January 12, 1942: Just one month prior, the attack on Pearl Harbor had flung the U.S. into a war in the Pacific, and American bats weren’t pulling their weight in the war effort. Luckily, a lone dentist in Pennsylvania had a plan that could both beat Japan and get our furry little friends fighting: strap tiny, tiny bombs to them, and let them burn the island nation down.
Dr. Lytle S. Adams wrote a letter to the President detailing his proposal: Americans attach incendiary time bombs to bats and release them at night over Japanese industrial centers, where they land at dawn. Then, timer goes off, the sleeping bats burst into flame, and anything nearby is reduced to charcoal. Surprisingly, President Roosevelt OK’d the plan and Army brass gave it a new name, Project X-Ray. Special bombs were designed to hold sleeping bats, which were then dropped out of a plane, and special bombs were designed as incendiary bat backpacks. Too bad the bats themselves kept either dying too early, inside the plane, or dying too late, when they didn’t wake up before hitting the ground. Two years and 2 million dollars later, the project was scrapped.
In spite of the WWII SNAFUs, bats still have a place in today’s military. Well, robot bats do, anyway. Micro Air Vehicles (MAVs), the little cousins of the Unmanned Air Vehicles (UAVs) recently put to shady use in Pakistan, are just what they sound like—small robotic things that fly. Some are like little UAVs, simply robot planes or robot helicopters, but some MAVs, the ornithopters (a combination of the Greek for “bird” and “wing”), flap.
Here’s where the bats come back—one lab in Brown’s BioMed center is doing the research that might some day lead to MAVs that fly like bats. As Joe Bahlman, a PhD student in the lab working on a flapping bat robot, noted, “if it’s flapping, people think it’s a real animal, so you can hide in plain sight,” making them ideal for reconnaissance. But not just any flapping will do; hummingbird excepted, birds are designed to fly forward, fast, which is good for getting somewhere but lousy for sticking around if you don’t have any legs. Bats, on the other hand, can hover, fly backwards, and turn on a dime, perfect for staying mobile but stealthy.
Dan Riskin, a post-doctoral student in the lab, explained the basic research process: inject live bats with saline solution to simulate a payload, “which they pee out very fast, but they’re kinda bloated for a while,” put them in a wind tunnel, and take super-high-speed (1000 FPS) video for later analysis.
Thanks to the unique way bat wings work, their flight merits special study. Riskin described how bats differ from bugs and birds in terms of control: bug wings are like rigid paddles, thwacking the air; birds can slightly change the pitch and angle of their feathers, but each feather is still inert, like the rigid insect wings. Bats, in contrast, have 17 joints per wing and muscles within the wing membrane itself, disconnected from any bones. This means that they can make minute adjustments in wing tension and shape at will, but also makes studying their flight especially tricky.
Since bat flight is made up of so many motion parameters, tracking the effect of one flexed muscle is nearly impossible. To simplify the observation, Bahlman hopes to isolate individual variables with his robot model. So far, it’s made of materials imitating the organic, has two degrees of shoulder motion, and can flex its major joints, but future versions might have an active membrane, à la Batman’s cape in the recent movies, based on work coming from collaborators at the University of Michigan.
While the Air Force provides some of the bat lab’s funding, no future plans to integrate time bombs, X-Rays, or oral surgery were mentioned.
June 22, 1941. A peace had held on the Eastern Front since the outbreak of war two years prior, but with Western Europe in its hands, Hitler’s Third Reich turned on its Soviet neighbors. Stalin had prepared for this, but thought that Germany would wait until ’42 before breaking the non-aggression pact. The Soviet army was desperate to stop the Blitzkreig’s eastern advance.
So, in a move prefiguring future Allied enlistment policies (cf. Project X-Ray), the Russians strapped bombs on dogs and trained them to run at tanks. The concept started out more humanely, as trainers tried to teach the dogs to run to a tank, pull a quick-release tab with their teeth to plant a time-bomb, then run back to safety, but the dogs, being dogs, couldn’t quite pull off the procedure.
Following the Soviet tradition of brutally simple technology (cf. AK-47s, Molotov cocktails), they then decided to simply tie some mines to the dogs’ backs and rig the triggers up to a big stick. Ideally, the dogs would run under tanks, the stick would get pushed down, and everything would explode, destroying tank and dog.
While the plan seemed airtight—foolproof, even—it ran into some snags on the battlefield. The dogs were scared by the moving, shooting German armor, and often ran for alternative cover, including friendly tanks, leading to alternative explosions.
In spite of the program’s flaws, the dogs did manage to down a few enemy tanks (if not the 300 claimed by Soviet propaganda), but when German soldiers were ordered to shoot any dogs on sight, effectiveness dropped. By 1942, the kamikaze canines were mostly discontinued.
Long before the ill-conceived Soviet program, though, dogs have fought our wars. Going back as far as Ancient inter-city-state strife, man’s best friend has fought next to human soldiers in close combat. In recent centuries, however, the advent of firearms has demoted them to scouts, messengers, or pack animals, and even those auxiliary roles are dwindling in modern warfare.
Despite the downward trend, there’s at least one dog that has a definite future in 21st-century combat, and its name is BigDog. With progress comes sacrifice, though, and even biology has its limits. BigDog, unlike his poochy predecessors, doesn’t have a tail to wag, a mouth to bite, or even much of an appetite. Which makes sense, since BigDog is a robot.
Developed by Boston Dynamics, a robotics company based in Waltham, MA, BigDog is probably best known through the YouTube videos of its eerily lifelike legs, organically striding beneath a featureless metal body. Anyone watching usually starts shuddering when the waist-high BigDog, walking through an icy New England parking lot, gets kicked from off-screen. It reacts, which is startling enough to see in a machine, but then proceeds to scrabble on the ice like a hideous, all-black, headless fawn getting its first legs.
But the creators of BigDog built the thing for more practical applications than online creep-out celebrity. The Boston Dynamics website calls BigDog “The most advanced rough-terrain robot on earth,” with the ultimate goal of being able to “go anywhere people and animals can go.” A part of realizing that goal is letting the robots think for themselves, to a certain degree, and BigDog enjoys semi-autonomy. The company has designed optics systems to let it follow a human automatically, useful in its most immediate role as a robot military pack-mule. If there aren’t enough soldiers to carry the equipment, there probably aren’t enough to fiddle with remote controls, either.
Following, carrying stuff, going “anywhere[...]animals can go”—all seem like jobs well-suited for the animals BigDog might replace, bringing the necessity of designing a robot for the job into question. Marc Raibert, the leader of the BigDog and LS3 (the prototype BigDog 2.0) efforts at Boston Dynamics, noted the hassles that come with biology. Animals need to eat, even when not on duty, and refuse to continue working when scared or overtired. “Pack animals can only go on missions where a human is leading,” Raibert added, “we believe that future robots will be able to take the lead.”
“BigDog Weaponized” is the title of a recent YouTube video posted by Boston Dynamics employees, but it’s a bullfighting spoof, with horns tacked on BigDogs non-head and engineers waving red capes around. Raibert said that the company has “no plans to weaponize any robots” for real, and pointed out some more peaceful applications for a potentially scary machine. Anywhere that legs are better than wheels, BigDog can help. Raibert mentioned rescue from rubble after disasters, mountainside farming, and even personal transport, saying, “imagine a day when roads become obsolete, with us all driving legged vehicles from home to work through pristine forests.”