Witness from the Sky
How the Lab photographed fireballs from above
October 10, 2023
The cameras needed to be secured and a network of timing systems set as the first test, codenamed “X-ray,” rapidly approached. Instead of guns on these military aircraft, the “planes appeared to have a hundred eyes,” intoned the narrator of an Operation Sandstone documentary. This scene, which first played out during the 1946 Operation Crossroads Baker test, would repeat itself across decades of nuclear tests. Through their unique relationship with the explosion, the aerial surveyors were able to capture stunning photographs as planes flew around and above while shutters rapidly clicked.
While aerial images of fireballs and mushroom clouds from the weapons testing era are breathtaking, they also provide measurable—and irreplaceable—visual data that are as critical to research now as during the decades of nuclear testing.
“In the absence of weapons testing, these photos are absolutely vital today,” said Nanette Mayfield, Digital Collections group leader, National Security Research Center (NSRC). “Researchers rely on them for their national security work. Understanding past weapons tests helps scientists working on our nation’s stockpile, among other aspects of the Lab’s national security mission.”
As such, the NSRC is digitizing aerial test shot photographs by request and for publication projects. According to Tim Goorley, deputy director of the Strategic Analyses and Assessments Office, these photos are “evidence of the physical phenomena that occur during a nuclear detonation—proof of what really happens.”
As one example, Goorley said, images of the Nagasaki explosion provide visual information as to the different components of a mushroom cloud: the pure white “detonation debris cloud . . . of condensed water” and the “dirty cloud” made up of dirt and debris from the ground. The mixing of the two clouds, or lack of mixing, indicates the possible extent of fallout, or radioactive particles in the air after a detonation. Meanwhile, an aerial photo from the Operation Crossroads Able test “shows [that] the shock speed in the water is faster than the shock speed in air.”
From blast to cloud
During atmospheric nuclear testing operations, photo planes carried a breadth of aerial mapping and military-type reconnaissance cameras. The KC-1, K-17, K-24, and high-speed 16-mm Fastax, which shot 3,000 frames per second, all simultaneously captured the evolution of a blast from detonation to the tops of the clouds. Their purpose was to measure yield, altitude, and diameter.
The bird’s-eye view provided by aerial photography became essential as testing moved to higher altitudes and camera technology improved. In nuclear testing, weather was a variable factor, especially over the Pacific Ocean, where a large volume of testing took place, and unexpected heavy clouds often obscured ground views of atmospheric tests. A 1962 preliminary report from U.S. defense contractor Edgerton, Germeshausen, and Grier (EG&G) confirms the limitations of terrestrial cameras while affirming that photographs taken from a C-130 aircraft provided “excellent images of [mushroom] clouds.” EG&G was the Lab’s technical consulting firm, whose innovations in high-speed photography and timing systems made more advanced visual data collection possible.
Human element
Taking photographs from a plane had its challenges. According to Peter Kuran, nuclear testing documentary filmmaker and author of How to Photograph an Atomic Bomb, photographers and aircrew worked in open, depressurized planes at high, frigid altitudes. The extreme conditions didn’t rattle the aircrew as much as the blast shockwaves did, according to Kuran. Planes flew as close as 6 miles from the detonation at an altitude of 11,000 feet, and despite their colleagues’ forewarnings, the shockwaves that slammed into their planes unnerved the crews. “The first time was the one that forever stayed in their memories,” Kuran said.