The Atlas went in for a repeat performance on April 8 when Missile 48D, intended as the first closed-loop test of the AIG ( All Inertial Guidance System ), exploded on LC-11 almost as soon as it was released by the pad hold-down arms due to another episode of combustion instability, this time in the B-2 engine which backfired and ruptured from mechanical shock, starting a thrust section fire that led to the complete loss of the missile.
