The 3903rd Radar Bomb Scoring Group was a military evaluation unit under direct command of Strategic Air Command (SAC) headquarters for scoring simulated bomb runs using automatic tracking radar stations. Initially an Army Air Forces Base Unit (AAFBU) and then a squadron, the 3903rd RBS Group was personnel, assets, and detachments were redesignated the 1st Radar Bomb Scoring Group and then the 1CEVG Radar Bomb Scoring Division when the RBS Group merged with the in 1961, the year RBS Express trains began to be used for low-altitude Boeing B-52 Stratofortress operations..