Really nice, nicely done.
Let me give you my perspective on the Space Shuttle. I love NASA and what they have done with the Shuttle and Apollo before it. However, the time for those has passed and we should not replace them with anything that takes humans into space. Ever.
Space is simply not a human thing. We are far too fragile to survive out there for any meaningful duration, and I think the space shuttle proved that fact. Over the last 30 years, we've accomplished launching a telescope, several satellites and some erector sets from the Shuttle. Furthermore, the Shuttle has enjoyed a 1 in 25 chance of death -- meaning you are 365,000x more likely to die on a Shuttle than a commercial flight.
I'm not trying to diminish the accomplishment, I think putting humans in space is hard. What I am trying to ridicule is the idea that we should keep doing it. It really is too expensive for where it gets us. We cannot do much with the limited opportunity we're given to be in space, and to give us more would be cost prohibitive and risk too many lives.
No, something else needs to take space from here. Either it will be artificial intelligence or some sort of engineered organism that can do it. We're the first species in the history of the world that can create a being that can explore for us. It's time we start focusing on that. Automata will get us to the next level, not more Shuttle-like stuff.