The Boeing B-29 bomber, for instance, had 40, 540 different parts, and 1, 400 sub- contractors provided most of them.

ECONOMIST: The "dollar-a-year" men and what they achieved

Boeing received a contract in 2009 to fit the weapon on the U.S.'s B-2 Stealth Bomber.

WSJ: Pentagon Seeks Mightier Bomb vs. Iran