Editing Apollo 12 (section)

===Launch===
With President [[Richard Nixon]] in attendance, the first time a current U.S. president had witnessed a crewed space launch,{{sfn|Lattimer 1985|p=74}} as well as Vice President [[Spiro Agnew]],{{sfn|Harland 2011|p=91}} Apollo 12 launched as planned on November 14, 1969, from the Kennedy Space Center at 16:22:00&nbsp;[[UTC]] (11:22&nbsp;am&nbsp;[[Eastern Standard Time|EST]], local time at the launch site). This was at the start of a launch window of three hours and four minutes to reach the Moon with optimal lighting conditions at the planned landing point.{{sfn|Orloff & Harland 2006|p=329}}{{sfn|Press Kit|p=10}} There were completely overcast rainy skies, and the vehicle encountered winds of {{convert|151.7|kn||abbr=}} during ascent, the strongest of any Apollo mission.<ref>{{Cite web|url=https://history.nasa.gov/SP-4029/Apollo_18-15_Launch_Weather.htm|title=Launch Weather|publisher=[[NASA]]|access-date=January 7, 2021|page=279}}</ref> There was a NASA rule against launching into a [[cumulonimbus cloud]]; this had been waived and it was later determined that the launch vehicle never entered such a cloud.{{sfn|Orloff & Harland 2006|pp=329–330}} Had the mission been postponed, it could have been launched on November 16 with landing at a backup site where there would be no Surveyor, but since time pressure to achieve a lunar landing had been removed by Apollo 11's success, NASA might have waited until December for the next opportunity to go to the Surveyor crater.{{sfn|Harland 2011|pp=28, 30, 81}}

Lightning struck the Saturn V 36.5 seconds after lift-off, triggered by the vehicle itself. The static discharge caused a voltage transient that knocked all three fuel cells offline, meaning the spacecraft was being powered entirely from its batteries, which could not supply enough current to meet demand. A second strike at 52 seconds knocked out the "8-ball" [[attitude indicator]]. The [[telemetry]] stream at [[Christopher C. Kraft Jr. Mission Control Center#Houston (1965–present)|Mission Control]] was garbled, but the Saturn V continued to fly normally; the strikes had not affected the [[Saturn V instrument unit]] guidance system, which functioned independently from the CSM. The astronauts unexpectedly had a board red with caution and warning lights, but could not tell exactly what was wrong.{{sfn|Orloff & Harland 2006|pp=329–331}}<ref name="launch">{{cite web|date=March 27, 2020|editor-last=Woods|editor-first=W. David|title=Day 1, Part 1: Launch and Reaching Earth Orbit|url=https://history.nasa.gov/afj/ap12fj/01launch_to_earth_orbit.html#0000136|access-date=2021-03-03|work=Apollo 12 Flight Journal|publisher=NASA|editor-last2=Waugh|editor-first2=Lennox J.|df=mdy-all}}</ref>{{sfn|Harland 2011|pp=105–107}}

The [[Flight controller#EECOM|Electrical, Environmental and Consumables Manager]] (EECOM) in Mission Control, [[John Aaron]], remembered the telemetry failure pattern from an earlier test when a power loss caused a malfunction in the CSM signal conditioning electronics (SCE), which converted raw signals from instrumentation to data that could be displayed on Mission Control's consoles, and knew how to fix it.<ref name = "launch" /><ref>{{cite book |last1=Kranz |first1=Eugene F. |author-link1=Gene Kranz |last2=Covington |first2=James Otis |title=What Made Apollo a Success? |url=https://history.nasa.gov/SP-287/sp287.htm |access-date=November 7, 2011 |orig-year="A series of eight articles reprinted by permission from the March 1970 issue of ''Astronautics & Aeronautics'', a publication of the [[American Institute of Aeronautics and Astronautics]]." |year=1971  |publisher=NASA |location=Washington, D.C. |oclc=69849598 |id=NASA SP-287 |chapter=Flight Control in the Apollo Program |chapter-url=https://history.nasa.gov/SP-287/ch5.htm}} Chapter 5.</ref> Aaron made a call, "Flight, EECOM. Try SCE to Aux", to switch the SCE to a backup power supply. The switch was fairly obscure, and neither Flight Director Gerald Griffin, CAPCOM Gerald P. Carr, nor Conrad knew what it was; Bean, who as LMP was the spacecraft's engineer, knew where to find it and threw the switch, after which the telemetry came back online, revealing no significant malfunctions. Bean put the fuel cells back online, and the mission continued.<ref name = "launch" />{{sfn|Chaikin 1995|p=238}}{{sfn|Harland 2011|pp=107–109}} Once in Earth [[parking orbit]], the crew carefully checked out their spacecraft before re-igniting the S-IVB third stage for [[trans-lunar injection]]. The lightning strikes caused no serious permanent damage.{{sfn|Chaikin 1995|pp=240–241}}

Initially, it was feared that the lightning strike could have damaged the explosive bolts that opened the Command Module's parachute compartment. The decision was made not to share this with the astronauts and to continue with the flight plan, since they would die if the parachutes failed to deploy, whether following an Earth-orbit abort or upon a return from the Moon, so nothing was to be gained by aborting.{{sfn|Chaikin 1995|p=241}} The parachutes deployed and functioned normally at the end of the mission.{{sfn|Orloff & Harland 2006|p=338}}