Well, political reasons generally, and the Partial Test Ban treaty in particular. It turns out there's really good reasons to limit the number of bombs detonate

Well, political reasons generally, and the Partial Test Ban treaty in particular. It turns out there's really good reasons to limit the number of bombs detonated in the atmosphere, and for that matter the number of bombs, period. https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...