Dan Gillespie was a twenty-two-year-old member of the Special Engineer Detachment in Los Alamos who worked on developing the chemical processes to produce the initiators used in the Fat Man bomb. Specifically, his job was to figure out a procedure for depositing a coating of polonium onto the surface of the beryllium sphere, while maintaining a consistently low level of neutron emission. After the war had ended, Dan received the following letter from J. Robert Oppenheimer thanking Dan for his service at Los Alamos.
October 15, 1945
Dear Mr. Gillespie,
This letter is to acknowledge your contribution to the development of the atomic bomb. The striking success of this project was made possible by the work and sacrifices of the military personnel. According to your group leader, you are to be especially commended for seven months’ work on one of the most urgent and secret parts of the project. Starting without any special training in radiochemistry, you have done excellent work in this field. Your diligent work during the most trying times and under the difficult and dangerous conditions that the urgency of the work required was an important factor in bringing success to the project. Your ability in electrochemistry and in general scientific work has made you a very valuable research man. It is hoped that you will continue in scientific work. This letter may be used as a reference if you so desire.
J. Robert Oppenheimer