Silverstein Committee
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The Saturn Vehicle Evaluation Committee (better known as the Silverstein Committee) was a US government commission, assembled in 1959 to recommend specific directions that NASA could take with the Saturn program. The committee was chaired by Abe Silverstein. The committee recommended the development of new, hydrogen-burning upper stages for the Saturn, and outlined eight different configurations for heavy-lift boosters ranging from very low-risk solutions making heavy use of existing technology, to designs that relied on hardware that had not been developed yet, including the proposed new upper stage.
The committee established two criteria for a successful Saturn program: fast development time of an initial system, and growth potential for future launches. The group listed three missions for the initial Saturn vehicle: unmanned lunar and deep space missions with an escape payload of about 4,500 kilograms; 2,250-kilogram payloads for a 24-hour equatorial orbit; and manned spacecraft missions in low orbits, such as Dyna Soar.
To make such "high altitude" missions practical, the performance of the upper stages would be key. Every pound used in the stage or its fuel would mean that much less cargo, given any particular booster. Since it was the power-to-weight ratio that they needed, upper stages based on liquid hydrogen seemed to be the only way forward -- the light weight of the fuel makes up for any difficulty handling it. At the time no liquid hydrogen fueled engines were in use, and the ones being proposed were much larger than anything built so far. A larger, conventionally fueled second stage - 5.59-meter diameter - met mission requirements, but time and cost seemed excessive for a rocket stage with little growth potential. In defense of this risky position the committee noted: "If these propellants are to be accepted for the difficult top-stage applications, there seems to be no valid engineering reasons for not accepting the use of high-energy propellants for the less difficult application to intermediate stages."
For lower stages the designers has somewhat more flexibility. Since the booster isn't lifting itself, the overall payload can be increased simply by making it larger. Existing NASA boosters were all based on various ICBM platforms such as Titan, but the committee rejected all of these as having little growth potential. New boosters were required, and the committee suggested building a smaller one made up of clustered Thor missiles to test the new upper stages while a new and much larger lower stage was developed. Payloads of various sizes and missions could be handled by mixing and matching various components. They felt this would also allow the new upper stages to be thoughougly tested before being tasked with a lunar mission: "vehicle reliability will be emphasized... through a continued use of each development stage in later vehicle configurations."
The Saturn C-1 would consist of a clustered booster, a new Douglas Aircraft second stage with four hydrogen burning Centaur engines of 15-20,000 lbf thrust (66,720 - 88,960 newtons) per engine, and a modified Centaur as a third stage. The C-1 would become the C-2 upon insertion of a new oxygen-hydrogen second stage with two 150-200,000 lbf thrust (667,200 to 889,600 newton) engines. The top two stages of the Saturn C-1 would then become stages three and four on the C-2 version. The committee proposed to launch ten C-1s starting in the fall of 1961.
On the last day of 1959, Glennan approved the Silverstein recommendations. Chances of meeting the schedule improved with two Eisenhower administration decisions in January 1960. The Saturn project received a DX rating, which designated a program of highest national priority, which gave program managers privileged status in securing scarce materials. More important, the administration agreed to NASA's request for additional funds. The Saturn FY 1961 budget was increased from $140 million to $230 million. On 15 March 1960 President Eisenhower officially announced the transfer of the Army's Development Operations Division to NASA.
[edit] Notes
Until 1963 Saturns were classified by a C and an Arabic numeral. People generally assume that C stood for configuration; but according to Kennedy Space Center's Spaceport News (17 Jan. 1963), MSFC engineers used it to designate vehicular "concepts." Saturn C-1 denoted the concept of the S-1 booster topped with upper stages using liquid hydrogen as a propellant. C-2, C-3, and C-4 were drawing- board concepts that preceded the C-5 (Saturn V) moon rocket. For additional information on the origins of Saturn, see John L, Sloop, Liquid Hydrogen as a Propulsion Fuel, 1945-1959, NASA SP-4404, in press, chap. 12.
[edit] References
23. Report on Saturn, pp. 4, 7, 8, and table III. 24. Emme, "Historical Perspectives," p. 18; Robert L. Rosholt, An Administrative His
