If you've ever had a portable computer shut down because the battery went dead, you should know the Air Force shares your problem. And it's trying to solve it, too.

The Air Force last week awarded General Dynamics Corp. a $1.3 million contract to develop 10 prototype tablet computers -- powered by long-lasting liquid fuel cells -- to replace some of the computers used by the service's air traffic controllers. The goal of the project is to reduce reliance on spare batteries and centrally located recharging equipment, thereby enhancing the Air Force's ability to conduct field operations.

"These are for scouts who determine the geography fit for landing tactical aircraft," said Chris Marzilli, senior vice president and deputy general manager for General Dynamics C4 Systems, a unit of the Falls Church company.

Work will be performed in Scottsdale, Ariz., and the tablets will be tested and evaluated by the Air Force Research Lab at Wright-Patterson Air Force Base in Ohio. The project is part of a larger effort led by SRA International Inc. of Fairfax to develop new information technologies for the military.

The prototype tablets will combine commercial, off-the-shelf computer equipment from Itronix Corp. of Spokane, Wash., and privately developed fuel-cell technology from Medis Technologies Ltd. of New York into "an overall lighter, wearable and more deployable package," Marzilli said.

Medis's liquid fuel-cell technology has worked with small electronics, such as cell phones and digital cameras. By the end of 2004, Medis expects to start distributing a small, disposable power pack that lets users operate their electronic devices while they recharge the primary battery.

General Dynamics began working with Medis in May 2003 to adapt its fuel cells to portable computers for the Defense Department. The company is hoping to achieve 12 hours of continuous operation.

"Computer technology will always advance; the power systems traditionally have not advanced. Finally, there's breakthrough technology," Marzilli said.

The Air Force prototype could have implications for other Defense Department applications that rely on batteries, such as the Joint Tactical Radio System of handheld devices, Marzilli said.

JTRS (pronounced "jitters") is a multibillion-dollar program to build radios that can talk with each other regardless of the communications system they use. General Dynamics is one of several contractors building JTRS radios.

In addition to integrating liquid fuel-cell technology, General Dynamics will experiment with other ways to modify the Itronix tablet PCs for the Air Force.

The company is looking to make the tablets compatible with night-vision goggles, easier to read during daylight hours and bootable in a stealth mode so they can't be detected by hostile forces.

Brad Grimes and Patience Wait are staff writers with Washington Technology. For more details on this and other technology contracts, go to www.washingtontechnology.com.

General Dynamics will develop prototype tablet computers powered by fuel-cell technology for the Air Force's air traffic controllers.