{{Short description|First stage of the Saturn IB rocket}} {{Infobox rocket stage | image = Saturn IB 1st stage.jpg | caption = Diagram of the S-IB first stage of the Saturn IB rocket | name = S-IB | manufacturer = Chrysler<ref name=":0"></ref> | country = United States | rockets = Saturn IB (stage 1) | height = {{convert|25.5|m|ft|abbr=on}} | diameter = {{convert|6.6|m|ft|abbr=on}} | mass = {{convert|448,648|kg|lb|abbr=on}} | propmass = <!--propellant mass in kilograms, use {{convert}}--> | empty = <!--dry mass in kilograms, use {{convert}}--> | family = <!--if a member of a family of stages--> | derived_from = S-I | derivatives = <!--if derivative stages--> | status = Retired | launches = 9 | success = 9 | fail = <!--number of times stage itself has failed--> | first = February 26, 1966 | last = July 15, 1975 | stagedata = {{Infobox rocket/stage | engines = 8 H-1 engines | thrust = {{convert|7.1|MN|lbf|abbr=on}} | SI = {{convert|296|isp|abbr=on}} | burntime = 155 seconds | fuel = RP-1/LOX }} }}{{Commons category|Saturn S-IB}} The '''S-IB stage''' was the first stage of the Saturn IB launch vehicle, which was used for Earth orbital missions.<ref>{{cite web |last=Wade |first=Mark |date=2001 |title=Saturn IB |url=http://www.astronautix.com/stages/saturnib.htm |url-status=dead |archive-url=https://web.archive.org/web/20020504033203/http://www.astronautix.com/stages/saturnib.htm |archive-date=May 4, 2002 |publisher=Encyclopedia Astronautica}}</ref> It was an upgraded version of the S-I stage used on the earlier Saturn I rocket and was composed of nine propellant containers, eight fins, a thrust structure assembly, eight H-1 rocket engines, and many other components. It also contained the ODOP transponder. The propellant containers consisted of eight Redstone-derived tanks (four holding liquid oxygen (LOX) and four holding RP-1) clustered around a Jupiter rocket-derived tank containing LOX. The four outboard engines gimballed to steer the rocket in flight, which required a few more engine components. The S-IB burned for nearly 2.5 minutes before separating at an altitude of {{convert|42|mi|km}}.

==Specifications== *Height: {{convert|80.17|ft|m|abbr=on}} *Diameter: {{convert|21.42|ft|m|abbr=on}} *Number of fins: 8 *Finspan: {{convert|39.42|ft|m|abbr=on}} *Engines: 8 Rocketdyne H-1 *Thrust: {{convert|1,600,000|lbf|kN|abbr=on}} *Fuel: RP-1 (Refined kerosene) 41,000 US gal (155 m<sup>3</sup>) *Oxidizer: Liquid oxygen (LOX) 66,277 US gal (251 m<sup>3</sup>) nominal capacity including 1.5% ullage volume (43,284 US gal / 163 m<sup>3</sup> in four outer tanks plus 22,993 US gal / 87 m<sup>3</sup> in center tank<ref>{{Cite journal |date=1972-09-30 |title=Skylab Saturn IB Flight Manual (MSFC-MAN-206) |url=https://ntrs.nasa.gov/citations/19740021163 |journal=Technical Memorandum |language=en |publisher=NASA Marshall Spaceflight Center}}</ref>) *Burn time: 2.5 min *Burnout altitude: {{convert|37|nmi|km|abbr=on}}

== Stages built == '''Apollo flights:'''<ref name=":0">{{cite web |last=Kyle |first=Ed |date=December 6, 2012 |title=Saturn IB History |url=http://www.spacelaunchreport.com/satstg2.html |url-status=usurped |archive-url=https://archive.today/20130104180922/http://www.spacelaunchreport.com/satstg2.html |archive-date=January 4, 2013 |accessdate=2014-09-01 |website=Space Launch Report . . . Saturn Vehicle History}}</ref>

* S-IB-1: Launched 2/26/1966 on suborbital AS-201 mission. * S-IB-3: Launched 7/5/1966 as AS-203 orbital test mission. * S-IB-2: Launched 8/25/1966 on suborbital AS-202 test mission. * S-IB-4: Launched 1/22/1968 on Apollo 5 orbital mission. * S-IB-5: Launched 10/11/1968 on crewed Apollo 7 orbital mission.

