An Orion drive actually scales pretty nicely. As I recall, a city 20 miles wide planted on top of a big metal plate was just about the sweet spot. Mostly this w

An Orion drive actually scales pretty nicely. As I recall, a city 20 miles wide planted on top of a big metal plate was just about the sweet spot. Mostly this works because it is easy to make a bomb with more yield without making the bomb larger.