Editing SM-65 Atlas (section)

===SM-65A Atlas===
{{main | SM-65A Atlas }}
[[File:Atlas missile test launch.jpg|thumb|150x150px|Atlas, test number 449,  Air Force Missile Test Center.]]
The [[Convair]] '''X-11'''/'''SM-65A Atlas'''/'''Atlas A''' was the first full-scale prototype of the Atlas missile, first flying on 11 June 1957.<ref name="EA">{{cite web |url=http://www.astronautix.com/lvs/atlasa.htm |title=Encyclopedia Astronautica – Atlas A |publisher=Astronautix.com |access-date=19 July 2013 |url-status=dead |archive-url=https://web.archive.org/web/20130522064526/http://www.astronautix.com/lvs/atlasa.htm |archive-date=22 May 2013 |df=dmy-all }}</ref> It was a test model designed to verify the structure and propulsion system, and had no sustainer engine or separable stages. The first three Atlas A launches used an early Rocketdyne engine design with conical thrust chambers and only 135,000 pounds of thrust. By the fourth Atlas test, they were replaced by an improved engine design that had bell-shaped thrust chambers and 150,000 pounds of thrust.

There were eight Atlas A test flights, conducted in 1957–58, of which four were successful. All were launched from [[Cape Canaveral Air Force Station]], at either [[Cape Canaveral Air Force Station Launch Complex 12|Launch Complex 12]] or [[Cape Canaveral Air Force Station Launch Complex 14|Launch Complex 14]].<ref name="EA" />