Firstly, its not possible to "ignite" Saturn with a space probe, or a nuke, or several hundred nukes - of any kind. I refer the honourable readers
to comet Shomaker-Levy 9, and the overall effect and force of explosions that occurred when it hit Jupiter.
Secondly, unless the shuttle was armed with some missile that was capable of "impulse" drive or some other such sub-light speed, theres no way
anything that it could take into space could make a difference to a comet so far out in such a short space of time - if we had that kind of engine we
wouldn't be sending 7 people up vertically strapped to the equivalent of a small hydrogen bomb, would we?
Whats more probable is that this comet has a unique composition, possibly it has a hollow core and on its outward leg it accumulates an awful lot of
ice and dust which forms a shell over the core and prevents outgassing until the outer shell is stripped away by incresing temperature and the solar
wind as it approaches the the sun and then the object starts to outgas massively, hence the sudden "flare" - a bit like a meteor hitting the earths
atmosphere.



That just makes too much sense to be true. 
I really wanted to see it for my self.
Someone please come EMP our power grid, I don't have enough gas to drive out east right now. lol 