Eye in the Sky: Pentagon Tests New Spy Plane

EDWARDS A.F.B., Calif., Jan. 23, 2011— -- High over the Mojave desert, the Pentagon has been quietly testing a new generation of unmanned plane that flies higher, soars longer and runs greener than anything in the Pentagon's arsenal.

"This will really change the way we think about aviation," Assistant Secretary of Defense for Research and Engineering Zachary Lemnios told ABC News. "And it's going to open up an entirely new future."

The Global Observer, made by Monrovia, Calif.-based AeroVironment Inc., is bigger than a 767, flies in the stratosphere up to 65,000 feet, twice as high as Mount Everest -- out of sight and out of range of most anti-aircraft missiles. From there it will be able to see 600 miles in every direction, enough to cover the entire country of Afghanistan.

Earlier this month, the manufacturer gave ABC News an exclusive look, including video of the first test of a plane, which is powered entirely by liquid hydrogen fuel -- light enough to power the drone for a week at a time, far longer than anything in use today.

"It uses hydrogen for fuel, which has three times the energy density of gasoline, which enables it to fly much longer and at much lower costs and -- oh, by the way, has zero emissions," AeroVironment CEO Tim Conver told ABC News in an interview at the plane's hangar at Edwards Air Force Base in California.

It emits only water vapor.

The aircraft weighs about as much as a large SUV, but in order for it to fly so high for so long, the wing span has to be enormous -- about half a football field. That way even when you can't see it, it can see you.

AeroVironment is best known for electric car chargers and hand-launched, 1- to 2-foot-long unmanned aircraft -- some, like the Switchblade, lethal.

"It turns into a guided missile," AeroVironment's Steve Gitlin said, "and it'll follow the target if the target moves."

The new drone takes that unmanned capability much further, doing the work of a satellite for just tens of millions of dollars -- some analysts say it would cost about $30 million -- compared with hundreds of millions to $1 billion for a satellite. Unlike satellites, it can be up within hours and has the ability to instantly reposition.