In late December 2003, the CIA revealed many never-before-seen tools of the spy trade at its own museum near Washington. These included a listening device designed to seem like tiger excrement that recorded troop movements in Vietnam, and a robot fish that collected water samples near hidden nuclear plants. Then, there was a tiny dragonfly.
At first glance, this Seventies Cold War artifact looked like several Common Green Darner (Anax junius) or perhaps a Blue-faced specimen (Coryphaeschna adnexa) for those who’re squinting—its face, forewings, and thorax were all in the correct place. But look closer, and also you see that this small bug isn’t really a bug in any respect. It’s an “insectothopter,” a bug-sized spy that represents our first big step into the complex world of insect robotics. It was an incredible achievement at a time when the microprocessor was a novel invention.
Now, some 16 years after this public debut—and nearly 50 years since its first flight—newly released documents show every small detail about how the CIA created such a powerful micro-robot.
Putting the Bug In “Bugging”
Despite being a star attraction on the CIA’s museum, many details concerning the bug remained a secret for many years until John Greenwald, founding father of the anti-secrecy website The Black Vault, put in a request for documents under the Freedom of Information Act (FOIA) in the summertime of 2013.
“I’ve learned over time, the U.S. military and government often will acknowledge something or confirm something exists, and over and over that largely satisfies the general public’s curiosity,” Greenwald told Popular Mechanics. “Nevertheless…we frequently do not get the total story. So I am going after documents never-before-released to inform either more of the story, or the actual story.”
Seven years later in January 2020, Greenwald received a stack of documents detailing the dragonfly’s design and construction—and the story stretches back into spying’s peak in the course of the Cold War.
Back then, bugging—or listening in on conversations with electronic devices—was a strong and comparatively recent espionage tool, but some places remained harder to achieve than others.
So the agency turned to retroreflectors, tiny glass beads that reflect laser light (on this case, a laser beam) back at its source. This reflected laser beam will be affected by any vibration within the glass, which alters the gap that the beam travels. The CIA can then analyze the returned beam and recreate the vibrations that disturbed it, essentially extracting sound from light. In practice, these retroreflectors acted as a distant microphone to snoop on any conversation. In 1970 the CIA already used an analogous technology to select up vibrations from window glass.
The real challenge was getting the small retroreflectors onto a window sill, over an embassy wall, or next to the correct park bench at just the correct moment while also remaining inconspicuous. The CIA had previously tried fitting a cat with a microphone, however the project resulted in disaster. The agency needed one other approach.
That’s when Don Resier, deputy head of the CIA’s Office of Research and Development, got here up with an alternate. As a substitute of attaching microphones on common mammals, a robot insect could pass unnoticed. Dubbed the “insectothopter,” he assigned Charles Adkins to steer the project.
Adkins’ goal was to construct a tool that would fly 200 meters and deliver 0.2 grams of retroreflector beads without being noticed. Resier thought a bee can be a great candidate, however the insect’s complex flight mechanics wouldn’t be fully understood until many years later in 1999.
What Adkins really needed was stability because computers of the day were far too big and slow to handle complex controls. Luckily, certainly one of Adkins’s fellow CIA scientists was a dragonfly enthusiast and had a preserved collection.
In accordance with Adkins, this scientist, whose name remained redacted within the FOIA documents, said that a dragonfly’s aerodynamics were way more stable. Along with being incredibly maneuverable, dragonflies are exceptionally good gliders in comparison with other insects, which helps them conserve energy on long flights. The scientist brought in some specimens, and when Adkins pressed him on the problem, “the old fellow plucked the insect from its perch and tossed it into the air,” Adkins wrote. “It made about two circuits and landed nicely on the desk.”
The demonstration convinced Adkins, however the team still needed to work out replicate a dragonfly’s wings, which flap 1,800 times per minute. To tug this off, scientists used a tiny fluidic oscillator, a tool with no moving parts that’s completely driven by gas produced by lithium nitrate crystals. When initial tests showed that the prototype couldn’t carry the required 0.2 gm payload, designers added additional thrust by venting exhaust backward, very like jet propulsion.
