A robotic fly with a body not much taller than a penny standing on edge has taken to the air, passing its tests with flying colors. The RoboBee, as it's called, is the smallest artificial insect yet flown, according to the team that built it. It lifts off the table, hovers, and flies in different directions. At this point in its evolution, the bug is still tethered by thin wires that allow its designers to power and guide it. And landing remains an issue. The robot ends its sorties with all the grace of a mosquito nailed with a burst of Raid.

Still, the tiny craft's success the team that designed it said it was the first such object to fly in a controlled manner represents a key step in developing insect-size drones that designers say could one day search collapsed buildings for survivors after a disaster, sample an environment for hazardous chemicals before humans are sent in, or pinpoint enemy soldiers or terrorists holed up in urban areas.

Some members of the team suggest that future generations of the bug could serve as a robotic pollinator for plants, though without the side benefit of honey.

Together with an announcement this week that another team of researchers has developed a buglike compound lens for collecting video taken with small aerial vehicles, the description of RoboBee appearing in Friday's issue of the journal Science signals how far robotic bug research has come in the past decade.

The team's next challenge is to gradually move the bug from tethered to increasingly autonomous. At some point, that means it needs to see where it's going. In an e-mail, Rogers says the team hopes to improve the compound lens's resolution its ability to distinguish between two closely spaced objects. Indeed, he says he's confident that the approach will yield lenses that outperform even the best insect eyes.

"We are working on that, and on schemes that allow the overall size of the camera to be reduced,"
he says, including a size befitting a RoboBee.