Operation Plumbbob [wiki] was a series of nuclear tests conducted in 1957 in the desert of Nevada - it was the biggest and longest (not to mention most controversial) nuclear weapons test series in the US.
The military was interested in knowing how the average foot-soldier would stand up, physically and psychologically, to the rigors of the tactical nuclear battlefield.
Studies were conducted of radiation contamination and fallout from a simulated accidental detonation of a weapon; and projects concerning earth motion, blast loading and neutron output were carried out.
Not surprisingly, as part of the test, the military was also interested in finding out whether blimps could be used to carry nuclear weapons!
Link: Article at Fogonazos | Nuclear Weapons Archive - Thanks Aberron!