After a fast dragonfly-inspired paint job, the drone was ready for (covert) motion, weighing slightly below a gram. Its glittering ‘eyes’ were the glass retroreflector beads destined to eavesdrop on unsuspecting targets.
The Crosswinds of Reality
While the CIA now had its robo-bug, it still needed a technique to control it.
Radio control was out of the query because any extra weight would doom the small insectothopter. So CIA scientists turned to the identical lasers used for the retroreflectors. This was a conveyable laser unit, often called ROME, that produced an invisible infrared beam. The concept was that the laser would heat a bimetallic strip that will then open or close the dragonfly’s exhaust. While effectively throttling the ‘engine,’ one other laser—acting like a form of rudder—would then steer the drone to its desired destination.
With its gas-pumping engine and laser-based navigation system, the insectothopter could fly for under 60 seconds. But this was good enough to get the dragonfly—and its payload—to a goal some 200 meters away. Seeing as there was no landing gear, the dragonfly was likely a crash and perch operation.
“The feasibility of a controlled insectothopter vehicle with limited operational capability has been investigated and all program goals so far have been achieved,” Adkins said in his final 1974 report.
The primary flight of the insectothopter, in accordance with the CIA.
While the dragonfly proved to be an incredible feat of engineering—and worked perfectly under testing conditions—a laboratory rarely resembles reality. The most important problem with the insectothopter’s design was that an operator had to maintain a laser manually trained on the drone during flight. Easily done in a static wind tunnel, less so in blustery and unpredictable conditions.
“Flying in a straight line in still air just isn’t that difficult. It’s a bit like a paper airplane, especially for those who give it a lift with some compressed gas,” Simon Walker, an authority in biomechanics on the University of Leeds within the U.K., told Popular Mechanics. “In case you examine the veins in a dragonfly’s wing, it forms a part of an incredibly complex, deformable structure that bends particularly ways under stress, and that deformability is absolutely necessary to the aerodynamics.”
In theory, the insectothopter could still be flown in lower than 7 mph winds, but “the final word demonstration of controlled powered flight has not yet been achieved,” Adkins ultimately reported. “Though the flight tests were impressive, control in any form of crosswind was too difficult.”
This system cost $140,000, about $2 million today, which is pocket change once you consider the billions spent on modern spy satellites. But no CIA missions ever required the agency’s recent dragonfly spy, and the project shut down.
Dragonfly Descendants
The Delfly micro-drone captured with a slow-motion camera at 6,000 frames per second.
Prior to now 50 years, our understanding of insect flight—and the electronics needed to duplicate it—have advanced tremendously, even when nature still has a forefront.
“We still can’t construct something as effective as a bumblebee wing which still works well even when it is broken,” Walker says, but he points to the Skeeter drone, developed by Animal Dynamics, as a great example of how our greater understanding of biomechanics can create a real heir to the insectothopter.
An agile micro-drone, Skeeter can also be inspired by dragonflies with its 4 flapping wings. While the insectothopter couldn’t handle a gentle breeze, the Skeeter can manage “high gust wind conditions with greater tolerance and endurance than existing quadcopter equivalents,” in accordance with the corporate.
Researchers on the University of Delft have also been working on quite a lot of robot dragonflies since 2005. Their smallest, the Delfly Micro, weighs just three grams and has a four-inch wingspan. This robo-bug can fly for 3 minutes on battery power and is much more agile than its ancestor. It might also relay images from a video camera, something the CIA’s designers could only dream of.
Other projects are even more exotic than the CIA’s original ideas. In 2017 researchers at Charles Stark Draper Laboratory created a cyborg dragonfly. Scientists modified a living dragonfly so it may very well be steered by handheld remote control using “steering neurons” implanted in its eyes.
While all these concepts far surpass the CIA’s initial efforts, additionally they receive the all-important good thing about a half-century of technological evolution.
“We hear about drones today again and again,” says Greenwald. “This was an unmanned drone from the Seventies, the scale of a bug. The Seventies! Just think what form of advancements they’ll make in 50 years.”
While the unique insectothopter never succeeded, Adkins and his team stumbled upon a stable platform for future insect robotics. What would an analogous CIA drone seem like in 2020? Who knows—that continues to be classified.