Lockheed Have Blue was the code name for Lockheed's proof of concept demonstrator for a stealth fighter. Have Blue was designed by Lockheed's Skunk Works division, and tested at Groom Lake, Nevada. The Have Blue was the first fixed-wing aircraft whose external shape was defined by radar engineering rather than by aerospace engineering. The aircraft's faceted shape was designed to deflect electromagnetic waves in directions other than that of the originating radar emitter, greatly reducing its radar cross-section.