Interesting toy here
I have no doubt that this CAN be built - start with some very talented aerospace engineers and add a bottomless checkbook based on "National Defense Needs" = first flight 3rdQ 2009 or so.
It may also not be all that easy to shoot down, either. First you have to detect it - heat seekers NG, not a jet, nothing gets hot enough to interest a heat seeking missile. Radar, add some stealth technology, poof, it's gone off the radar screen. Optical - mirrors, adaptive camouflage, decoy drones perhaps.
The fact that it is designed to connect up on station means parts can be replaced as needed, fly up a new module, slot it in, fly the old one back down for service, platform is still available for use, could continue indefinitely.
Even if you could "acquire" it (track it for targeting purposes), if it were over international waters and got shot down, the owners might have a few things to say about it, and remember the owners of this particular item have a LOT of firepower available to them and become very cranky when their toys get damaged by third parties.
What I really want is a solar -powered airplane that I can fly across the whole ocean in! Doesn't even have to be really fast, as long as the propulsion power is free. Where can we put the seats? What's the in-flight movie?