That could be potentially very devastating if they were relying on solar power alone. You could pretty much knock out all their base defenses and production in one go. And they'd have no defense against it either, ... other than to not rely exclusively on solar power.
Hmm, come to think of it, that really makes solar power fairly useless. It'd also be a pain to be constantly losing your EDWARD satellite or whatever else you have up there. And to shoot down the other colony's spaceship? That just doesn't seem very Outpost like. They're fighting for the survival of the human race. Shooting each other's spaceships down seems like a very bad idea. You're pretty much dooming everyone to die. Mind you, I'm still thinking Outpost 2 and not OP3.
In short, I think the idea would unbalance the game too much, and I don't see how you could rebalance something like this.