b fe le, 1 . f t Ke then becane a "first choice for the operation." It notes that if there is a longer time scale for the series, several other desirable features can probably be incorporated in the warhead carrier such as self-propelled pods and rockets mounted on the carrier to improve positioning accuracy of the scientific experinents. ~~ "The decision was made to attempt to satisfy the experimental objectives with vehicles available "on the shelf!' and to avoid any vehicle modifications which would lead to AEC requirements for proof test to satisfy reliability and safety criteria. The vehicles selected meet these objectives. In addition to the warhead delivery capability it was felt necessary to provide additional capacity for secondary pay loads. All of the large boosters considered: Thor, Redstone and Polaris, have Escess capability in the lower altitude. If external ejection of secondary payloads could be accomplished the modifications to a payload carrier section would be held to a minimum. The Thor has this external capability while the Polaris does not without extensive engineering. At low altitudes the Thor is not fully utilized. The consideration of a single system providing operational expediency overcane the objection of wasting vehicle performance. Thor trajectories were exceptionally adaptable to ‘the warhead positioning considerations.” Note that the Air Force looked at the Blue Scout first stage with an fero-jet senior engine, the Tner, and in somewhat less detail the Redstone and the Polaris. The Blue Scout would have required additional stages for anything above 50 kilometers and adapting to the proposed warhead and possible external pods would require additional development. The Redstone it is noted, doean't have the altitude capability above 400 kilometers and extensive modification would have to bteaccomplished on the warhead fusing system. The Polaris while it can meet all the altitude requirements will not accept easily all of tne warheads and has no provisionsfor attaching external instrumentation packages. Even in this report, the operational flexibility of the Polaris is noted as being’éxtrenmely desirable feature. As for the Thor, it is stated "The Thor booster is available from current inventories, can accomplish ali altitude requirements, requires only minor rodirication for adaptation to the proposed warheads, and has an established high degree of reliability. Twenty-three out of twenty-five Thor space boosters launched since 4 Oct 1960 have been successful. The over-all space booster success is 55 52 launches. The Thor also has provisions for installation of external ejectable scientific instrumentation packages." The engine cut off capability of the Thor and the separability of the booster from the vicinity of the warhead is noted as an advantage. As for aerospace ground equipment (AGE) it is noted that the Redstone and Thor have similar requirements as well as sinilar launch pad requirements. The Polaris is designed for tube-type launch which would require entirely different operational planning and presumably the Navy would make the Observation Island available if the Polaris were selected. Blue Scout facilities and AGE are far lesser requirements than those of the other three vehicles. Further, it is noted "Although it may be somewnat cheaper to use Blue Scout vehicles from a cost standpoint it is more desirable to utilize a more expensive vehicle which gives greater assurance of successful mission accomplishment." In the summary of Vehicle Selection it states “The experimental objectives of this proposal can be met through utilization

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