Photo: Operation Hardtack, 1957. Courtesy of LLNL

At the climax of the Cold War race for nuclear superiority, the United States of America detonated 210 atmospheric blasts around the world. Scientists captured the explosions on film, to document the damage done and the immediate fallout. Some 10,000 of those films were made and stored away, most never to be opened again.

Now a project at the Lawrence Livermore National Laboratory is racing against time to preserve the decaying films—and they’re finding that the data that was reached from the manual assessment of the footage decades ago was wildly inaccurate.

The reevaluation could change the way that nuclear weapons are understood, according to the experts.

“Most the data that’s published was wrong,” said Greg Spriggs, a nuclear weapons physicist at the national lab.

The multiple camera angles show mostly blurry glows, but have provided vital scientific data to weapons experts—and policymakers—for a half-century.

The films, soundless, sometimes show a surreal extent of damage. Oftentimes the mushroom clouds bloom into darkness, following the flash.

The films document a period of breakneck experimentation, from the earliest atomic bombs, to the later thermonuclear weapons that threatened the existence of the world during standoffs between the Soviet Union and the U.S., most dramatically in the Cuban Missile Crisis of October 1962.

The Lawrence Livermore National Laboratory team has uploaded the digitally-preserved footage to Youtube. Included among the dozens of short clips are scenes from some of the most important experiments in the history of nuclear weaponry:

  • Operation Upshot-Knothole was a series of detonations in Nevada in 1953 to refine the hydrogen bomb, which had been tested for the first time the year before.
  • Operation Castle included six massive, and infamous, tests of high-yield hydrogen bombs in 1954 on Bikini Atoll.
  • Operation Hardtack was a series of 35 blasts in 1958 at the U.S. Pacific Proving Grounds.
  • Operation Plumbbob’s 29 tests are captured at different angles from cameras that were stationed in the deserts of Nevada in 1957.
  • Operation Dominic was the major aerial drop of hydrogen bombs from B-52s on Christmas Island in the South Pacific (now known as Kiritiamati). The 31 tests were made in the lead up to, and immediate aftermath of, the Cuban Missile Crisis—from April to November 1962.

The films were naturally breaking down. Griggs and others brought in film expert Jim Moye, who has previously workied on preserving films as important as the JFK assassination video, to work on the project.

“You smell vinegar when you open the cans, which is one of the byproducts of the decomposition process of these films,” said Spriggs. “They’re made out of organic material, and organic material decomposes.”

The films capture each event at approximately 2,400 frames per second. But the analog cameras, and the manual analysis accomplished in the 1950s and 1960s, resulted in the data being as much as 30 percent off, said Griggs. As many as 1,000 experts at the time were employed to enlarge single frames, and “eyeball” the estimates of the fireball and shockwave, millisecond by millisecond.

“We just decided to try to re-analyze the films and come up with better data,” Spriggs said. “We’ve also discovered new things about these detonations that have never been seen before. New correlations are now being used by the nuclear forensics community, for example.”

Contemporary innovation allowed the breakthrough. To analyze a two-second video would take eight hours of meticulous scrutiny. But Spriggs and two software developers at LLNL developed custom tools with MatLab and Python to automate some of the time-consuming operations—reducing that time to minutes.

Some 6,500 of the 10,000 films have been located. Some 4,200 overall have been scanned, and as many as 500 have been fully analyzed. The remainder of the project will take two years.

But the time spent will actually correct thinking on nuclear weapons—a threat that has been drawing headlines recently, considering their proliferation to North Korea and elsewhere.

“We need to be able to validate our codes and trust that the answers that are being calculated are correct,” said Spriggs. “The legacy that I’d like to leave behind is a set of benchmark data that can be used by future weapon physicists to make sure that our codes are correct so that the U.S. remains prepared.”