Good Idea? Not So Much...
DARPA has come up with some pretty good ideas in their time; the Internet is just one of them, and I'm sure there are others -- I'm just too lazy to do the research right now. Their job is to think "outside the box"; sometimes, though, they're so far outside of the box that they're not even in the same zip code.
CDR Salamander brings our attention to one of those times. Meet the "Cormorant", a hypothetical SSGN-launched UAV. Here's how it's described:
"The MPUAV concept envisions the immersible MPUAVs being housed and serviced in the ballistic missile launch tubes of the SSGN. They would be released from the submerged submarine and remain buoyant at the water’s surface until launched using two Tomahawk missile-derived solid rocket boosters. Upon mission completion, the turbofan engine-powered MPUAVs return to a designated retrieval point at sea, initiate engine shut down, and splash down to await recovery. During recovery, the submerged SSGN would deploy a remotely operated vehicle (ROV) to secure an in-haul cable from the SSGN to the recovery tether deployed by the MPUAV. The SSGN would then haul the MPUAV to its designated launch tube saddle mechanism, where it would be docked and retracted into the missile tube."
Now, I'm sure that something like this might be useful; intel from the air is a good thing. Despite what many people would think, the launching part isn't that bad -- since it will "remain buoyant at the water's surface" until launched into the air, the launching submarine would be able to clear datum before the rocket launch attracted the attention of every semi-alert military asset in the area. The big problem comes from the recovery: Assuming that an alerted enemy has been tracking the MPUAV, they would know where it had landed, and could reasonably assume that the submarine would come to that point at some time in the future to retrieve it. Since a submarine's stealth depends a lot on a potential hunter not being able to figure out where a submarine will be at some future time, it seems like this retrieval plan would be "Bad" on the Good/Bad scale from the standpoint of not getting shot at.
Remember, there are no stupid questions... only stupid people who ask questions.