Starting in the Second World War, radar technology came into widespread use both for detection and targeting of aircraft. Because of this, aeronautical engineers began searching for ways to make aircraft less "visible" to electronic tracking and weapon systems. The earliest stealth technologies consisted of coating aircraft with materials that would absorb rather than deflect a radar signal. In the late 1970s, designs incorporating this technology, as well as a unique fuselage shape designed to deflect radar away from its source, were prototyped. The first true stealth fighter, the Lockheed F-117A, flew for the first time on June 18, 1981. This fighter, incorporating the latest anti-radar and anti-thermal innovations, is capable of entering enemy territory, delivering its payload, and returning to base with little chance of detection. These unique, black aircraft served well in the Persian Gulf War in 1991, and have served as the basis for further development of stealth aircraft technology.