The 1990\u27s and Space Station Freedom are the next critical, steps in our space endeavors which will be stepping stones for the new century permanent exploration of the moon and the solar system. Freedom Station and transportation requirements for the lunar outpost are partitioned into three phases - the emplacement phase, the consolidation phase, and the utilization phase. The Earth-to-orbit transportation system must ferry vehicles, cargo, crew, and propellant to low Earth orbit (LEO) to support these lunar outpost phase requirements. The lunar transportation system is designed to move crew, science instruments, and support equipment from LEO to the surface of the moon. The lunar transportation system consists of the lunar transfer vehicle (LTV) and the lunar excursion vehicle (LEV). These reusable and highly reliable vehicles provide multiple mission utility through common vehicle usage for cargo and crew delivery. Mission analyses and the lunar payload model have established vehicle design and sizing requirements. A 300-km circular orbit is assumed for the low lunar orbit (LLO) staging point for the lunar surface base. Freedom is used as the LEO transportation node. The LEV is sized to deliver 15t to the lunar surface for the first piloted flight. The LEV can deliver 33t to the lunar surface in the cargo expendable mode. Different transportation system options are designed and sized to compare and show sensitivity of the initial mass required in LEO to determine the most effective and efficient transportation concept
