Your a and b are unfortunate consequences, not deliberate objectives.

What NASA does is Research and Development: always trying new technology, making things lighter, more heat-and shock resistant. The problem is: time passes and big projects see improved technologies coming in before the experiment has a chance to start. Freeze it or not? That's the hard part.
And there was space exploration: that's why FBC was implimented by Goldin; under his administration, Mars was visited again, asteroids were studied, new technologies were tested (deepspace 1) etc...That was space exploration as I understand it.
Will it go on?
Raoul