The X-35, Joint Strike Fighter from Lockheed Martin nears completion of flight testing at Edwards Air Force Base, Calif., in 2001. The JSF is being built in three variants: a conventional take-off and landing aircraft (CTOL) for the US Air Force; a carrier based variant (CV) for the US Navy; and a short take-off and vertical landing (STOVL) aircraft for the US Marine Corps and the Royal Navy. (U.S. Air Force photo)