I first heard about Project Orion in college when I read John McPhee's "The Curve of Binding Energy. Launching 200-ton spaceships by dropping atomic bombs out of the bottom. Oh man!
Jerry Pournelle, who is still a supporter of it, once wrote a novel, "King David's Spaceship," about it.
If we had gone with it, we'd have colonies on the Moon...Mars...spacestations. But as usual, the people in the government are idiots.
Posted by Bob Wallace, who is still annoyed he has no flying car and a blaster.