Neither program managed to overcome the problems of shielding and weight. The development of intercontinental ballistic missiles in the 1950s, moreover, weakened the case for developing nuclear-powered bombers. The nuclear airplane became redundant from a military point of view, as ICBMs avoided the problems of manned nuclear flight. They had only one-way missions, needed no refueling, and did not have pilots to shield. Without a military justification for atomic flight, funding withered away.
The nuclear airplane began to die a slow death. In the late 1950s, the Eisenhower administration cut the program’s budget. Nikita Khrushchev slashed funding for the Soviet equivalent. By 1961, both countries had dismantled their projects for manned nuclear-powered airplanes. Atomic flight seemed doomed.
In a last-ditch effort to keep the nuclear airplane on the table, military strategists considered a radical solution: They could use pilots closer to death. The Air Force would use crews old enough to die of natural causes before the harmful effects of radiation could show up and thus, the logic went, sidestep the shielding problem. As the nuclear-policy expert Leonard Weiss explained in an article for the Bulletin of the Atomic Scientists, the proposal would have made radiation shielding unnecessary and decreased the weight of the plane significantly. It might have let the nuclear airplane take flight.
Read: The 60-year downfall of nuclear power in the U.S. has left a huge mess
The image of a corps of irradiated elderly pilots patrolling the world’s skies ready to unleash nuclear catastrophe drew on a form of ageism that pervaded Cold War apocalypse planning. In civil-defense plans for surviving a nuclear apocalypse, the old were always sacrificed first. Joe Martin at the University of Cambridge’s department of history and philosophy of science explained to me that Herman Kahn, one of the purported inspirations for Dr. Strangelove, made a ranking of food uses after nuclear catastrophe that reflected this Cold War age bias. The scale ranged from grade A (high-quality food reserved for pregnant women) to grade E (radioactive food only good for feeding animals). People over the age of 50 composed group D. Kahn put it bluntly in his book On Thermonuclear War: “Most of these people would die of other causes before they got cancer.”
Even that shocking proposal failed to save the nuclear airplane. The Eisenhower administration concluded that the program was unnecessary, dangerous, and too expensive. On March 28, 1961, the newly inaugurated President John F. Kennedy canceled the program. Proposals for nuclear-powered airplanes have popped up since then, but the fear of radiation and the lack of funding have kept all such ideas down.
The Air Force still maintains its affinity for older pilots. It has the highest enlistee age limit of any branch in the military, and it increased that limit to 39 years old in 2014. Some pilots could be much older. Last year, in response to a shortage of nearly 2,000 pilots, the Air Force beckoned back retired service members as part of the Voluntary Retired Return to Active Duty (VRRAD) program. VRRAD gives 1,000 former airmen and airwomen the option to return to active duty, possibly including combat duty. Referring to the placements of these retirees, an Air Force spokesperson said last year, “Everything is on the table.” Almost everything, at least: None of these pilots will ever fly a nuclear aircraft.