Saturn C-5N

The Saturn C-5N was a conceptual successor to the Saturn V launch vehicle which would have had a nuclear thermal third stage instead of the S-IVB used on the Saturn V. This one change would have increased the payload of the standard Saturn V to Low Earth orbit from 118,000 kg to 155,000 kg.

Saturn C-5N

Country of origin	United States
Size
Height	98 m (320 ft)
Diameter	10 m (33 ft)
Mass	2,841,040 kg (6,263,420 lb)
Stages	3
Capacity
Payload to LEO
Altitude	115 mi (185 km)
Mass	155,000 kilograms (342,000 lb)
Payload to TLI
Mass	64,000 kg (141,000 lb)
Associated rockets
Family	Saturn
Launch history
Status	Concept
Partial failure(s)
First stage – S-IC C-5A
Height	42.87 m (140.64 ft)
Diameter	10 m (33 ft)
Empty mass	131,495 kg (289,896 lb)
Gross mass	2,217,285 kg (4,888,276 lb)
Powered by	5 × F-1
Maximum thrust	38,257.99 kN (8,600,738 lbf) vacuum
Specific impulse	304 s (2.98 km/s)
Burn time	160 seconds
Propellant	LOX / RP-1
Second stage – S-II C-5A
Height	21.39 m (70.17 ft)
Diameter	10 m (33 ft)
Empty mass	31,740 kg (69,970 lb)
Gross mass	384,100 kg (846,700 lb)
Powered by	5 × J-2
Maximum thrust	4,446.65 kN (999,646 lbf) vacuum
Specific impulse	420 s (4.1 km/s)
Burn time	320 seconds
Propellant	LOX / LH2
Third stage – S-N C-5N
Height	19.29 m (63.30 ft)
Diameter	10.26 m (33 ft 8 in)
Empty mass	10,429 kg (22,992 lb)
Gross mass	53,694 kg (118,375 lb)
Powered by	1 × NERVA
Maximum thrust	266.80 kN (59,979 lbf) vacuum
Specific impulse	800 s (7.8 km/s)
Burn time	1250 seconds
Propellant	Nuclear / LH2

The conceptual Saturn C-5N was designed as an evolutionary successor to the Saturn V, intended for the planned crewed mission to Mars by 1980, it would have cut crewed transit times to Mars to about 4 months,^[1] instead of the 8–9 months of chemical rocket engines. However the Mars mission, along with all work related to the evolutionary successors of the Saturn V, was cancelled in 1972-3 by the Nixon Administration.^[2][3]

The ground testing of the NERVA nuclear thermal rocket engines intended for the Saturn C-5N's,^[4] in-space 3rd stage, still hold a number of combined rocket thrust and specific impulse records. The concept of nuclear thermal rockets serving as the in-space rocket stage influenced the 1990s Project Timberwind.

See also

• NERVA