 He worked on the Manhattan Project from 1943 to 1945, developing keloid scars on his back due to radiation exposure, and witnessing colleagues next to him being caught in a laboratory explosion.After the war, Massie completed his PhD, which involved testing compounds for therapeutic activity.After completing his PhD and teaching for a time at Fisk University, Massie joined the faculty of Langston University in Oklahoma, where he taught from 1947 to 1953.