On Wednesday, the Department of Defense announced that it has awarded a sizable Air Force contract to Lockheed Martin's (LMT -0.55%) Aeronautics division. Valued at $6.9 billion, the contract calls upon Lockheed to perform "modernization" work on the F-22 Raptor fighter jet.

The F-22, America's first so-called "fifth-generation" stealth fighter jet, has already cost  close to $80 billion to develop and build. Although 187 of the jets are currently in the Air Force's inventory , the F-22 has never once been flown in combat.

Last year, the F-22 flew into a maelstrom of criticism,  when it was reported that pilots of the jet were experiencing problems breathing while in flight, leading to multiple groundings  of the plane.