this development and test work in conjunction with the AEC, Sandia Laboratory, LASL, and the FC/AFSWP at Sandia Base. In short, LASL would build the "physics package" of a new weapon. This included the high explosive, the physical nuclear material, and the package. Sandia Laboratory would put the weapon in a case and install firing, fusing, timing, and safety systems, the electromechanical element. The AFSWC would track all of this new development for USAF use and drop test the new weapon designs. The AFSWC was also required to monitor the development work of aircraft contractors to assure compatibility of plane and bomb. Lastly, it provided support concerning special weapons to other USAF commands and support for full-scale atmospheric testing, as had the SWC. By September 1956, AFSWC included a group with three squadrons trained in the testing of atomic weapons (the atom bomb) and a group trained in testing thermonuclear weapons (the hydrogen bomb). AFSWC was organized into the following units: Research Directorate Development Directorate 4900th Air Base Group 4925th Test Group (Atomic) 4950th Test Group (Nuclear) AFSWC's Research Directorate became a focal point for USAF research in nuclear matters and advanced weaponry. Its mission was to "conduct applied research in the fields of nuclear weapons analysis, requirements and development, and to advise Air Force Special Weapons Center staff on nuclear research matters". In 1953 the Research Directorate began a weapons data-indexing project and maintained a technical library for all data on USAF contributions to the atomic energy program. The Research Directorate essentially led the charge in USAF efforts to conduct special weapons testing for weapons survivability and vulnerability. It also provided the groundwork for USAF interest in directed energy and weapons. The Research Directorate also conducted numerous studies on the hazards of neutron and gamma radiation exposure for aircraft crews both in the air and on the ground. For example, directorate scientists accompanied AFSWC's 4926th Test Squadron (Sampling) during nuclear cloud samplings taken at atmospheric tests in the Pacific and in Nevada. The Development Directorate's mission was to study, research, and develop nuclear weapons, weapons systems, components, and associated equipment for the USAF. In the early 1950s, the Development Directorate conducted numerous nuclear weapons studies focusing on specific target effectiveness and detonation conditions of atomic weapons. The Development Directorate was the AFSWC division working in conjunction with LASL and Sandia Laboratory as new bomb designs were developed. In terms