I don't understand the math. 800 satellites at 23 gbps seems to be able to provide 1 gbps to 18,400 connections at any given time. This seems to be many magnitudes off from what would be needed to have any impact. What am I missing?
Admittedly these numbers are all best case scenarios (except maybe the 1 TB average, that's probably generous), but even if you divide by 2 it's a decent number of people.
The issue is the antenna needs to be around 2 foot by 2 foot.
But, with autonomous cars people may want significant bandwidth in there cars. An hour or two of video a day seems reasonable especially if they can cache popular content.
Honestly, if they can get the price down this could be very profitable.
It depends on a country. Where I live, you can get unlimited 4G Internet for 15-30 eur/month (depending on a provider).
Edit: Maybe this has some answers: http://electronics.stackexchange.com/questions/11884/how-man...
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 from $60m to $10m in the near term. If we assume the satellite still costs $40m, that still cuts the total cost in half to ~$27/month @ 5%. Maybe they can mass produce these satellites and get them to $10-20m each, which would reduce it to more like $15/month.
Again all these numbers are pretty rough/best case scenarios, but even if we multiply them by 10 we could be looking at 1 gbps connections for $150-500/month. That could be cheaper than fiber infrastructure in a lot of places and still immensely useful in applications where fiber isn't possible (in a car, plane, or boat). That's also assuming 1 TB/customer. In many cases you may just buy the bandwidth in smaller increments at $1-10/gigabyte which is a few orders of magnitude cheaper than current satellite internet and comparable with LTE cell coverage.
The interesting part is what building 4425 satellites does to the economics of making satellites. Right now, most satellites are one-offs, or at most made in a series of 10 or so, handmade to exact specifications for maximum reliability and built for 25+ year lifetimes. This fleet is meant to be mass-produced and built to last a much shorter time, 5-10 years at most. I am very interested in just how low can they drive the cost of making a single satellite.
One of the best points in the discussion. This has potential to produce side-effects more valuable than whatever they were attempting to do. As in, they can fail in their overall goal but a ton of great things would come from success in this part.
You mean a satellite system can well end up your ONLY choice. If you're rural there are no choices besides dial up and satellite. Satellite is a reseller selling hughesnet.
For example, 23*4400 = 101Tbps, but I guess many of the satellites will end up above water, so maybe around 60Tbps. One cable by google did that for 300mil$ [1]
Maybe it is good for last mile connectivity, which is probably a good target, but only for less populated areas where LTE isn't available.
[1] https://www.extremetech.com/internet/231074-googles-faster-u...
Since the line of sight would often have things in the way. I'm assuming trees, bridges, and being in a garage would interfere with it.
https://www.faa.gov/about/office_org/headquarters_offices/at...
But this is more like cellular access points. You have a private channel.
http://www.alternativephysics.org/book/GPSmythology.htm
"The presence of Special and General Relativity effects has no bearing on the accuracy of GPS operation. In summary, it wouldn’t matter whether clocks aboard GPS satellites ran faster or slower than Earth’s clocks or even changed their speed each day. Just so long as the satellites’ clocks remained synchronised with each other and the time-difference relative Earth’s clocks didn’t become too large, GPS receivers would continue to calculate their correct position."
The reason that GR and SR have "no bearing" is because they've already been designed into the system...
From "Understanding the NAVSTAR" 2nd Edition, by Tom Logsdon ( one of the designers of the system ) the time-dilation is compensated through:
1. Off-setting the clock ticking-rate during manufacture of each satellite.
2. Applying a unique onboard corrective factor according to the eccentricity ( egg-shapedness ) of each satellite's current orbit. The latter is correction is constantly recalculated for each satellite.
Without these corrections against relativistic effects the accuracy would suffer by 14 nm after 24 hours ( without tick-offsetting ) and 100 feet or so per day due to orbital eccentricity.
Like a radio tower can service an entire town, but you need many many cellular access points.
