Typical sun-synchronous orbits are about 600–800 km in altitude, with periods in the 96–100 minute range, and inclinations of around 98°"

There are 5 planes of 75 satellites planned by SpaceX later on for 81 degrees inclination which might be sun syncronous during the day but the initial 32 planes of 50 satellites are all headed for 53 degrees inclination which I'm sure isn't. You can't have sun synchronous orbits anyways for those satellites providing coverage during the night.

Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed

#423

Post by sbalea »

Rebelgecko wrote: post #242
lettergram wrote: post #39

Earlier quoted context omitted.

I'm curious if they can launch multiple at once. I assume they can, and on top of that, once they can reuse rockets My guess is the cost might be as little as a million ( or less ) for a satellite in orbit. That would be, what, $9 billion? That sounds like a lot, until you realize they can spread that cost over 2-3 years and have millions (if not billions) of people paying for internet. This would replace cellphone p…

I'm not an RF person, but I don't think this will be practical for cell phones in the near future. Smart phone batteries barely make it through the day as is, and inverse square laws aren't on our side when it comes to space (even low earth orbit). My phone would last about an hour if it was transmitting at 10 watts

Also, I'm pretty sure you will not want a 10 watts microwave emitter couple of inches from your brain

Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed

#424

Post by mehdix »

schiffern wrote: post #357
katzgrau wrote: post #7

Free, global internet access is the next step toward a smarter, more progressive planet. I don't even care about the speed - if the only thing users could access was wikipedia, I'd still personally donate to the project. I cannot emphasize how important democratizing knowledge is to me (and many others).

>Free, Not free according to Musk. https://www.youtube.com/watch?v=AHeZHyOnsm4&t=12m37s > Well it can't be free. Because then we'll, like, we'll go out of business. [laugh] > No, no, it can't be free to the user. I don't think so. > This would be... this would cost a lot to build. Ultimately over time to build the full version of the system, we're talking about something that would be 10 or 15 billion dollars to crea…

I guess the OP means "free" as in "freedom" not as in "free beer".

Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed

#425

Post by Symmetry »

PaulHoule wrote: post #414

Will this cause the Kessler syndrome?

No. First off, these satellites are all in the relatively underpopulated upper section of low Earth orbit hugging the lower reaches of the inner Van Allen belt at ~1,000km above the surface. Most satellites in LEO are closer to 300 km up. So there aren't really any non-ElonNet satellites to worry about except for ones in highly eccentric polar orbits and those are few enough to be avoidable. They also have fairly aggressive plans to de-orbit them at the end of their lives which makes me happy.

The big danger for Kessler syndrome right now is all the satellites whizzing around Earth in polar orbits that all cross over the Earth's poles.

Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed

#426

Post by Symmetry »

lettergram wrote: post #39
blurbleblurble wrote: post #13

Earlier quoted context omitted.

seems so expensive for such a short lifespan

I'm curious if they can launch multiple at once. I assume they can, and on top of that, once they can reuse rockets My guess is the cost might be as little as a million ( or less ) for a satellite in orbit. That would be, what, $9 billion? That sounds like a lot, until you realize they can spread that cost over 2-3 years and have millions (if not billions) of people paying for internet. This would replace cellphone p…

The satellites are pretty low weight so it looks like the limitation is that only 20 or 25 can squeeze into a Falcon 9 payload faring. $20-25 million seems a reasonable guess for the cost (not price) of a reused Falcon 9 launch so $1 million a pop launch costs seem reasonable. But there's also the cost of the satellite itself. These are mass-manufactured and pretty low weight so I'm wildly guessing somewhere between $100k and $5m each.

Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed

#427

Post by [deleted] »

lettergram wrote: post #39
blurbleblurble wrote: post #13

Earlier quoted context omitted.

seems so expensive for such a short lifespan

I'm curious if they can launch multiple at once. I assume they can, and on top of that, once they can reuse rockets My guess is the cost might be as little as a million ( or less ) for a satellite in orbit. That would be, what, $9 billion? That sounds like a lot, until you realize they can spread that cost over 2-3 years and have millions (if not billions) of people paying for internet. This would replace cellphone p…

[deleted]

Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed

#428

Post by WiseWeasel »

nabla9 wrote: post #184
mrep wrote: post #160

napkin math (chemistry style): (4425 satellites * 23Gbps) / ((60,000PB of fixed internet traffic / 1 month [1]) * (12 months / 365 days) * (1 day / 24 hours ) * (1 hour / 60 minutes) * (1 minute / 60 seconds) * (8 bits / 1 byte) * (1024 Tera / 1 Peta) * (1024 Tera / 1 Giga)) = An astounding O(54% of global internet traffic) [2]! Obviously there are many many more variables in this [3]. Nonetheless this will be super…

More numbers to crunch: - Satellite with LEO orbit covers 1-2 percent of earth surface with 10 degree elevation. - Land occupies less than 30% of earth's surface area. Urban areas occupy less than 3 percent of the Earth's land surface. That's where the customers are. You have to divide at least by 100.

Urban areas already have high-bandwidth, low-latency internet service at more competitive rates, let alone 3-5 years from now. I'd think most target customers for this service are in rural areas, as well as those with a need for connectivity while traveling.

Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed

#429

Post by leonroy »

Seems a logical step for SpaceX. One of the biggest challenges facing Mars colonization would be internet connectivity over such tremendous distances.

A super cheap (relatively) satellite mesh network would be just the thing to handle Earth to Mars communications.

Getting out of left field here but could imagine the whole Solar System dotted with these. Add a few sensors to each satellite and you could start detecting and monitoring some pretty interesting metrics.

Re: SpaceX plans worldwide satellite Internet with low latency, gigabit speed

#430

Post by Symmetry »

duskwuff wrote: post #35
nthdesign wrote: post #15

Will this high number of low-altitude satellites cause a tracking and collision nightmare for the world's space agencies? Sorry, I recently finished "Seveneves" and I have space debris anxiety right now.

Dead satellites and debris in low altitude orbits will experience orbital decay and burn up in the atmosphere within a few years. High-altitude objects (e.g, at GEO) are more of a concern.

In GEO everything is going in the same direction at the same speed so there's really no danger of collision. It's all the satellites whizzing over Earth's pole in different directions that have resulted on the only accidental collision.
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