Editing Apollo Guidance Computer (section)

==Operation==
In the earlier [[Project Gemini]] program, the astronauts flew manually with [[control stick]]s. In the Apollo program however, the flight was controlled by the computer. The astronauts flew manually briefly during lunar landings.<ref name="agle199809">{{Cite magazine |last=Agle |first=D.C. |date=September 1998 |title=Flying the Gusmobile |url=https://www.airspacemag.com/flight-today/flying-the-gusmobile-218187/ |magazine=Air & Space |language=en |access-date=2018-12-15}}</ref> Each Moon flight carried two AGCs, one each in the [[Apollo command module|command module]] and the [[Apollo Lunar Module]], with the exception of [[Apollo 7]] which was an Earth orbit mission and [[Apollo 8]] which did not need a lunar module for its lunar orbit mission. The AGC in the command module was the center of its guidance, navigation and control (GNC) system. The AGC in the lunar module ran its [[Apollo PGNCS]] (primary guidance, navigation and control system), with the acronym pronounced as ''pings''.

[[File:Dsky.jpg|thumb|left|The display and keyboard (DSKY) interface of the Apollo Guidance Computer mounted on the control panel of the command module, with the flight director attitude indicator (FDAI) above]]
[[File:Agc verb-noun-list.jpg|thumb|left|Partial list of numeric codes for verbs and nouns in the Apollo Guidance Computer, printed for quick reference on a side panel]]

Each lunar mission had two additional computers:

* The [[Launch Vehicle Digital Computer]] (LVDC) on the [[Saturn V]] booster instrumentation ring
* the [[Abort Guidance System]] (AGS, pronounced ''ags'') of the lunar module, to be used in the event of failure of the LM PGNCS. The AGS could be used to take off from the Moon, and to rendezvous with the command module, but not to land.