This paper summarizes recent work performed by The Boeing Company to evaluate various low-cost methods of providing rocket-launch vehicles of payload capability between the uprated Saturn I (40,000 lb. to low earth orbit) and Saturn V (262,000 lb. to low earth orbit). A NASA space program has been postulated indicating that from 33 to 69 vehicles may be required during the 1970's in the payload range described.In increasing development complexity, the vehicles evaluated include 1) existing developed equipment like the S-IC and S-IVB stages of Saturn V, 2) a new 260-inch diameter solid booster vehicle and 3) new pressure fed storable propellant booster vehicles.Comparisons are made evaluating the effort and cost required to implement the various systems and their individual operational costs. The low cost system selection changes with mission requirements and is further contingent on a booster stage recovery and reuse decision.