Two Cobra Ball aircraft on the flightline at Offutt Air Force base, Nebraska in 2001.

The RC-135S Cobra Ball is a measurement and signature intelligence MASINT collector equipped with special electro-optical instruments designed to observe ballistic missile flights at long range. The Cobra Ball monitors missile-associated signals and tracks missiles during boost and re-entry phases to provide reconnaissance for treaty verification and theater ballistic missile proliferation. The aircraft are extensively modified C-135Bs.[4] The right wing and engines are traditionally painted black to reduce sun glare for tracking cameras.