CROSSROADS and the 58th Wing of the Fourth Air Force was designated
Headquarters, Task Group 1.5 (Provisional).° From this organization
came the staff for the test group.
The 509th Composite Group and
Roswell Army Air Field transferred to the Fourth Air Force from the
Second,
IT.
It had dropped the two atomic bombs on Japan during World War
The S8th Wing then transferred from March Field, California, to
Roswell,
There an intensive training program was instituted.
Each unit
concentrated on its special mission, with the highest priority being given
to the bombing aircraft unit, the 393rd Bombardment Squadron.
Bombing
ranges near Albuquerque and Alamogordo were used heavily and Clovis Amy
Air Field as a satellite trainiiig field for Task Group 1.5 (Provisional)
where the world's first atomic cloud sampling was in preparation with
drone aircraft,
1
Sampling CROSSROADS
Operation CROSSROADS saw the beginning of Air Force atomic cloud
sampling with drones because of the unknown dangers.
Manhattan Project
sampling requirements included tiny portions of the debris contained
in the atomic cloud which represented what was actually contained in the
cloud,
One of the biggest worries for the scientists at that time was
that fractionatj{on would take place,
Fractionation was thephysical
change in the distribution of debris particles collected andcould
give false impression of what the cloud contained,
"with no
experience to fall back on," William Rubinson, a Los Alamos scientist,
wrote, "All that one can do is to collect as many different samples in as
many places and as many ways as possible, and devise what means he can
h
SWEH~2-003h
4>
“(see