S-IV

Summary

The S-IV was the second stage of the Saturn I rocket used by NASA for early flights in the Apollo program.

S-IV
Schematics of the S-IV
ManufacturerDouglas Aircraft Company
Country of originUnited States
Used onSaturn I (stage 2)
General characteristics
Height12.19 m (40.0 ft)
Diameter5.49 m (18.0 ft)
Gross mass50,576 kg (111,501 lb)
Propellant mass45,359 kg (100,000 lb)
Empty mass5,217 kg (11,500 lb)
Launch history
StatusRetired
Total launches6
Successes
(stage only)
6
Failed0
First flightJanuary 29, 1964
Last flightJuly 30, 1965
S-IV 100 series
Powered by6 RL-10 engines
Maximum thrust400 kN (90,000 lbf)
Specific impulse410 s (4.0 km/s)
Burn time482 s
PropellantLH2 / LOX

The S-IV was manufactured by the Douglas Aircraft Company and later modified by them to the S-IVB, a similar but distinct stage used on the Saturn IB and Saturn V rockets.[1]

The S-IV stage was a large LOX/LH2-fueled rocket stage used for the early test flights of the Saturn I rocket. It formed the second stage of the Saturn I and was powered by a cluster of six RL-10A-3 engines. Each one of the engines supplied 66.7 kilonewtons (15,000 lbf) of thrust for a total of about 400 kilonewtons (90,000 lbf). The cryogenic LH2 (liquid hydrogen) and LOX (liquid oxygen) tanks were separated by a common bulkhead. The forward bulkhead of the LOX tank formed the aft bulkhead of the LH2 tank. This saved up to 20% of structural weight.[2][3]

Flight history

edit
Mission serial number Launch date

(UTC)

Launch notes
SA-1 October 27, 1961

15:06:04

 

First test flight. Block I. Suborbital. Range: 398 km. Apogee: 136.5 km. Apogee Mass: 115,700 lb (52,500 kg). Dummy S-IV and S-V stages.

SA-2 April 25, 1962

14:00:34

 

Second test flight. Block I. Suborbital. 86,000 kg water released at apogee of 145 km as part of Project Highwater. Dummy S-IV and S-V stages.

SA-3 November 16, 1962

17:45:02

 

Third test flight. Block I. Suborbital. 86,000 kg water released at apogee of 167 km. Dummy S-IV and S-V stages. Second and last Project Highwater flight.

SA-4 March 28, 1963

20:11:55

 

Fourth test flight. Block I. Suborbital. Dummy S-IV second stage and S-V third stage. Apogee: 129 km. Range: 400 km.

SA-5 January 29, 1964

16:25:01

 

First live S-IV second stage. First Block II. First to orbit: 760 x 264 km. Mass: 38,700 lb (17,550 kg). Decayed 30 April 1966.

SA-6 May 28, 1964

17:07:00

First Apollo boilerplate CSM launch. Block II. Orbit: 204 x 179 km. Mass: 38,900 lb (17,650 kg). Apollo BP-13 decayed 1 June 1964.
SA-7 September 18, 1964

16:22:43

 

Second Apollo boilerplate CSM launch. Block II. Orbit: 203 x 178 km. Mass: 36,800 lb (16,700 kg). Apollo BP-15 decayed 22 September 1964.

SA-9 February 16, 1965

14:37:03

 

Third Apollo boilerplate CSM. First Pegasus micrometeoroid satellite. Orbit: 523 x 430 km. Mass: 3,200 lb (1,450 kg). Pegasus 1 decayed 17 September 1978. Apollo BP-26 decayed 10 July 1985.

SA-8 May 25, 1965

07:35:01

Fourth Apollo boilerplate CSM. Only night launch. Second Pegasus micrometeoroid satellite. Orbit: 594 x 467 km. Mass: 3,200 lb (1,450 kg). Pegasus 2 decayed 3 November 1979. Apollo BP-16 decayed 8 July 1989.
SA-10 July 30, 1965

13:00:00

Third Pegasus micrometeoroid satellite. Orbit: 567 x 535 km. Mass: 3,200 lb (1,450 kg). Pegasus 3 decayed 4 August 1969. Apollo BP-9A decayed 22 November 1975.

References

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  • Bilstein, Roger E. (1999). "6". Stages to Saturn: A Technological History of the Apollo/Saturn Launch. DIANE Publishing. ISBN 9780788181863. Retrieved 2010-05-04.
  • NASA (April 1975). "Apollo Program Summary Report (Large file)" (PDF).