Project RAINBOW

  Origins and Context

Project RAINBOW emerged in 1951 as a classified program to reduce the radar signature of reconnaissance aircraft.¹ The program gained urgency after Soviet radar systems demonstrated the ability to track high-altitude aircraft.²

  Program Structure

The U.S. Navy Research Laboratory led technical development, collaborating with CIA and Lockheed engineers.³ The program tested various radar-absorbent materials and surface treatments on operational aircraft.⁴

  Technical Capabilities

RAINBOW developed ferrite-based coatings and wire mesh configurations to minimize radar returns.⁵ The modifications reduced the U-2's radar cross-section but impacted aircraft performance and maintenance.⁶

  Legacy

The program established foundational radar cross-section reduction techniques.⁷ These advances influenced later stealth aircraft development, including the A-12 OXCART and F-117.⁸

  References

1. nrl.navy.mil ↩

2. cia.gov ↩

3. airandspace.si.edu ↩

4. apps.dtic.mil ↩

5. ieeexplore.ieee.org ↩

6. afhra.af.mil ↩

7. history.navy.mil ↩

8. nasic.af.mil ↩