Editing Apollo 9 (section)

=== Spacecraft, equipment and call signs ===
Apollo{{nbsp}}9 used CSM-104, the third Block II CSM to be flown with astronauts aboard. Apollo 8, lacking a lunar module, did not have docking equipment; Apollo{{nbsp}}9 flew the probe-and-drogue assembly used for docking along with other equipment added near the forward hatch of the CM; this allowed for rigid docking of the two craft, and for internal transfer between CM and LM.{{sfn|Mission Report|pp=A-1, inside back cover}} Had the switch in missions between Apollo{{nbsp}}8 and{{nbsp}}9 not occurred, the Earth-orbit mission would have flown CSM-103, which flew on Apollo 8.{{sfn|French & Burgess|pp=338–339}}

The Earth-orbit mission was originally supposed to use LM-2 as its lunar module, but the crew found numerous flaws in it, many associated with it being the first flight-ready lunar module off Grumman's production line. The delay occasioned by the switch in missions allowed LM-3 to be available, a machine the crew found far superior.{{sfn|French & Burgess|p=339}} Neither LM-2 nor LM-3 could have been sent to the Moon as both were too heavy; Grumman's weight reduction program for the LMs only became fully effective with LM-5, designated for Apollo 11.{{sfn|''Science News'' 1969-03-01|p=218}} Small cracks in LM-3's aluminum alloy structure due to stresses such as the insertion of a rivet proved an ongoing issue; Grumman's engineers continued working to fix them until the LM had to be mounted on the Saturn{{nbsp}}V in December 1968,{{sfn|''Science News'' 1969-03-01|p=219}} where it was housed inside the Spacecraft-Lunar Module Adapter, numbered as SLA-11A.<ref name = "hardware">{{cite web|title=Apollo/Skylab ASTP and Shuttle Orbiter Major End Items|date=March 1978|url=https://s3.documentcloud.org/documents/6473665/Apollo-Skylab-ASTP-and-Shuttle-Orbiter-Major-End.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://s3.documentcloud.org/documents/6473665/Apollo-Skylab-ASTP-and-Shuttle-Orbiter-Major-End.pdf |archive-date=2022-10-09 |url-status=live|publisher=[[NASA]]|page=11}}</ref> LM-2 never flew in space and is in the [[National Air and Space Museum]].<ref>{{cite web|url=https://airandspace.si.edu/collection-objects/lunar-module-2-apollo|publisher=[[National Air and Space Museum]]|title=Lunar Module LM-2|access-date=April 19, 2019|archive-date=January 15, 2020|archive-url=https://web.archive.org/web/20200115082343/https://airandspace.si.edu/collection-objects/lunar-module-2-apollo|url-status=dead}}</ref>

The Apollo astronauts were provided with early versions of the [[Sony Walkman]], portable [[cassette recorder]]s intended to allow them to make observations during the mission. The Apollo{{nbsp}}9 crew was the first to be allowed to bring music [[mixtape]]s, one each, that could be played in that device. McDivitt and Scott preferred [[easy listening]] and [[country music]]; Schweickart's [[cassette tape]] of [[classical music]] went missing until the ninth day of the ten-day mission, when it was presented to him by Scott.<ref>{{cite web|last=Hollingham|first=Richard|url=http://www.bbc.com/future/story/20130429-thirteen-space-music-firsts|publisher=[[BBC]]|title=Space music firsts|date=November 18, 2014|access-date=July 5, 2019}}</ref><ref>{{cite web|last=Hollingham|first=Richard|url=http://www.bbc.com/future/story/20190704-apollo-in-50-numbers-the-technology|publisher=[[BBC]]|title=Apollo in 50 numbers: The technology|date=July 5, 2019|access-date=July 5, 2019}}</ref>

After the [[Gemini 3]] craft was dubbed ''[[Molly Brown]]'' by Grissom, NASA forbade naming spacecraft.{{sfn|Shepard, Slayton, & Barbree|pp=227–228}} The fact that during the Apollo{{nbsp}}9 mission, the CSM and LM would separate and need different [[call sign]]s caused the Apollo{{nbsp}}9 astronauts to push for a change. In simulations, they began to refer to the CSM as "Gumdrop", a name inspired by the CM's appearance while in the blue protective wrapping in which it was transported from the manufacturer, and the LM as "Spider", inspired by the LM's appearance with landing legs deployed.{{sfn|Orloff|p=282}} Personnel in NASA public relations thought the names were too informal, but the call signs ultimately gained official sanction.{{sfn|French & Burgess|p=340}} NASA required more formal call signs for future missions, starting with Apollo 11.{{sfn|Scott & Leonov|p=234}}

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File:Lunar Module 3 arrives at KSC aboard Super Guppy (KSC-68PC-85).jpg|alt=cased LM on airplane in hangar|LM-3 arrives at KSC, June 1968
File:Apollo 9 backup crew (S68-55255).jpg|alt=Blue command module Gumdrop|Apollo{{nbsp}}9 backup crew training in ''Gumdrop''
</gallery>