Stealthy Supersonic

The F-35, the military’s next-generation fighter jet that's currently under development, has begun its first flight tests carrying external missiles at Edwards Air Force Base in the Mojave Desert.

The stealthy, supersonic fighter, built by Lockheed Martin Corp., has been undergoing tests since its first flight in late 2006.

The F-35, known as the Joint Strike Fighter, will be used jointly by the Navy, Marines and Air Force. Three versions of the F-35 are being built -- one that can operate off aircraft carriers, one capable of short takeoffs and vertical landings, and a conventional fighter jet.

All three F-35 variants will be built on the same production line at Lockheed's plant in Fort Worth, Texas. The center fuselage sections will be made by Northrop Grumman Corp. at Plant 42 in Palmdale.

Currently, the F-35 order is the Pentagon's costliest program going; the Defense Department has plans to buy 2,443 of the aircraft at a cost of $382 billion.