I was going to create a topic for this, but this thread is just as appropriate.
The Space Shuttle, officially the Space Transportation System (STS), is the fruition of an idea whos time has come--and gone about twenty years ago. The concept behind it was a spacecraft that could be launched into orbit by rocket, and then glide back into the atmosphere to a landing like an aircraft, and be reusable. It was conceived that such a spacecraft would be more feasible to use than conventional expendable rockets and space capsules. Just as importantly, it was a space project by which the US could demonstrate its technical prowess to the world (read: the Soviet Union). "If we can conceive it, we can make it" was the inspiration, not unlike Kennedy's earlier, "because it's there" raison d'etre for the manned moon missions. So, the Space Shuttle program was kicked-off, the first shuttle was launched ito space, it came back and landed as expected. It was spectacularly successful. Soon, more shuttles were built, and shuttle launches became so common that they ceased to be aired by the major television broadcast corps.
The problem with the StS is that it's ends, rocket launch/ aircraft return, and semi-reusability, are irrelevant and incongruent to the larger, international space program objectives: duration research in space, the return to the moon, and a manned mission to the planet Mars.
The STS is so exceedingly complex that any ideas of cost-effectiveness were thrown out of the equation even while it was still being developed. It's been cheaper and much more reliable to use conventional rockets to deliver payloads to space. Science experiments are better handled by the International Space Station (ISS) than by the STS, which was not designed to stay in orbit for much more than a week.
The STS is in effect a very expensive, highly unreliable freighter that has proven to be woefully inappropriate and obsolete for the purposes it's being applied to. It is the white elephant of the US space program.
A few weeks ago the New York Times reported that the Space Shuttle program is going to be phased out in favor of more conventional rockets and space capsules. NPR broadcast a similar story today.
Here's a pic from the NYT story showing what the next generation of spacecraft might look like.