- last post: 01.01.0001 12:00 AM PDT
I think it could be:
A defence dome node (to shield from the halo's pulses),
A massive cannon (referance to the "giant slingshot"),
A giant flashlight (no kidding, maybe an indicator to where the ark is),
A halo itself within earth,
A time travel device,
And finaly a slipstream generator (kind of like a tradelane in Freelancer),
Please converse and add your own theories.