'''Post-Apollo Flights:<ref name=":0" />'''

* S-IB-6: Launched 5/25/1973 on Skylab-2 orbital mission. * S-IB-7: Launched 7/23/1973 on Skylab-3 orbital mission. * S-IB-8: Launched 11/16/1973 on Skylab-4 orbital mission. * S-IB-10: Launched 7/15/1975 on ASTP orbital mission.

'''Hardware Not Flown:<ref name=":0" />'''

* S-IB-9: Stacked on MLP ready to fly as Skylab backup. Now on display at Kennedy Space Center Visitor Complex. * S-IB-11: Flight not assigned. Displayed vertically at Alabama Welcome Center until late 2023, when it was dismantled due to weathering.<ref>{{cite web |url=https://www.al.com/news/2023/09/historic-alabama-welcome-center-rocket-dismantling-begins.html|title=Historic Alabama welcome center rocket dismantling begins|access-date=2023-09-20}}</ref> * S-IB-12: Flight not assigned. Presumed scrapped at Marshall Space Flight Center in late 1970s. * S-IB-13: Hardware scrapped. * S-IB-14: Hardware scrapped. * S-IB-15: Not built, cancelled by NASA in 1968. * S-IB-16: Not built, cancelled by NASA in 1968.

== Proposed variants == Besides the version flown as the Saturn IB stage, other versions were proposed for several vehicle concepts:<ref>{{Cite web |title=S-I stage |url=http://astronautix.com/s/s-istage.html |access-date=2025-11-18 |website=astronautix.com}}</ref>

=== Saturn S-IB-2 === The S-IB-2 stage was studied in 1960 to power the Saturn C-3.<ref>{{Cite web |title=Saturn C-3 |url=http://astronautix.com/s/saturnc-3.html |access-date=2025-11-17 |website=astronautix.com}}</ref> It was planned to be larger (with a height of 34.50&nbsp;m and a diameter of 8.25&nbsp;m), powered by two F-1 engines developing {{convert|3|e6lbf|MN}} of thrust, with a fueled mass of {{convert|1.6|e6lb|t}}.<ref>{{Cite web |title=Saturn S-IB-2 |url=http://astronautix.com/s/saturns-ib-2.html |access-date=2025-11-17 |website=astronautix.com}}</ref>

=== Saturn S-IB-4 === The S-IB-4 stage was studied in 1960 to power the Saturn C-4, using four F-1 engines.<ref>{{Cite web |title=Saturn S-IB-4 |url=http://astronautix.com/s/saturns-ib-4.html |access-date=2025-11-18 |website=astronautix.com}}</ref>

=== Saturn S-IB-A === The S-IB-A stage was studied in 1965 to power the Saturn IB-A and Saturn IB-B, using eight H-1c engines.<ref>{{Cite web |title=Saturn S-IB-A |url=http://astronautix.com/s/saturns-ib-a.html |access-date=2025-11-18 |website=astronautix.com}}</ref>

=== Saturn IB-11 === The IB-11 stage was studied in 1966 to power the Saturn INT-11, Saturn INT-13 and Saturn INT-14, using eight H-1b engines and UA1207 solid boosters.<ref>{{Cite web |title=Saturn IB-11 |url=http://astronautix.com/s/saturnib-11.html |access-date=2025-11-18 |website=astronautix.com}}</ref>

=== Saturn IB-15 === The IB-15 stage was studied in 1966 to power the Saturn INT-15, using eight H-1b engines and Minuteman first-stage strap-ons.<ref>{{Cite web |title=Saturn IB-15 |url=http://astronautix.com/s/saturnib-15.html |access-date=2025-11-18 |website=astronautix.com}}</ref>

=== Saturn S-1B-4 === The S-1B-4 stage was studied in 1966 to power the Saturn INT-12, using four H-1b engines and UA1205 solid boosters.<ref>{{Cite web |title=Saturn S-1B-4 |url=http://astronautix.com/s/saturns-1b-4.html |access-date=2025-11-18 |website=astronautix.com}}</ref>

==References== {{Reflist}}

Category:Rocket stages Category:Saturn IB Category:Saturn B-1 Category:Saturn A-2