It's the Pentagon.
Remember the scene from "Broken Arrow" when Frank Whaley suggests that they tell the truth, and everyone laughs?
I wouldn't be surprised if a) there was super secret spy stuff on the satellite, b) it IS a test of an anti-satellite defense system, and c) the hydrazine poisoning story is bull. The satellite would probably have landed harmlessly in the ocean, which is NOT what the Pentagon wants.