But doesn't the Faustus solar panel array spin because there's some sort of motor where it attaches to the main body?
No, it spins because it's a rotating subsystem.
Which is the same reason the Knossos rotates...
[Read: It's a game. Cool>>physics.]
Battuta: Yeah, I pretty much knew that you know all this rather well... a wheel would keep spinning, but two halves of a wheel wouldn't without something keeping them together.. obviously. I just interpreted the question about what's keeping the parts rotating in the sense that "what is the force that keeps the parts on their circular paths" rather than what's keeping the rotation going... I think I took it for granted that the rotation itself wouldn't need anything particular to keep it going any more than any other space ship of comparative size.
By the way. For all we know, it could've been rotating since it was built. That doesn't necessarily mean that the node-activating/generating mechanism had been activated. Kinda like you can have a car's engine running idle while the transmission doesn't move any torque further through the drivetrain. The NTC Trinity could have just put the gear on, so to speak.