Boeing study, 1967-1968. Use of full length 260 inch solid rocket boosters with stretched Saturn IC stages presented problems, since the top of the motors came about half way up the liquid oxygen tank of the stage, making transmission of loads from the motors to the core vehicle complex and adding a great deal of weight to the S-IC. Boeing's solution was to retain the standard length Saturn IC, with the 260 inch motors ending half way up the S-IC/S-II interstage, but to provide additional propellant for the S-IC by putting propellant tanks above the 260 inch boosters. These would be drained first and jettisoned with the boosters. This added to the plumbing complexity but solved the loads problem.

LEO Payload: 362,700 kg. to: 185 km Orbit. at: 28.0 degrees. Liftoff Thrust: 16,505,060 kgf. Total Mass: 10,351,050 kg. Core Diameter: 10.1 m. Total Length: 86.0 m. Flyaway Unit Cost $: 446.60 million. in 1985 unit dollars.

• Stage Number: 0. 4 x 260 inch solid FL Gross Mass: 1,648,355 kg. Empty Mass: 156,126 kg. Thrust (vac): 3,608,918 kgf. Isp: 263 sec. Burn time: 114 sec. Isp(sl): 238 sec. Diameter: 6.6 m. Span: 6.6 m. Length: 30.5 m. Propellants: Solid No Engines: 1. AJ-260X

• Stage Number: 1. 1 x Saturn MS-IC/260 Gross Mass: 2,721,600 kg. Empty Mass: 181,400 kg. Thrust (vac): 3,948,100 kgf. Isp: 304 sec. Burn time: 192 sec. Isp(sl): 265 sec. Diameter: 10.1 m. Span: 19.0 m. Length: 42.0 m. Propellants: Lox/Kerosene No Engines: 5. F-1

• Stage Number: 2. 1 x Saturn MS-II-2 Gross Mass: 600,788 kg. Empty Mass: 59,844 kg. Thrust (vac): 714,156 kgf. Isp: 451 sec. Burn time: 324 sec. Isp(sl): 280 sec. Diameter: 10.1 m. Span: 10.1 m. Length: 29.6 m. Propellants: Lox/LH2 No Engines: 5. HG-3

• 228 - Lowther, Scott, Saturn: Development, Details, Derivatives and Descendants, Work in progress. Availabe chapters may be ordered directly from Scott Lowther at web site indicated. HTML when accessed: http://www.webcreations.com/ptm