* Astronomy

The Convair XSM-16A (later X-11) was the first testbed for what became the Atlas missile. Later the Convair X-12 became a second, more advanced testbed. A total of 12 X-11's were built and tested. The first three were involved in static tests only. X-11 Number 4 and 6, were destroyed in launch accidents. All others performed successful test flights. The test series began on June 11, 1957 and ended on June 3, 1958.
It was developed into the SM-65A Atlas, or Atlas A, which was the first full-scale prototype of the Atlas missile, which first flew on 11 June 1957. 
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