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).