Editing Apollo 4 (section)

==Equipment==
[[File:S67-36022.jpg|thumb|left|alt=A conical spacecraft is maneuvered atop a rocket|CSM-017 is moved into position.]]

Apollo 4 carried CSM-017, a Block{{nbs}}I design of the command and service modules meant for testing and for Apollo's early Earth orbit flights. Unlike the Block{{nbs}}II spacecraft which would go to the Moon, it lacked the capability to dock with a [[lunar module]] (LM).<ref name="Brooks Apollo 4" /> CSM-017 was made up of command module CM-017 and service module SM-020.<ref name = "cm" /> CM-017 was the second fully-functional CM to be delivered to NASA; the first, CM-012, was designated for Apollo{{nbs}}1, and was severely damaged in the fire.<ref name = "fire" /> SM-020 was originally to be used in CSM-020, slated for the second Saturn{{nbs}}V test, but this changed after SM-017, which was intended to be part of CSM-017, was damaged in an explosion and was scrapped.<ref name = "cm">{{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|publisher=[[NASA]]|page=10, 15}}</ref>

Several significant Block II modifications were made to CSM-017 for certification purposes, since no Block{{nbs}}II spacecraft would fly without a crew.<ref name="Brooks Apollo 4">[[#Brooks|Brooks 1979]], [http://www.hq.nasa.gov/office/pao/History/SP-4205/ch9-5.html "''Apollo 4'' and Saturn V"] {{Webarchive|url=https://web.archive.org/web/20161107133918/http://www.hq.nasa.gov/office/pao/History/SP-4205/ch9-5.html |date=November 7, 2016 }}, Ch. 9-5</ref> These included upgrading the heat shield to Block{{nbs}}II standards, using a Block{{nbs}}II CM-to-SM umbilical connector, and installing Block{{nbs}}II-style VHF and [[Unified S-band|S-band]] antennae. Additionally, there were modifications to the CM's hatch.{{sfn|Press Kit|p=19}} The fact that the spacecraft hatch could not be readily opened in case of emergency had trapped the Apollo{{nbs}}1 astronauts in the fire that took their lives, and led to a redesign of the hatch. The new hatch was not scheduled to fly until the second Saturn{{nbs}}V test ([[Apollo&nbsp;6]]), but its seals were to be flight-qualified on Apollo{{nbs}}4{{snd}}the hatch window was replaced with a test panel simulating the seals and exterior heat shield. The heat shield was upgraded to Block{{nbs}}II standards since Apollo{{nbs}}4's high-speed re-entry into Earth's atmosphere was intended to simulate a return from the Moon.{{sfn|Press Kit|pp=2, 19–20}} Special equipment had been installed to allow Mission Control to operate the CSM's systems remotely, and there was a camera that would automatically take pictures out of one of the CM's windows on its final orbit.{{sfn|Press Kit|pp=18–19}} Since Apollo{{nbs}}4 carried no crew the CM lacked couches, controls and displays.<ref name = "register" />

A Lunar Module Test Article, LTA-10R, was carried, and remained inside the Spacecraft–LM Adapter, numbered as SLA-8, on the third stage of the Saturn{{nbs}}V throughout its flight. The LTA consisted of a flight-type descent stage lacking landing gear, with its fuel and oxidizer tanks containing a mixture of water, [[Ethylene glycol|glycol]], and [[freon]]. There was an ascent stage mockup atop it, made of aluminum with ballast, and having no flight systems. The SLA and LTA were instrumented to measure stress on them as the Saturn{{nbs}}V made its way to orbit.<ref name = "cm" />{{sfn|Press Kit|p=20}} LTA-10R would be destroyed when the S-IVB re-entered the atmosphere.{{sfn|Press Kit|p=3}}
[[File:Apollo 4 on the night before launch, Kennedy Space Center, Florida, 1967.jpg|thumb|right|upright|alt=Night view of a rocket on a launch pad|Apollo 4 on the launch pad]]

Apollo 4 was the first flight of a Saturn{{nbs}}V. At the time, it was the largest launch vehicle to ever attempt a flight.{{sfn|Reynolds 2002|pp=81–82}} This mission was the first time NASA used "all-up" testing, requiring that each stage of the launch vehicle work and that the vehicle carry a working spacecraft; a decision that goes back to late 1963.{{sfn|Cadbury 2006|p=274}} Mueller, the head of the NASA Office of Manned Space Flight at that time, was a [[Systems engineering|systems engineer]] who previously worked on military missile projects. He had recognized that all-up testing was successfully used to rapidly develop the Air Force's [[LGM-30 Minuteman|Minuteman ICBM]] program, and thought it could be used to meet Apollo's schedule.{{sfn|Murray & Cox 1989|pp=156–162}} In a 1963 memo he ordered that both the first Saturn{{nbs}}IB flight and the first Saturn{{nbs}}V flight be uncrewed, that each stage be fully functional, and that each carry a working spacecraft. The second flight of each type of rocket would also be an uncrewed test flight, and the third flight would be crewed.{{sfn|Bilstein 1996|p=349}} Previously, the way [[Wernher von Braun]]'s team at the [[Marshall Space Flight Center]] tested new rockets was by testing each stage incrementally.{{sfn|Murray & Cox 1989|pp=156–162}} The Saturn{{nbs}}V would be tested all at once, with all stages live and fully flight-worthy, including an Apollo CSM.{{sfn|Cadbury 2006|p=274}} This decision dramatically streamlined the program's test flight phase, eliminating four missions, but it required everything to work properly the first time.{{sfn|Cadbury 2006|p=274}} Apollo program managers had misgivings about all-up testing but agreed to it with some reluctance since incremental component tests would inevitably push the lunar landing mission past the 1970 goal.{{sfn|Neufeld 2007|pp=388–389, 400}}