Militaries around the world work extremely hard to keep their latest innovations secret, for obvious reasons. But this secrecy can spark intense curiosity and speculation among members of the public.
Every so often, military secrets are released, if only many decades after they were invented. One such example is Fogbank – a secret material used in the production of nuclear warheads. Its manufacture was so highly classified that details of the process were lost.
So, when a fresh batch of the material was needed to refurbish old warheads, the US National Nuclear Security Administration was forced to spend a lot of time and money to rediscover the process. Although its existence is now public knowledge, the exact nature of Fogbank still remains classified.
Arms experts believe it’s an aerogel material, designed to become superheated plasma when the weapon’s fission stage is detonated, which then triggers the final, fusion-stage detonation of the weapon.
Fogbank was first manufactured in Tennessee between 1975 and 1989. After the final batch of warheads was produced, the facility was deactivated. Around 20 years later, when the US military decided to refurbish its old nuclear warheads to extend their service life, those involved in the project realised that very few records about the manufacturing process had been retained.
Worse still, most of the staff that had the expertise to manufacture the material had either retired or left the agency. After a costly reverse engineering process, it was finally manufactured again in 2008.
It’s unclear whether Fogbank is still being used in new nuclear warheads today. The public got another sneak peek into US military secrets this year, when the Pentagon produced a report examining UFO sightings dating back to 1945.
The report concluded that the majority of UFO sightings could be traced back to ordinary objects from Earth – in many cases these objects were actually classified military technology.
For example, the high number of reported UFO sightings in the 1950s and 60s was caused by tests of advanced US spy planes and space technology, such as high-altitude balloons and fighter planes. Several secret research projects involved aircraft that were saucer-shaped, such as the Canadian VZ-9AV Avrocar fighterbomber, which was designed for vertical take-off and landing.
The Pentagon report examined archives and classified documents from all official government investigations into ‘Unidentified Anomalous Phenomena’ and found no evidence for extraterrestrial technologies on Earth.
The US Department of Defense is currently considering reducing the classification level for information about some of its secret space programmes, in the hope that information about its defence capabilities will act as a deterrent to its adversaries.
In an unusual move, the US Space Force released some details about the capabilities of the Silent Barker satellite, which monitors satellites and spacecraft orbiting Earth, ahead of its launch in September 2023. Perhaps, if Pentagon officials pushing for more transparency about their military space technology get their way, disclosures like this could become more common in the future.
This article is an answer to the question (asked by Adam Costello via email 'What's the most secret weapon we know about?'
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