What I don't understand about this though is the number of frequencies available to connect to all these satellites and how it might extend to ~300 million people (let alone a billion potentially).
The way they can make this work is if they
1) are targeting traditional satellite internet customers (ships on the sea, commercial aviation, etc) and
2) integration with 5th generation mobile networks trough wireless network virtualization. Mobile network provider can sell a service where traveling customer pays extra for connection that works in the middle of nowhere. When the device is within normal cell network or WiFi, connection goes trough those networks, when they are sailing with their yacht, it can jump from the picocell in the boat or backpack to the satellite network. At any given time there may be millions of customers who pay little extra for coverage and just few tens of thousands who actually use it.
That made me stop and think for a bit...
(Gah - and don't you hate it when people stealth-edit their comments and make you look insane? For the record, the parent originally said "commercial aircraft carriers" instead of "commercial aviation". I may be insane, but there's a completely plausible explanation for this comment thread and it can't be used as evidence of my lack of sanity, ok?)
I've got a 5.8GHz "patch antenna" for FPV video from a quad copter which claims 12db gain - but I've got no idea what shape it is inside (it's small, maybe 70 or 80mm square, but it's a literal "black box" with an sma connector on it from my perspective).
This could be a big deal for the huge under-served population in rural America and in developing countries. Incumbent telcos would have to have service at least as good/cheap as SpaceX's internet service to stay in business. I hope they introduce a low-cost, relatively low bandwidth plan that's accessible to the world's poor.
But the world's poor have internet connectivity, 3G/LTE is cheap and widely available. Don't go by US prices for data. Cellular plans here in India are cheap.
Of course you generally need to provision for peak bandwidth rather than average so these numbers aren't even close to accurate but I think it's a rough explanation for why you don't need to fully provision every link.
I';; also counteract may own argument as to numbers with the idea that 16 million people could really mean 16 million households if they watch the movie together :-)
Working for a CDN, we see our POPs gets about 4x traffic at peak compared to low times.
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°"
Um, what? Of course you can.
We have weather satellites in this exact orbit right now.
Source: am outdoor robot researcher.
At some point as we developed world wide communications, laying down long distance fiber became cheaper than deploying communication satellites, and the existing satellites had enough capacity for the demand at the time.
We stopped shooting up sattelites, but we developed much better wireless technologies (e.g. MIMO) down on earth, and SpaceX now has the means to deploy those in space and undercut the competitions offerings that is still being used heavily for specific use cases (e.g. broadcasting, marine, etc applications)
It doesn't even have to be cheap, it just has to be cheaper than the competition. It's not quite world changing, but it's still a massive business (i guess) and would provide spaceX with some steady revenue stream. If it eventually becomes cheap enough for mass market that's just icing on the cake.
Also note that any competition also will have to pay SpaceX for deployment, so SpaceX wins no matter what.
Perhaps dollars are an overstatement, but your numbers are also for a best case scenario, when you have an application where you need to send data infrequently, in bulk, in an area with good coverage (not at sea) and no guarantees.
I guess the numbers depend on what "final deployment" means. Presumably more satellites with higher bandwidth.
This is some of the rationale behind data caps. While you can still exceed the available bandwidth if all your customers get on and use their connection to the max, a data cap forces your customers to meter their usage out over the month and reduce the impact of this concurrent usage pattern.
what if everyone withdraw their money from the bank at the same time?
what if everyone flushes their toilets at the same time?
Even if that's true they've effectively subsidized their rocket business and gained more experience through a greater number of launches. Often Elon is trying to kill more than one bird with every stone he throws - maybe he knows he'll need a solar network to support a Mars colony. This is how he gains the tools, people and experience to eventually roll it out.
Why do you think he wouldn't do the same here? He knows everyone hates existing telecoms. He's trying to create a better alternative.
Not true everywhere. I'm paying < $40/month for a 100 MBit connection and I don't hate my telecom.
It is directed towards middle of nowhere areas where nobody provides fiber.