Small unmanned plane provides cheaper method of surveillance.

There aren't too many military planes that can be held in the palm of a hand. But an unmanned surveillance vehicle no larger than a child's model plane is on its way to support U.S. military efforts in Afghanistan.

Two prototype Sentry Owl systems, made by Lockheed Martin Corp. at its Palmdale Skunk Works facility, have been delivered to the Air Force.

The systems--with a total cost of $3 million--each consist of six planes, a ground control station and remote-viewing terminal. They are designed to monitor U.S. base camp perimeters as well as battlefields for enemy vehicles and personnel.

The "micro air vehicle" is equipped with a sensor package that will provide military officials with real-time high-resolution imagery day or night.

"What is unique about this system is that it allows Air Force cops to have another sensor to see beyond the base perimeter where they would (otherwise) have to send out a squad of personnel," said Major Mike Giger, acting director of the Air Force's Force Protection Airborne Surveillance System, which oversees the program. "You don't have to put a man in harm's way.'

The device weighs from two to six pounds, has wing spans of two to five feet and flies at altitudes of 200 to 500 feet at speeds of 39 to 53 miles per hour for up to one hour before batteries need to be recharged.

The systems were produced under a one-year contract awarded last March by the Defense Advance Research Projects Agency, the Pentagon's research and development arm. Lockheed is expected to deliver six remaining systems by the end of the year, military officials said.

Under development since 1998, the Air Force put the Sentry Owl into limited production after testing this summer showed the vehicle to be a lower-cost alternative to the more expensive unmanned surveillance vehicles currently popular with the military. Those include Northrop Grumman Corp.'s Global Hawk, which came under fire this summer by Pentagon officials when they learned the cost per plane would eventually rise to $75 million, up from the originally projected $16 million to $20 million.

"I don't think anybody would be talking about this in place of the Global Hawk," said Phil Coyle, a senior analyst with the Center for Defense Information, a Washington research and policy group. "But it's a complement to Global Hawk at a time when the military is facing many new costs just because of the war in Afghanistan."

The Global Hawk has far superior capabilities, allowing it to fly 65,000 feet high for 31 hours at 377 mph carrying a 2,000-pound payload consisting of sensors and radars.

Besides being cheaper, the Sentry Owl's high-resolution imagery transmits to ground control using a camera weighing less than four-ounces with a sensor eye the size of a viewfinder on a 35-millimeter single-lens reflex camera. And there are few defense secrets to lose if something goes wrong.

"(The body) is made with a sophisticated foam material. Most of the materials in the camera are off the shelf. So they crash and burn, who cares?" said Dianne Knippel, communications manager at Skunk Works.

Operating the Sentry Owl requires a two-person crew. One controls the plane's flight using an on-board Global Position Satellite system or monitoring a pre-programmed pattern, while the other views data transmitted through an antenna on the viewing terminal, which displays a map of the designated area.

The current contract contains an option for an undisclosed number of additional systems.