Why put up costly cell phone towers in thinly populated areas, when a few balloons would do?

In North Dakota, former Gov. Ed Schafer is backing a plan to loft wireless network repeaters on balloons high above the state to fill gaps in cellular coverage.

"I know it sounds crazy," said Schafer, who now heads Extend America Inc., a wireless telecommunications company. "But it works in the lab."

Extend America and Chandler, Ariz.-based Space Data Corp. are developing the technology, which is believed to be the first to use disposable balloons to provide cellular coverage.

A trial balloon will be launched in the next few weeks to test the idea, said Schafer, who left office in 2000 after eight years as governor.

"To cover every square mile of North Dakota, it would take 1,100 cell towers," Schafer said. "We can do the whole state with three balloons."

If successful, the hydrogen-filled balloons could be drifting across the stratosphere above North Dakota this summer, providing cellular coverage at a tiny fraction of the cost of building cellular towers.

Jerry Knoblach, the CEO of Space Data, says that although the balloon technology, called SkySite, is new to the cellular industry, "the platform is very well proven" for other purposes.

His company has launched thousands of the free-floating balloons in Texas, Oklahoma, Louisiana, Arkansas and New Mexico over the past year.

The wireless data network they encompass tracks oil company vehicles and monitors the production of oil wells and pipelines, he said.

Knoblach is certain the balloons will work for cellular service in North Dakota — even in cold or stormy weather. He said balloons were launched even during Hurricane Katrina.

Up to 20 miles above the earth, well above commercial airliner pathways, steady stratospheric winds would push the latex balloons across the state at about 30 mph. Each balloon would deliver voice and data service to an area hundreds of miles in diameter.

"Nine balloons would always be in the air, with some going up, some going down, and some in the middle," Schafer said.

The balloons swell from six feet in diameter to 30 feet after they gain altitude. Once a balloon leaves the state, its toaster-size communications pod would jettison, deploy a parachute and fall to earth, where it would signal its position.

"We'd pay some guy a bounty, put in a new battery pack and send it off again," Knoblach said. Schafer said the repeater could be used indefinitely "unless it lands in a lake or gets run over by a truck."

After the electronic equipment is released, the balloons rise and expand with the drop in air pressure until they burst. Knoblach said the balloons cost about $55 each.

Schafer said it costs about $250,000 to build one cellular tower in North Dakota, and many remote areas don't have enough customers to pay for it.

"The nice thing is that we don't have to weld a bunch of steel together to build a tower," Schafer said. "We just let these babies go."

Weston Henderek, a senior wireless analyst with Current Analysis of Sterling, Va., said he was not aware of a similar system of using balloons to provide wireless relays.

"It's difficult to say whether it's a pie-in-the-sky idea or if it will actually work," he said. "It's one of those cutting-edge type of things that people are starting to look at. It will be interesting to see how the testing pans out."

At the height of the Internet boom a few years ago, several companies looked at providing broadband or cell phone service from manned or unmanned blimps and aircraft.

So far, none of those plans have fully materialized, but GlobeTel Communications Corp. of Fort Lauderdale, Fla., has signed contracts to provide the nation of Colombia with unmanned communications blimps that would hover 10 to 13 miles up.

In North Dakota, plans call for the service to be sold wholesale to existing wireless carriers.

The state government is an "interested observer," said Jerry Fossum, the telecommunications director for the state Information Technology Department.

"It's certainly a possible solution to some of our demographic problems of a lot of space and not a lot of people," Fossum said. "I hope it works."