There are multiple satellite ISP companies and there are even Blockstream satellites that are fully dedicated to broadcasting Bitcoin blocks.

I'm not sure you really understand what a double spend is. It's not actually a big deal in the real world. An attacker capable of double spending is simply capable of reversing blocks, therefore reversing transactions.

So, for example, an attacker could buy a house with BTC, and then when the papers are signed, reverse the transaction to get their BTC back. But in the real world, the victim would just go to the police and get their house back.

The only plausible "big league" threat would be a government investing billions in ASICs to perform a 51% attack and grind the network to a halt. But the Bitcoin community would probably quickly move to a new Proof of Work algorithm and render their ASICs worthless.