[Wolfman77]

Null: I thought they needed the matter-antimatter engines to run the cloak. Even so why not store the helium while you are cloaked? Of course it seems rather odd as the cloak is supposed to absorb energy, why does it need energy to run?

SJ: yes, the reactor would absorb gamma rays to create power, I just didn't think it needed to absorb every single one. Thought they might have a few leak out though, since some of those high energy ones can pass right through the Earth and all, but I suppose those would be hard for sensors to detect. My original thought was that the reactors could absorb them up to a certain wavelength (or down to as more acurately discribes higher energy EM waves). After this the shielding (lead wall sense) would absorb the rest, but not perfectly.

Then again if the cloak is absorbing energy, or even just deflecting it back to the ship, couldn't that be used as a temporary power source while cloaked? Assuming that some, barely detectable, energy is lost, then its just a matter of sensitve enough sensors to pick it up. Or waiting untill they need to start their engines for loss of power after a few hours or something. I suppose this could be called the exhaust.