No, there is no reason the Deep Impact cameras could not be used for astronomy, except perhaps those cameras couldn’t do anything of real value or interest for the cost it would take to operate them. Taking pretty pictures with a miniscule aperture? Oh wow.

Again, the Senior Reviews are constituted specifically to decide what is scientifically worth doing, as opposed to just what it’s possible to do.

The “story last week” about the fate of NASA planetary astronomy is not something uncovered by the investigative press, but just the tired blathering of Bob Zubrin (hosted by the Washington Times), who has, by now, lost most of his sense of reality, and sees the world through reddish-ochre-colored glasses. His blathering was promptly denied by NASA planetary science officials, who are actually actively planning missions that Zubrin claims aren’t being actively planned.