Although currently available booster technology could allow a major decrease in space-booster costs, hardware already built in the Saturn system has precluded any development efforts in this direction. However, as such hardware is programmed for launches during the next several years, decisions concerning such low-cost approaches become more imminent. This paper reviews the available alternatives and describes the characteristics and capabilities of a low-cost booster system which is both desirable and practically feasible for missions beginning as early as 1973.Space program plans project needs for (1) Space-Station deployment, (2) Space-Station logistics supply, (3) unmanned scientific planetary probes, (4) further lunar exploration, and (5) large synchronous-orbit satellite deployment. These missions are interrelated in the paper with regard to booster and spacecraft capabilities. It is shown that a low-cost booster based largely on current expendable booster technology can meet these interrelated requirements.In the low-cost expendable rocket technology area, three booster approaches are feasible: (1) 260-in. diam solid rockets, (2) pressure-fed liquid rockets, and (3) 156-in. diam solid rockets. This document reviews the status of these and their relative amenability to the projected requirements.