The S-IB stage was the first stage of the Saturn IB launch vehicle, which was used for Earth orbital missions. 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 .

Specifications

• Height:

• Diameter:

• Number of fins: 8

• Finspan:

• Engines: 8 Rocketdyne H-1

• Thrust:

• Fuel: RP-1 (Refined kerosene) 41,000 US gal (155 m3)

• Oxidizer: Liquid oxygen (LOX) 66,277 US gal (251 m3) nominal capacity including 1.5% ullage volume (43,284 US gal / 163 m3 in four outer tanks plus 22,993 US gal / 87 m3 in center tank)

• Burn time: 2.5 min

• Burnout altitude:

Stages built

Apollo flights:

• 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: 

• 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:

• 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.

• 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:

Saturn S-IB-2

The S-IB-2 stage was studied in 1960 to power the Saturn C-3. It was planned to be larger (with a height of 34.50m and a diameter of 8.25m), powered by two F-1 engines developing of thrust, with a fueled mass of .

Saturn S-IB-4

The S-IB-4 stage was studied in 1960 to power the Saturn C-4, using four F-1 engines.

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.

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.

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.

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.

References