Saturn C-4

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 99,000 kg (218,000 lb) to low Earth orbit and send 32,000 kg (70,000 lb) to the Moon via trans-lunar injection. It met the initial requirements for a lunar orbit rendezvous and lunar landing mission.^[1]

Saturn C-4

Saturn C-4B on pad
Function	LEO and Lunar launch vehicle
Manufacturer	Boeing (S-IB) North American (S-II) Douglas (S-IV)
Country of origin	United States
Cost per launch	43.5 million
Cost per year	1985
Size
Height	269.0 ft (82.0 m)
Diameter	320 in (8.1 m)
Mass	1,023,670 lb (464,330 kg)
Stages	3
Capacity
Payload to LEO
Mass	218,000 lb (99,000 kg)
Payload to TLI
Mass	70,000 lb (32,000 kg)
Associated rockets
Family	Saturn
Comparable	Saturn V
Launch history
Status	Proposed (1962)
Launch sites	planned SLC 37, LC-39; Kennedy Space Center
First stage – S-IB-4
Height	113.10 ft (34.47 m)
Diameter	320 in (8.1 m)
Empty mass	149,945 lb (68,014 kg)
Gross mass	1,599,433 lb (725,491 kg)
Powered by	4 Rocketdyne F-1
Maximum thrust	6,000,000 lbf (27,000 kN)
Specific impulse	265 sec (sea level)
Burn time	139 seconds
Propellant	RP-1/LOX
Second stage – S-II-4
Height	69.80 ft (21.28 m)
Diameter	320 in (8.1 m)
Empty mass	54,978 lb (24,938 kg)
Gross mass	449,840 lb (204,040 kg)
Powered by	4 Rocketdyne J-2
Maximum thrust	800,000 lbf (3,600 kN)
Specific impulse	300 sec (sea level)
Burn time	200 seconds
Propellant	LH2 / LOX
Third stage – S-IVB
Height	61.6 ft (18.8 m)
Diameter	21.7 ft (6.6 m)
Empty mass	29,700 lb (13,500 kg)
Gross mass	271,000 lb (123,000 kg)
Powered by	1 Rocketdyne J-2
Maximum thrust	225,000 lbf (1,000 kN)
Specific impulse	421 seconds (4.13 km/s)
Burn time	165 + 335 seconds (2 burns)
Propellant	LH2 / LOX

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 30,000 kg (67,000 lb) Apollo Command/Service Module into lunar orbit, but it would not have been able to carry the 15,000 kg (32,000 lb) 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.^[2] It would have been capable of sending a 31,000 kg (68,000 lb) payload to a translunar trajectory.^[2]

See also

• Saturn C-3
• List of space launch system designs