Project RAINBOW is the name of two separate alleged United States secret military projects in the 20th Century, both concerned with stealth and radar invisibility. At least one recent, anonymous, writer in the UFO/conspiracy underground has linked the two projects, though this is by no means considered a mainstream viewpoint.
- The near-mythical 1943 Philadelphia Experiment, denied by all official sources and considered fictitious by mainstream historians, but a major element of UFO lore.
- A project in the 1950s United States Air Force stealth technology program, involving wires and ferrite cores mounted on the fuselage of the Lockheed U-2 aircraft. This Project RAINBOW is attested by mainstream historians of military technology. The project was considered a failure at the time, though it may have influenced later developments in stealth technology.
- wikipedia: Project-Rainbow