Program 4. The objective of tnis program was to determine the extent of chorioretinal damage caused by exposure to a high altitude, high yield nuclear detonation at distances from zero to 300 nautical miles from ground zero. Program 5. This program was designed to determine the effects of nuclear weapons on aircraft structures. Nuclear weapon delivery by manned aircraft is often affected by the weapon's blast and thermal effects on the delivery aircraft and by nuclear radiation on the crew. Test data have in- dicated that blast input and skin temperature rise can be predicted within satisfactory limits, but that predictions of aircraft response to the blast and computation of thermal input is much less reliable. In order to perfect delivery tactics where safety margins are critical, manned B-52D, A4D-1, and FJ-4 aircraft were to fly several missions each, collecting data on the results of various inputs. Program 6. This program was to study effects in four categories: 1. Electronic equipment located at various distances from the zero point was to collect data to determine the feasibility of using the electromagnetic pulse from a nuclear burst for long and short range detection, and to study the fireball and nuclear cloud with radar for determining ground zero and yield. 2. Investigations were to be undertaken of the fonization effects of high altitude detonations, particularly as they might effect communication systems dependent on the ionosphere for propagation. 3. Investigations were to be made of the deleterious effects on fuzes and their components of gamma rays and neutrons from nuclear explosions. 4. On the underwater shots, experiments were to be made to determine the feasibility of using nuclear explosions for clearing of mine fields. Program 8. This program included the evaluation of laboratory methods of scaling thermal effects with weapon yield. Probably the most important part of the program participation was the investigation of the little known thermal phenomena and the parameters which have a direct relationship on the damage-producing thermal effects from the fireball of high altitude detonations and the prediction of those parameters for other heights and yields. Included was to be the photographic measurement of the fireball radius vs time history of high altitude detonations. Also, thermal measurements were to be made from a subkiloton device. Program 9. This was a general support program designed primarily to provide photographic coverage for all interested TU-3 projects. Two numbered projects. 9.2 and 9.3, were assigned the mission of providing balloon and missile carriers, respectively, for the three high altitude events. 1.4 SANDIA CORPORATION Program 32. The mission and designed purpose of Program 32 of OperationHardtack for the Teak and Orange events was to measure pheno- mena of interest to the Atomic Energy Commission, to develop and test instrumentation techniques compatible with phenomena associated with large nuclear bursts at very high altitudes, and to measure effects of interest to the Department of Defense. The measurements of particular interest to the Atomic Energy Commission pertained to the phenomenology of the warhead. 21