Blighty gets DARPA cash to put sat-phones in satellites

Vlans

As long as the management vlan is kept secure. Whats in these sats, Cisco, Linux? If the sat/phone/modem connects to the console you could do a password recovery ;)

@Security hole

Probably some kind of a hole. But any halfway smart developer will have comms encrypted with some massively long key, so more of a theoretical problem than a real one.

I do like that System F6 idea. Only trouble is that with wireless transmission between sats, you're at the mercy of a notoriously harsh EM environment, even without the added possibility of aggressive strikes by "interested parties". Granted, a regular sat will need to power down its receivers during a solar flare too, but a regular sat is usually a long way away from any other sats. When you've got a cluster of sats flying relatively close, being unable to swap position data with neighbouring sats is a bad place to be. There's also the problem that the more sats you've got, the more chances there are of one failing terminally. Sats don't lose orbit immediately, so the remaining sats are faced with the issue of how to avoid the bricked sat in their midst.

swam vs integrated

I could see that if 1 portion of a swarm went down, that's better than a portion of a large integrated satellite. However you would need each mini sat to have it's own navigation and propulsion etc to keep it in the proper orbit etc. That all adds to complexity and increases failure rates. Seems like a mixed bag. A better approach might be removeable/ejectable/turn-off-able modules on an integrated satellite that could be replaced by a follow up satellite. Either wirelessly nearby, or by a robotic replacement of the failed module.