Dan Dawson remembers how difficult it was to run with a backpack nuke. Today, visitors to the U.S. government's National Museum of Nuclear Science and History in Albuquerque, N.M., can get their picture taken in front of a SADM parachute container. Special Atomic Demolition Munition Adam Rawnsley is a D.C.-based writer covering technology and national security. David Brown is the author of Deep State: Inside the Government Secrecy Industry. http://www.foreignpolicy.com/articles/2014/01/29/the_littlest_boy_cold_war_backpack_nuke