Editing SM-65 Atlas (section)

===Engines===
The booster engine consisted of two large thrust chambers. The Atlas A/B/C/D had a single turbopump assembly and gas generator driving both booster engines; the A/B/C had an interim engine with lower thrust while the D-series had the full-up engines delivering 303,000 pounds of thrust.<ref name="McCutcheon"/> On the Atlas E/F, each booster engine had a separate pump and gas generator. Later space launcher variants of the Atlas used the MA-5 propulsion system with twin turbopumps on each booster engine, driven by a common gas generator.<ref name="Brugge"/> The boosters were more powerful than the sustainer engine and did most of the lifting for the first two minutes of flight. In addition to pitch and yaw control, they could also perform roll control in the event of a vernier failure. The sustainer engine on all Atlas variants consisted of a single thrust chamber with its own turbopump and gas generator, which also powered two small pressure-fed vernier engines.<ref name="McCutcheon"/> The verniers provided roll control and final velocity trim. The total sea level thrust of all five thrust chambers was 360,000&nbsp;[[Pound (force)|lb<sub>''f''</sub>]] (1,600&nbsp;[[Newton (unit)|kN]]) for a standard Atlas D. Atlas E/F had 375,000 pounds of thrust. Total sea level thrust for these three-engine Atlas Es and Fs was 389,000&nbsp;lb<sub>f</sub> (1,730&nbsp;kN).<ref name="FEWarren">{{cite web|archive-url=https://web.archive.org/web/20080509071108/http://www.warrenmuseum.com/atlas.htm |archive-date=May 9, 2008|url=http://www.warrenmuseum.com/atlas.htm|title=Atlas SM-65|publisher=FE Warren Museum}}</ref> [[Launch vehicle|Launcher]] variants of the Atlas often had performance enhancements to the engines.<ref name="McCutcheon" />