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 . Early flights . The U - 2 was developed by Lockheed Aircraft Corporation for the CIA to perform 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 . Lockheed developed their own expertise in RCS techniques . A small group headed by L . D . MacDonald included chemist Mel George , physicist Edward Lovick , and other scientists and engineers . Anti - radar techniques . The radar cross section ( RCS ) of an object is a measure of how much electromagnetic ( EM ) energy is reflected by an object , expressed as an area , typically square meters . The RCS of an object is a function of the object ' s size , shape , and materials . It also varies depending upon the frequency of the EM energy . Because long distance search / acquisition radars use different frequencies than short range fire control radars , a variety of techniques would have to be used to protect the U - 2 . All parts of the aircraft created reflections — the fuselage , tail , wings , engine inlets and exhaust . The anti - radar techniques investigated fell into two categories , either absorbing the radar energy or creating reflections that interfered with the reflections from the aircraft . Wallpaper . Purcell ' s first concept was an absorber material to be placed on the U - 2 ' s fuselage . Developed by the Lincoln Lab team and Lockheed , it became known as " Wallpaper . " It consisted of a conductive pattern printed on a flexible sheet that was then adhered to the aircraft . It was intended to be effective against the higher frequency radars . Trapeze . To reduce low - frequency ( 70 MHz ) reflections from the leading and trailing edges of the wings , a wire was placed parallel to and ahead of each wing ' s leading edge and another parallel to and behind each wing ' s trailing edge . To anchor the outboard end of each wire , a fiberglass pole was attached to each wingtip to give anchor points ahead and behind the wings . Each wire then ran from the front end of each pole to the slipper tank ( which projected in front of the wing ) and from the slipper tank to the fuselage . Behind each wing , a wire ran from the back end of the fiberglass pole to the fuselage . The horizontal stabilizer was treated in a similar manner . To protect the engine inlets , another wire ran diagonally from the nose to the slipper tank on each wing . This scheme was called " Trapeze . " Wires . To reduce low - frequency reflections from the fuselage and vertical stabilizer , wires were strung horizontally from the nose of the aircraft to the tail , and horizontally from the leading edge to the trailing edge of the vertical stabilizer . Ferrite beads were placed on the wires to tune them to the expected frequencies . This technique was called simply , " Wires . " Cost of stealth . The disadvantage of Wallpaper was that it was a thermal insulator and trapped heat in the fuselage . Initially it was applied to the upper and lower surfaces , but after the heating problem was recognized , it was applied only to the lower half of the fuselage . Nevertheless , the overheating was to prove fatal . On 2 April 1957 pilot Robert Sieker was conducting a test flight with Wallpaper applied to the U - 2 prototype , Article 341 . The heat buildup caused the engine to stall . Without power to maintain cockpit pressurization , the faceplate on Sieker ' s helmet popped open and he lost consciousness . Uncontrolled , the U - 2 went into a flat spin . Sieker recovered and bailed out , but at too low an altitude and he was killed . The effect of the Wires and Trapeze installations was increased drag . This cost the U - 2 5 , 000 feet in altitude and 20 % in range . The pilots were not enthusiastic about the reduced performance , nor in flying an aircraft that one of them likened to being " wired like a guitar . " Operational flights . On 6 May 1957 , Bissell reported to the President about the progress being made , saying that in operational missions , " the majority of incidents would go undetected . " In July the first " dirty bird " arrived at an operational detachment . The first mission of a " Covered Wagon , " as they were also known , took place on 21 July 1957 . In all , there were nine flights of the treated aircraft . By May 1958 , it had become apparent that the system was not effective , and its use ended . Follow - on . By the fall of 1957 , only months after the first deployment of a dirty bird , it had become obvious to Bissell and the scientific team that the treatments would only have a marginal effect on tracking , and that a new aircraft would be needed . By designing in anti - radar features from the beginning , it was hoped that the follow - on aircraft would escape detection . Conclusions . Bissell and his Air Force assistant , Col . Jack Gibbs , had been in discussions with aircraft and materials manufacturers , as well as various laboratories in an effort to understand what materials and designs might succeed . On 4 December 1957 , Bissell conducted a meeting at which the various techniques were summed up : Project GUSTO . A large number of people had become aware of Project RAINBOW . To reduce the spread of information about the follow - on , the work was moved into a new project . Called " GUSTO , " only those with a need to know were cleared into it . The end result of GUSTO would be the Lockheed A - 12 OXCART .