GPS FAILURE?

We rely on them to get us places, but the GPS you trust could lead you astray.

The government must do something soon, or the satellites that direct your GPS will start failing as soon as next year.

Fort Worth, Texas reader J.R. Martinez doesn't use old-fashioned maps to figure out where he's going anymore.

A GPS on his Blackberry tells him how to get there.

GPS devices are big sellers these days.

"They are converging a lot of devices into one," said Mark Guthrie of Best Buy.

Want a pizza? The latest GPS gadgets connect to Google to show you what's close.

It'll tell you how to get there, too, and even areas to avoid.

How does GPS know exactly where you are?

A government array of 31 satellites pinpoints your location.

But now a new fear, that those satellites are aging and in danger of falling.

A report by the investigative arm of Congress warns of "an increased likelihood that in 2010, as old satellites begin to fail, the overall GPS constellation will fall below the number of satellites required."

Not to worry, says the U.S. Air Force office that runs the program.

Firing back at critics, the Air Force says the issue is under control, and that there is only a "small risk" that the system will suffer.

The Air Force says it's busy preparing to launch new satellites.

The GAO report says its timetable is optimistic.

So, while nobody expects GPS to fail overnight, there are big concerns about its future.