SpaceX plans worldwide satellite Internet with low latency, gigabit speed

On the internet you need to know the receiver and sender of a message, otherwise you have no idea where it's going and the best method to from there is to use very inefficient methods.

HTTPS and IMAP over TLS already achieve MITM-resistance, as long as you verify the certificate.

With TLS (and SSL to some extend) you can't snoop on and censor data, not without compromising the sender (assuming you trust their certificate explicitly).

1. Uplink/downlink. This is the most primitive and I understand still the most common. You RX, strip the carrier off, mix it with a new carrier, amplify it and send. There is no intelligence other than the uplink and downlink frequencies. Bandwidth of both of these is pretty wide. Ergo, latency is minimal, power efficiency is high. The satellite doesn't have any idea what the signal means.

2. Decode/retransmit. This you need to RX it, strip the carrier out, demodulate it possibly thousands of channels individually spanning a massive bandwidth, intelligently decide what to do with it while buffering it, mix with one of many new carriers, amplify, retransmit. Latency high, power efficiency low.

The latter requires some serious routing power which isn't necessarily available either cost efficiently or reliably of the shelf. Getting something like that which is rad hardened isn't likey to succeed and you can't just launch three redundant core 2's to do it like Dragon.

Imagine launching a radiation hardened 4G base station. That's a good analogy.

Thanks for working this out. This matches with Musk's stated goals for the project from January 2015 ("the majority" of internet traffic): https://www.youtube.com/watch?v=AHeZHyOnsm4&t=2m40s

>The focus is going to be on creating a global communications system. This is quite an ambitious effort. We're really talking about something which is... in the long term it will be like rebuilding the internet in space. The goal will be to have the majority of long distance internet traffic go over this network, and about 10% of local and business traffic. Probably 90% of people's local access will still come from fiber, but we'll do about 10% of business and consumer direct, and more than half I think of the long distance traffic.

>As you guys may know, the speed of light in a vacuum is somewhere between 40-50% faster than in fiber. So you can actually do long distance communication faster if you route it through vacuum than you can if you route it through fiber.

>And you can also go through far fewer hops. Let's say if you want to communicate from Seattle to South Africa. If you look at the actual path that it takes it's extremely convoluted[1]. It will follow the outline of the continents. It will go through 200 routers and repeaters, and the latency is extremely bad. Whereas if you did it with a satellite network you could actually do it in two or three hops. Well maybe four hops; it depends on what the altitude of the satellites are, and what the cross-links are.

>Let's say at least an order of magnitude fewer repeaters or routers, and going through space at 50% faster speed of light. So from a physics standpoint it's inherently better to do the long distance internet traffic through space.

[1] https://personalpages.manchester.ac.uk/staff/m.dodge/cyberge...