Space

I came across the website of the Columbia Accident Investigation Board [www.caib.us] and started reading their report [pdf]. It's kinda large at 248 pages, but so far it's been an interesting read - going over the history of NASA and why the Shuttle was built.

A few years ago I read the book At the Edge of Space: The X-15 Flight Program, which covered the X-15 program. It was around before the Mercury missions at NASA and I thought it was very successful. They reached over 350,000' and speeds greater than Mach 6. It seemed like a logical way to reach orbit, but it was canned and money was diverted to NASA.

The X Prize project is underway with many teams trying to put a few people into low earth orbit. Quite a few are taking the same approach as the X-15 did. It seems like the logical way to get into orbit - you take a plane up and can fly it down (unlike the Orbiter which is a large glider).