The present ESAS architecture for lunar exploration is dependent on a large launcher. It has been assumed that either the ARES V or something similar, such as the proposed Jupiter âoeDirectâ lifters are mandatory for serious lunar exploration. These launch vehicles require extensive development with costs ranging into the tens of billions of dollars and with first flight likely most of a decade away. In the end they will mimic the Saturn V programmatically: a single-purpose lifter with a single user who must bear all costs. This programmatic structure has not been shown to be effective in the long term. It is characterized by low demonstrated reliability, ballooning costs and a glacial pace of improvements.

The use of smaller, commercial launchers coupled with orbital depots eliminates the need for a large launch vehicle. Much is made of the need for more launches- this is perceived as a detriment. However since 75% of all the mass lifted to low earth orbit is merely propellant with no intrinsic value it represents the optimal cargo for low-cost, strictly commercial launch operations. These commercial launch vehicles, lifting a simple payload to a repeatable location, can be operated on regular, predictable schedules. Relieved of the burden of hauling propellants, the mass of the Altair and Orion vehicles for a lunar mission is very small and can also be easily carried on existing launch vehicles. This strategy leads to high infrastructure utilization, economic production rates, high demonstrated reliability and the lowest possible costs.

This architecture encourages the exploration of the moon to be conducted not in single, disconnected missions, but in a continuous process which builds orbital and surface resources year by year. The architecture and vehicles themselves are directly applicable to Near Earth Object and Mars exploration and the establishment of a functioning depot at earth-moon L2 provides a gateway for future high-mass spacecraft venturing to the rest of the solar system.