The SM-65A Atlas, or Atlas A, also designated X-11 was the first full-scale prototype of the Atlas missile, which first flew on 11 June 1957. Unlike later versions of the Atlas missile, the Atlas A did not feature the stage and a half design. Instead, the booster engines were fixed in place, and the sustainer engine was omitted.
First launch attempt of an Atlas vehicle. Performance was normal until T+30 seconds when the missile lost thrust due to exhaust gases being sucked back into the boattail and burning through wiring. Range Safety issued the destruct command at T+50 seconds. The flight was considered a "partial success" because the Atlas's balloon skin had maintained its structural integrity until vehicle destruction.
3 kilometres (1.9 mi)
Loss of thrust followed by vehicle tumbling and RSO destruct at T+74 seconds due to overheating that led to gas generator failure.