Project Orion is one of the stupidest, most wonderful ideas ever conceived in America.

_Project Orion_ by George Dyson is a decent book about the project. In addition to the historical narrative, it has some good and detailed (for a popularization, anyway) explanations of how the technology was supposed to work.

An interesting story on Atomic Spacecraft here http://www.damninteresting.com/?p=679

Come on, Project Orion wasn't stupid.

...for certain values of "stupid."

We could build an interstellar spacecraft if our society took science seriously.

kewl.