National Museum of Nuclear Science & History
Armstrong worked at the 200 West and 300 Areas at Hanford during the Manhattan Project.
Gus Essig began working on the Manhattan Project in May, 1946 in Dayton, Ohio. Essig was selected to work in the highly classified initiator program and spent several months at Los Alamos learning how to design and construct initiators.
Bernard Sesko served in the Special Engineer Detatchment (SED) at Los Alamos during the Manhattan Project.