I've always liked the idea of making the moon our Australia. Spend the money on 1960s era training and space material (I mean it worked then right), train condemned criminals, banish them from the planet. If they paid attention, they will survive, and live out the rest of their days on the moon. If not, well, they were condemned to die, and the cost to train and equip them would be relative pennies than keeping them imprisoned forever.
-OR-
We could do dirty dozen style recruitments put them on a static line, and push them out behind contested lines Crips Vs ISIS Vs Bloods battle Royal.
all positions volunteer... what guy with a life sentence wouldn't take that chance?
That idea has already been done in a sci-fi book.
Now if I could just remember.
(Moon as a penal colony)