Since Operation Crossroads depends for its success upon the photographic record that was made of the explosion of an atomic bomb, the Air Photo Unit, designated Task Unit 1.52, finds itself one of the most integral divisions of Task Group 1.5.

The history of the unit goes back to 10 January 1946, when Col. P. T. Cullen was told in Washington he was being assigned to the staff of Vice Adm. W.H.P. Blandy, Task Force 1, and that he had until 15 April to assemble, organize, equip, and train an organization capable of taking more feet of correctly-exposed film in a shorter space of time than any organization in history. In less then three months, that organization was to be operational on far-off Kwajalein, in the Marshall Islands.

That was when the bomb dropping date was 15 May. Later, the date was postponed until 1 July, but by the time of that postponement, much of the ground work already had been laid, many of the personnel already were at their advance Pacific base, and enough training flights flown to prove that the unit could have been ready and operating on the original date.

Activation of Task Group 1.5, and its various units, was made effective at 0001 hours, 21 January, with verbal instructions from Brig. Gen. Roger M. Ramey, commanding general of the 58th Bomber Wing, and later confirmed in a letter from headquarters of the Continental Air Force dated 29 January.

In the meantime, Colonel Cullen already had begun picking his key men, orders had been placed for 10 B-29s to be especially modified for use as photographic planes, and headquarters was being set up at the Roswell Army Air Base.

Men who had been screened for essential MOS qualifications began to trickle in from all air fields in the nation. Problems of billeting, mess, transportation, communication, and supplies grew with every arrival, but before 1 March, most of these were being whipped and the unit began taking shape as a tightly-knit organization. Arrival of the modified planes from Tinker Field, Oklahoma City, added training programs to the schedule, and transportation of men in small groups to the advance base on Kwajalein meant the screening of men needed at the two bases so that each could operate with efficiency.

On Kwajalein, bad weather and forecasts of worse, lack of adequate buildings for headquarters and billeting, and finally the delayed date that was such a blow to morale for those who thought the assignment might be completed quickly and they could return to their home stations, only added to the problems that had beset the organization from the first. However, these were ironed out, and long before A-Day, rehearsal missions were functioning with a smoothness believed impossible weeks before.

There is more to the organization than installing cameras in planes and circling a target area while trained photographers take pictures of an exploding bomb. All units had to have pictures taken for historical and record purposes, both movies and stills. A huge laboratory, capable of handling all this film, as well as the great amount exposed on Able Day, had to be set up-and this meant whipping the problems of tropical heat and the shortage of adequate water and power.

Above all towered the need for security. Since the atomic bomb was America's top secret, and one piece of all that exposed film falling into unauthorized hands could give away information that had been guarded with such great care and expense, elaborate precautions to guard against such an accident were taken.

Personal cameras were forbidden after 1 May, and all personal photography was forbidden. Every foot of movie film and every sheet of still camera film issued for official photography was checked and double-checked to see that each piece was accounted for. Every negative, aerial as well as still, was screened and classified as to whether it contained restricted information before a print was permitted or before it could be viewed by persons not authorized to view restricted material.

How well this organization has been formed must be judged by the amount of work accomplished, and in the tons of film that have been exposed and which are being placed in the hands of military heads and scientists for study. Every member of Air Photo Unit, whether he operated a camera from a plane or helped with the less-glamorous clerical work at the Kwajalein base, can feel he had a hand in providing this photographic report that will prove what the world's most potent explosive does when it is released above a fleet of vessels that until a year ago were masters over all their guns surveyed.