It's tough to defend a new space policy.
Now, if a robot is going to extend the HST's lifespan, it will certainly do a lot of good to unmanned technologies in space rather than the human presence out there.
The Martian rovers successes are also a way of showing that wheeled robots, with improved technologies, could travel around Mars for months if not years, go down craters, climb steep cliffs, while analyzing very small rock fragments, witnessing dust devils and Sun eclipses by the moons and analyzing samples that could hint at some microbial life.
Every day, a new landscape, new questions, new answers.....all with a few robots and at a fraction of the cost of sending humans to the same place.

Raoul