Editing Apollo 4 (section)

{{Short description|First test flight of the Apollo Saturn V rocket}}
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{{Infobox spaceflight
| name                  = Apollo 4
| image                 = File:Apollo 4 Launch - GPN-2000-000044.jpg
| image_caption         = The first flight of a Saturn{{nbs}}V launch vehicle
| mission_type          = Uncrewed Earth orbital CSM flight ([[List of Apollo missions#Alphabetical mission types|A]])
| operator              = [[NASA]]
| COSPAR_ID             = 1967-113A (command and service modules)<br>1967-113B (S-IVB){{sfn|Orloff & Harland 2006|p=124}}
| SATCAT                = 3032
| mission_duration      = 8 hours, 36 minutes, 59{{nbs}}seconds
| orbits_completed      = 3
| spacecraft            = [[Apollo command and service module|Apollo CSM]]-017<br>Apollo LTA-10R
| manufacturer          = [[North American Rockwell]]
| launch_mass           = {{convert|81253|lb|kg|order=flip}}
| landing_mass          =
| launch_date           = {{start-date|November 9, 1967, 12:00:01|timezone=yes}}{{nbs}}UTC 
| launch_rocket         = [[Saturn V]] SA-501
| launch_site           = [[Kennedy Space Center|Kennedy]] [[Kennedy Space Center Launch Complex 39|LC-39]][[Kennedy Space Center Launch Complex 39A|A]] 
| landing_date          = {{end-date|November 9, 1967, 20:37:00|timezone=yes}}{{nbs}}UTC 
| landing_site          = North Pacific Ocean<br>{{Coord|30|06|N|172|32|W|type:event|name=Apollo 4 splashdown}}
| recovery_by           = {{USS|Bennington|CV-20|6}}
| orbit_epoch           = November 9, 1967<ref name=satcat>{{cite web|last=McDowell|first=Jonathan|title=Master Satellite List|url=http://planet4589.org/space/log/satcat.txt|publisher=Jonathan's Space Pages|access-date=March 23, 2014}}</ref>
| orbit_reference       = [[geocentric orbit|Geocentric]]
| orbit_regime          = [[Highly elliptical orbit]]
| orbit_periapsis       = {{convert|-204|km|nmi|sp=us}}
| orbit_apoapsis        = {{convert|18092|km|nmi|sp=us}}
| orbit_inclination     = 31.9 degrees
| orbit_period          = 314.58 minutes (initial)
| apsis                 = gee
| previous_mission      = [[Apollo 1]]
| next_mission          = [[Apollo 5]]
| programme             = [[Apollo program]]
}}

'''Apollo 4''' (November 9, 1967), also known as '''SA-501''', was the uncrewed first test flight of the [[Saturn&nbsp;V]] launch vehicle, the rocket that eventually took astronauts to the [[Moon]]. The [[space vehicle]] was assembled in the [[Vehicle Assembly Building]], and was the first to be launched from [[Kennedy Space Center]] (KSC) in Florida, ascending from [[Kennedy Space Center Launch Complex 39|Launch Complex 39]], where facilities built specially for the Saturn{{nbs}}V had been constructed.

Apollo 4 was an "all-up" test, meaning all rocket stages and spacecraft were fully functional on the initial flight, a first for [[NASA]]. It was the first time the [[S-IC]] first stage and [[S-II]] second stage flew. It also demonstrated the [[S-IVB]] third stage's first in-flight restart. The mission used a Block{{nbs}}I [[command and service module]] modified to test several key Block{{nbs}}II revisions, including its [[heat shield]] at simulated lunar-return velocity and angle.

The launch was planned for early 1967, but delayed to November{{nbs}}9 because of problems with various elements of the spacecraft and difficulties during pre-flight testing. Additional inspections were also required after a fire killed the [[Apollo&nbsp;1]] crew in January 1967. 

The mission splashed down in the Pacific Ocean slightly less than nine hours after launch, having achieved its objectives. NASA considered the mission a complete success, proving that the Saturn{{nbs}}V worked, an important step towards achieving the main objective of landing astronauts on the Moon, and bringing them back safely, before the end of the 1960s.