Saturn INT-19

North American study, 1966. Saturn variant with 4 to 12 Minuteman motors as boosters, Saturn II stage as core, and Saturn IVB upper stage. Saturn II stage would be fitted with lower expansion ratio engines and would ignite at sea level. Various combinations of numbers of strap-ons, propellant loading of the two core stages were studied.

Liftoff Mass - kg	MM Motors at Liftoff	MM Motors 2nd Round	MM Motors 3rd Round	S-II Propellant - kg	S-IVB Propellant - kg	Payload - kg
328,300	-	-	-	188,200	77,100	5,500
463,500	2	2	-	217,700	80,300	13,200
579,600	4	2	-	277,600	76,600	20,100
579,600	4	4	-	236,700	73,000	18,100
722,900	6	2	-	367,800	76,600	27,200
722,900	6	4	-	318,400	78,000	26,800
734,200	6	4	2	294,800	81,200	23,100
722,900	6	6	-	273,900	78,900	25,400
866,700	8	4	-	410,900	80,700	28,800
866,700	8	4	-	410,900	75,700	33,700
866,700	8	4	-	410,900	75,200	34,200

LEO Payload: 34,320 kg (75,660 lb) to a 185 km orbit at 28.00 degrees.

Stage Data - Saturn INT-19

• Stage 0. 12 x Minuteman-1. Gross Mass: 23,077 kg (50,876 lb). Empty Mass: 2,292 kg (5,052 lb). Thrust (vac): 791.300 kN (177,891 lbf). Isp: 262 sec. Burn time: 60 sec. Isp(sl): 237 sec. Diameter: 1.67 m (5.47 ft). Span: 1.67 m (5.47 ft). Length: 7.49 m (24.57 ft). Propellants: Solid. No Engines: 1. Engine: M55/TX-55/Tu-122. Status: Out of Production. Comments: First stage of Minuteman I. Proposed as zero stage for various Saturn variants in 1960's. Surplus motors used in ABM SDI tests in 1980's and 1990's.

• Stage 1. 1 x Saturn II-SL. Gross Mass: 490,952 kg (1,082,363 lb). Empty Mass: 44,240 kg (97,530 lb). Thrust (vac): 5,500.765 kN (1,236,621 lbf). Isp: 390 sec. Burn time: 310 sec. Isp(sl): 275 sec. Diameter: 10.06 m (33.00 ft). Span: 10.06 m (33.00 ft). Length: 24.84 m (81.49 ft). Propellants: Lox/LH2. No Engines: 5. Engine: J-2-SL. Status: Study 1966. Comments: Saturn II modified with reduced expansion ratio J-2 engines for use a first stage (sea level launch). Requires solid rocket motor augmentation to get off the ground.

• Stage 2. 1 x Saturn IVB (S-IB). Gross Mass: 118,800 kg (261,900 lb). Empty Mass: 12,900 kg (28,400 lb). Thrust (vac): 1,031.600 kN (231,913 lbf). Isp: 421 sec. Burn time: 475 sec. Isp(sl): 200 sec. Diameter: 6.61 m (21.68 ft). Span: 6.61 m (21.68 ft). Length: 17.80 m (58.30 ft). Propellants: Lox/LH2. No Engines: 1. Engine: J-2. Status: Out of Production. Comments: Saturn IB version of S-IVB stage. Due to lower payload, 300 kg saving in structure compared to Saturn V version. Due to deletion of restart requirement, 700 kg saving in propulsion system (primarily reduction in helium for restart).