Project Rainbow

Project Rainbow was the name given by the CIA to a research project aimed at reducing the radar cross-section of the Lockheed U-2 to reduce the chance that it would be detected and tracked by Soviet radars during its overflights of the USSR.

The U-2 was developed by Lockheed Aircraft Corporation for the CIA to perform aerial reconnaissance overflights of the Soviet Union. Project director Richard M. Bissell assured President Dwight Eisenhower that the aircraft's high altitude (70,000 feet) would render it invisible to Soviet radars. However, the earliest flights in July 1956 were, in fact, tracked. On 5 July, an A-100 "Kama" radar detected Carmine Vito as he flew over Smolensk, en route to Moscow. The operators even calculated his altitude as twenty kilometers (65,000 feet), which was later rejected by experts who did not believe that an aircraft could fly that high. SA-1 missiles were not kept at the air defense sites around Moscow, and no intercept was attempted.

In mid-August, Bissell assembled a group of advisors to begin work on solving the tracking problem. Among the group were Edwin H. Land, founder of the Polaroid Corporation and head of Project Three the Technological Capabilities Panel;Edward Purcell, a Nobel laureate physicist from Harvard; and Clarence L. "Kelly" Johnson, head of Lockheed Advanced Development Projects (ADP)—the Skunk Works.

The group conducted initial discussions. Then Land went to the MIT Lincoln Laboratory to recruit radar specialists for the work. The leader of the Lincoln Lab team was Franklin Rodgers, associate head of the radar division. Working in isolation from the rest of the lab, his group began trying to find ways to reduce the U-2's radar cross section. As their work progressed, they traveled to California to work with Lockheed and to various military bases to perform radar measurements of U-2s in flight.

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