A Defense Department mock-up showing how the drone it hopes to design would navigate through indoor spaces. (Defense Advanced Research Projects Agency)

At some point in the near future, the first clue that an Osama bin Laden might have that he's been tracked down inside his Abbottabad compound might not be the sound of helicopters outside, but the buzzing of a bird-size drone in his bedroom doorway. The Defense Department's Defense Advanced Research Projects Agency (DARPA) is asking researchers to help develop drones capable of flying up to 45 mph indoors and small enough to slip into a building through an open window.

The inspiration for the program? The goshawk, a bird of prey with a remarkable ability to navigate through dense woodlands without, as DARPA program manager Mark Micire puts it, "smacking into a tree." The avian-influenced project is being called the Fast Lightweight Autonomy Program.

Or, yes, that's right, FLAP.

Drones, or unmanned aerial vehicles, are used extensively by the military outdoors, both to get an overhead read on urban environments or to survey unstable disaster zones. But seeing inside a building typically requires a soldier to enter a confined space where he or she could be vulnerable. Some structures are impossible to enter at all, whether that's because they're protected by enemy soldiers or because they are too damaged to walk around in safely. (The use of drones, of course, has raised questions about the ethics of killing someone remotely; it's unclear whether these indoor drones could ultimately be weaponized.)


A brown goshawk. ( Frankzed under a Creative Commons license.)

What DARPA wants researchers to develop are so-called autonomy algorithms that would make it possible for drones to quickly find their way around corners and through indoor obstacles without human intervention. The agency is also interested in drones with the ability to learn from their past travels. The new indoor devices, says DARPA, should have the capacity to answer intuitively, "Have I been here before?"

Small indoor drones already exist, but they're dependent on both human operators and GPS-based navigation. These new flyers would be operated by a remote pilot who could be sitting miles away, but the drone still must be able to make minuscule, split-second decisions to navigate a room on its own.  Moving more than 60 feet per second, they should be fast enough to stay one step ahead of soldiers or those they are pursuing, according to DARPA.

DARPA plans to award several grants and contracts worth up to $5.5 million each to get FLAP off the ground. The agency declined to comment on details of the program beyond those contained in an announcement of the project.

Technology developed by the military, of course, often gets transferred into civilian life. But in the United States, the Federal Aviation Administration has long delayed issuing rules that would allow drones to be used widely for commercial purposes. Those rules are expected to finally come next year, but in the meantime the FAA has made exceptions for filmmakers who use camera-equipped drones to create impressive outdoor video takes. Imagine what they'll be able to do once those cameras are capable of following the shot indoors, too.

Correction: An earlier version of this story contained a reference to pilots "sitting millions of miles away" from the drones they are operating. That detail has been changed to reflect the fact that such a thing is, of course, impossible.