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   Saturn V-B
   Studied in 1968 by Marshall Space Flight Center, the Saturn V-B was considered an interesting vehicle concept because it nearly represents a single-stage to orbit booster, but is actually a stage and a half booster just like the Atlas. The booster would achieve liftoff via five regular F-1 engines;...
   Found op http://en.wikipedia.org/wiki/Saturn_V-B
   
   

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