Not to beat a dead horse here, but this article about the Space Shuttle is brilliant :

In the thirty years since the last Moon flight, we have succeeded in creating a perfectly self-contained manned space program, in which the Shuttle goes up to save the Space Station (undermanned, incomplete, breaking down, filled with garbage, and dropping at a hundred meters per day), and the Space Station offers the Shuttle a mission and a destination. The Columbia accident has added a beautiful finishing symmetry – the Shuttle is now required to fly to the ISS, which will serve as an inspection station for the fragile thermal tiles, and a lifeboat in case something goes seriously wrong.
. . .
To the uneducated mind, it would seem we could accomplish our current manned space flight objectives more easily by not launching any astronauts into space at all – leaving the Shuttle and ISS on the ground would result in massive savings without the slighest impact on basic science, while also increasing mission safety by many orders of magnitude. It might even bring mission costs within the original 1970′s estimates, and allow us to continue the Shuttle program well into the middle of the century.

But NASA dismisses such helpful suggetions as unworthy of its mission of ‘exploration’, likening critics of manned space flight to those Europeans in the 1500′s who would have cancelled the great voyages of discovery rather than face the loss of one more ship.

Of course, the great explorers of the 1500′s did not sail endlessly back and forth a hundred miles off the coast of Portugal, nor did they construct a massive artificial island they could repair to if their boat sprang a leak. And we must remember that space is called space for a reason – there is nothing in it, at least not where the Shuttle goes, save for a few fast-moving pieces of junk from the last few times we went up there, forty years ago. The interesting bits in space are all much further away, and we have not paid them a visit since 1972. In fact, despite an ambitious “Vision for Space Exploration”, there seems to be no mandate or interest in pursuing this kind of exploration, and all the significant deadlines are pushed comfortably past the tenure of incumbent politicians.

That last part goes back to what I was saying in my previous post. There have been plenty of chances over the last twenty years for our leaders to make modernization of the manned space program a priority, but that takes the kind of political courage that’s nearly impossible to find these days. What’s especially disappointing is the missed opportunity in the wake of the Columbia disaster. The President could have ordered the shuttle fleet permanently grounded and pledged to spend whatever it takes to rebuild our space program from scratch^{[1]This is the ultimate irony. Imagine the billions of dollars in government handouts the President could have given his corporate cronies in efforts to rebuild the space fleet.}, but instead he offered comforting words and saved his cash for more important things like trying to bribe the Turkish government into joining the Iraq war.