observations focused on long wavelength radio waves, was transferred to the University of Maryland, where Erickson had become a professor. Although the original observatory has been abandoned, similar research continues at the much larger Long Wavelength Array in central New Mexico. Later life In early November 1959, President Dwight D. Eisenhower's Secretary of Defense Neil H. McElroy selected Critchfield to be head of the Defense Advanced Research Projects Agency. McElroy hoped that Critchfield would be able to fix the nation's trouble missile program, but Critchfield was reluctant to serve at the director's $19,000 salary. McElroy then offered to let Critchfield serve without pay, with the government paying only his expenses of $15 per day, while allowing Critchfield to continue to draw his Convair salary of around $40,000. Critchfield accepted this offer, but ran into a storm of political and media criticism over the conflict of interest involved in heading an agency that did $4 million worth of business with Convair each year. Critchfield then withdrew his name from consideration. In 1961, Critchfield accepted a professorship at the University of Wisconsin, but before he moved to Madison, his friends at Los Alamos, J. Carson Mark and Norris Bradbury offered him a position there that he took instead. He held this position until he retired in 1977, but he continued his association with the laboratory until his death after a long battle with cancer on February 12, 1994. His obituary in Physics Today was written by Carson Mark, Louis Rosen, Edward Teller, and Roger Meade. Charles Critchfield is buried next to his wife, Jean, in Guaje Pines Cemetery in Los Alamos County, New Mexico. Books Science textbooks Theory of Atomic Nucleus and Nuclear Energy Sources (1949) - co-authored with George Gamow References External links 1993 Audio Interview with Charles Critchfield by Richard Rhodes Voices of the Manhattan Project 1910 births 1994 deaths People from Shreve, Ohio Columbian College of Arts and Sciences alumni 20th-century American physicists Manhattan Project people Los Alamos National Laboratory personnel People from Los Alamos, New Mexico Fellows of the American Physical Society