[ceejayoz]

Iridium currently offers a handful of megabits at best, doesn't it? Starlink's loading 20 Gbps on each satellite, and has successfully tested up to 610 megabits on a connection with a military plane. (https://spacenews.com/spacex-plans-to-start-offering-starlin...)

> Every cost estimate made by people in this industry say it will be much higher than geo to deliver a bit.

I'm not clear on whether you're referring to the ground station, the satellite constellation, or the cost of service here.

That said, industry laughed at the idea of reusable rockets, and Blackberry thought Steve Jobs faked the iPhone pre-release. Industry estimates have been known to be badly wrong.

[shaklee3]

The ground system is what will make or break starlink. Every phased array antenna to date is at a price point that would put starlink selling exclusively to enterprise customers. This means consumers won't be able to get it unless you're in the 1% and living very remote.

SpaceX will not realize 20Gbps per satellite in useable bandwidth. It's more like 5Gbps.

http://www.mit.edu/~portillo/files/Comparison-LEO-IAC-2018-s...

[ceejayoz]

OneWeb claims to have cracked that, for a price point of $200-300. https://spacenews.com/wyler-claims-breakthrough-in-low-cost-...

Even if it winds up being more expensive, you might see a neighborhood getting an antenna and distributing it to a group of houses.

> SpaceX will not realize 20Gbps per satellite in useable bandwidth. It's more like 5Gbps.

Based on guesses made prior to the first launch of production hardware, and speculative guesses on the number of SpaceX ground stations? Your slides are from 1 October 2018. The first batch of production hardware went up 24 May 2019.

[portillo]

I am the author of the slides/paper. The analysis was done with the best data available at the time, but I am interested in knowing what parameters you think are off / have changed substantially since then.

I can say that the mass and volume of the satellites has changed quite a lot, and therefore the number of rocket launches required is pretty off in the paper. But I have not seen much info to invalidate the rest of results.

[shaklee3]

Correct me if I'm wrong, but I thought the mass estimates increased? either way, that should only affect how many that can launch at a given time. I didn't think that number had changed appreciably either.

[portillo]

In their original FCC filing, they were estimating 386 kg per satellite. The ones launched in May were 227 kg each, and those last month 260 kg (they added the Ka-band antennas).

I am not sure how much heavier will the satellites be when they integrate the ISLs (if they do), but I believe that in any case they will be under 330 kg.

[shaklee3]

These are not guesses. These are calculations based on FCC filings with things like EIRP, PFD, etc, all included. SpaceX cannot simply transmit hotter than they filed for just because the filing is old.

If anything, they're worse than those calculations since there's no ISL, and there were reported propulsion system problems.

I personally can't see a neighborhood going in on satellite internet since they still need to transmit between each other, which would mean more equipment.