The U.S. Air Force Is Tearing Down a Giant Spy Antenna
’Elephant cages’ are a dying breed
The U.S. Air Force has started tearing down a massive antenna in Japan. Once used to scan airwaves around the world, these systems have become obsolete as countries change how they communicate.
On Oct. 15, workers began removing the antenna—designated AN/FLR-9—at Misawa air base in Japan. The demolition has been on the flying branch’s agenda for more than a year now.
“Technology and fiscal constraints have driven Misawa Security Operations Center to seek new ways of doing business,” Col. Joseph Winters told Air Force reporters. The antenna—which is almost 1,500 feet wide—should be completely gone by the end of 2015.
Misawa’s system was one of eight AN/FLR-9s the Pentagon built in the United States, Europe and the Pacific during the 1960s. The site actually has three concentric rings of smaller antennae, hence the popular “elephant cage” nickname.
Chief Master Sgt. Joseph Rabig came up with the moniker for security purposes, says D.D. Kavanagh, a retired member of the flying branch’s Pacific Electronic Security Division, according to the Federation of American Scientists’ Website.
“Joe came up with the explanation that it was an ‘elephant cage.’ He maintained that was their purpose and justified the explanation by pointing out [that] ‘they work pretty well, don’t they? You don’t see any elephants running around loose, do you?’”
The Air Force, Army and Navy, in cooperation with the National Security Agency, operated the elephant cages. The giant antennas could scoop up high-frequency radio transmissions from thousands of miles away.
The setup exploits the basic physics of high-frequency communications to pull off this feat. To reach long distances, radio waves bounce off of the ionosphere in the upper atmosphere.
America’s huge antennas would intercept those transmissions as they fell back to Earth. With the AN/FLR-9 at Misawa, the NSA could keep tabs on Soviet, Chinese and North Korean movements in the Pacific and listen in on their conversations.
But after almost 50 years, the elephant cages simply can’t keep up anymore. And the NSA and the military might not be particularly sad to see them them go in the end.
For one, this method of grabbing intelligence has always been fickle. A signal could easily weaken after ricocheting off hills or mountains or due to changes in temperature or even just heavy cloud cover.
The Pentagon has likely been able to substitute the Air Force’s RC-135 and U-2 spy planes, as well as satellites, for the grounded antennas, Tim Brown told War Is Boring.
With the U-2 possibly retiring soon, the Pentagon is also interested in sending drones to scan for enemy transmissions. The Air Force and Army both want signals intelligence packages for unmanned aircraft such as the Global Hawk and Gray Eagle.
But even more importantly, China and North Korea have seen “a general trend” away from high-frequency transmissions, Dr. Jeffery T. Richelson, a senior fellow at the National Security Archive, tells War Is Boring.
Brown agrees with this assessment. “The [elephant cages] are obsolete, mainly because the Cold War is over, and the enemy doesn’t really use long range HF [communications] anymore.”
Richelson and Brown both suggest that Beijing and Pyongyang have no doubt moved on to buried cables or to higher frequencies than the AN/FLR-9s can handle. Fiber optic lines, for instance, are a great replacement “A, because the bandwidth is huge and B, it’s less susceptible to intercept,” Brown notes.
As a result, “it is not clear there is anything required to replace the FLR-9 HF capability,” Richelson adds. “Operational security as well denial and deception—e.g., underground facilities—can limit what those systems detect.”
And this goes for America’s other aerial spies, as well. Intelligence agencies are probably relying heavily on traditional tradecraft to get at communication lines tucked away from prying eyes.
“The CIA-NSA joint venture, the ‘Special Collection Service’ goes out and physically taps the fiber optic cables, bribes and blackmails embassy code room workers, etc.,” according to Brown. “It’s always easier to steal codes than to break them.”
Really, the removal of the last elephant cages is “a reflection of the changes in communications methods that have occurred over the last several decades,” Richelson says. After the antenna in Japan goes, the Pentagon will only have one AN/FLR-9 left at Joint Base Elmendorf-Richardson in Alaska.
“The elephant cages, like elephants, are rapidly going extinct,” Brown says.