Saturn C-4

{{Short description|Proposed NASA super-heavy-lift rocket}}

{{Infobox rocket

|image =Early Saturn rocket on pad.jpg

|caption =Saturn C-4B on pad

|name = Saturn C-4

|function = LEO and Lunar launch vehicle

|manufacturer = {{plainlist|

• Boeing (S-IB)
• North American (S-II)
• Douglas (S-IV)}}

|country-origin = United States

|cpl = 43.5 million

|cpl-year = 1985

|height = {{cvt|269.0|ft|m}}

|diameter = {{cvt|320|in|m}}

|mass = {{cvt|1,023,670|lb|kg}}

|stages = 3

|capacities =

{{Infobox rocket/Payload

|location= LEO

|kilos = {{cvt|218,000|lb|kg}}

}}

{{Infobox rocket/Payload

|location= TLI

|kilos = {{cvt|70,000|lb|kg}}

}}

|family = Saturn

|derivatives =

|comparable = Saturn V

|status = Proposed (1962)

|sites = planned SLC 37, LC-39; Kennedy Space Center

|stagedata=

{{Infobox rocket/Stage

|type = stage

|stageno = First

|name = S-IB-4

|length = {{cvt|113.10|ft|m}}

|diameter = {{cvt|320|in|m}}

|empty = {{cvt|149,945|lb|kg}}

|gross = {{cvt|1,599,433|lb|kg}}

|engines = 4 Rocketdyne F-1

|thrust = {{cvt|6,000,000|lbf|kN}}

|burntime = 139 seconds

|SI = 265 sec (sea level)

|fuel = RP-1/LOX

}}

{{Infobox rocket/Stage

|type = stage

|stageno = Second

|name = S-II-4

|length = {{cvt|69.80|ft|m}}

|diameter = {{cvt|320|in|m}}

|empty = {{cvt|54,978|lb|kg}}

|gross = {{cvt|449,840|lb|kg}}

|engines = 4 Rocketdyne J-2

|thrust = {{cvt|800,000|lbf|kN}}

|burntime = 200 seconds

|SI = 300 sec (sea level)

|fuel = LH₂ / LOX

}}

{{Infobox rocket/Stage

|type = stage

|stageno = Third

|name = S-IVB

|length = {{cvt|61.6|ft|m}}

|diameter = {{cvt|21.7|ft|m}}

|empty = {{cvt|29700|lb|kg}}

|gross = {{cvt|271000|lb|kg}}

|engines = 1 Rocketdyne J-2

|thrust = {{cvt|225,000|lbf|kN}}

|burntime = 165 + 335 seconds (2 burns)

|SI = {{convert|421|isp}}

|fuel = LH₂ / LOX

}}

}}

The Saturn C-4 was the fourth rocket in the Saturn C series studied from 1959 to 1962. The C-4 design was proposed in 1960 for a three-stage launch vehicle that could launch {{cvt|218,000|lb|kg|disp=flip}} to low Earth orbit and send {{cvt|70,000|lb|kg|disp=flip}} to the Moon via trans-lunar injection. It met the initial requirements for a lunar orbit rendezvous and lunar landing mission.{{cite web |url=http://www.astronautix.com/lvs/saturnc4.htm |title=Saturn C-4 |publisher=Astronautix.com |accessdate=8 June 2012 |url-status=dead |archiveurl=https://web.archive.org/web/20120617183721/http://www.astronautix.com/lvs/saturnc4.htm |archivedate=17 June 2012 }}

It would have consisted of three stages; an S-IB-4 first stage, a S-II-4 second stage and a S-IVB third stage. The first and second stages were essentially four-engine variants of the stages that would be used on the Saturn V, while the IVB stage was actually used on both the Saturn V and the Saturn IB.

It would have been capable of sending the {{cvt|67,000|lb|disp=flip}} Apollo Command/Service Module into lunar orbit, but it would not have been able to carry the {{cvt|32,000|lb|disp=flip}} Apollo Lunar Module as well. Although NASA eventually used the lunar orbit rendezvous method to go to the Moon, it decided to use the larger Saturn V which would provide a reserve payload capacity.

A December 1961 version called Saturn C-4B would have consisted of a S-IC C-4B first stage, a S-II C-5A second stage and a S-IVB C-5A third stage.{{Cite web |date=2012-06-17 |title=Saturn C-4B |url=http://www.astronautix.com/lvs/satrnc4b.htm |access-date=2023-12-26 |archive-date=2012-06-17 |archive-url=https://web.archive.org/web/20120617174038/http://www.astronautix.com/lvs/satrnc4b.htm |url-status=bot: unknown }} It would have been capable of sending a 31,000 kg (68,000 lb) payload to a translunar trajectory.