We never know when or from where the next surprise or exciting answer is going to come. That's what keeps things going. The least favorite part I think is having to constantly lobby for money for research and the resources to do things in the space program. I think it's essential that we have a space program. Technologies that spin off that are going to help us in the long run.
Moneys are tight and space research is expensive, but it's a unique tool.
So you spend a lot of time trying to convince the government to spend money on these various areas. In part it's good because it allows you to think about why are you doing what your doing, but after a while, if you have to keep explaining it too often, you spend too much time doing that and not enough time working on the actual project and thinking about the science and what your trying to study. So that becomes frustrating. There's just too much to do. Spare time is for going back to what actually got me interested in science in the first place.