Amos Zeeberg, the person you should pester (hopefully ineffectually!) when I'm not being nice to you in the comments, has an interesting opinion piece up lambasting the Shuttle program. Here are the numbers which jumped out at me (I knew the broad outlines, but nice to have precise numbers):
The most important thing to realize about the space shuttle program is that it is objectively a failure. The shuttle was billed as a reusable craft that could frequently, safely, and cheaply bring people and payloads to low Earth orbit. NASA originally said the shuttles could handle 65 launches per year; the most launches it actually did in a year was nine; over the life of the program, it averaged five per year. NASA predicted each shuttle launch would cost $50 million; they actually averaged $450 million. NASA administrators said the risk of catastrophic failure was around one in 100,000; NASA engineers put the number closer to one in a hundred; a more recent report from NASA said the risk on early flights was one in nine. The failure rate was two out of 135 in the tests that matter most.
To take the intangible value of human life out of the question, if we were going on the cheap then a 2 out of 135 failure right might be understandable. But we weren't. The shuttle cost a lot. To whom much is given (in dollars) much shall be expected. It didn't live up to the expectations. In an unrelated vein, I wonder if the aging of the earth's population is going to put a damper on space exploration in the short term. The explorers of the future are more likely to be de facto intelligent robots.