 Air Defense Command took over the remaining RB-57Ds to act as high-altitude targets for the supersonic interceptor force.Martin modified the wings to extend their service life.Fitted out with electronic countermeasures, the 4677th Defense Systems Evaluation Squadron at Hill AFB, Utah, was formed to operate 12 of the 20 RB-57Ds to fly training missions against continental Radar defense installations as electronic "aggressor" aircraft The upgrades to the electronic countermeasures to challenge the ADC interceptor crews resulted in these aircraft being designated EB-57Ds
Some were used by NASA for high-altitude flight testing and terrain mapping.