posted on Dec, 15 2007 @ 02:03 AM
Sponsoring/Monitoring Agency: National Aeronautics and Space Administration Washington D.C.
Author: Lee S. Mason, Carlos D. Rodriguez, Barbara I. McKissock, James C. Hanlon, Brian C. Mansfield
This study examines the potential for integrating Brayton-cycle power conversion with the SP-100 reactor for lunar surface power system applications.
Two designs were characterized and modeled.
The first design integrates a 100-kWe SP-100 Brayton power system with a lunar lander. This system is intended to meet early lunar mission power needs
while minimizing on-site installation requirements. Man-rated radiation protection is provided by an integral multilayer, cylindrical ithium
hydride/tungsten (LiH/W) shield encircling the reactor vessel.
Design emphasis is on ease of deployment, safety, and reliability while utilizing relatively near-term technology. The second design combines Brayton
conversion with the SP-100 reactor in an erectable 550-kWe power plant concept intended to satisfy later-phase lunar base power requirements. This
system capitalizes on experience gained from operating the initial 100-kWe module and incorporates some technology improvements. For this system the
reactor is emplaced in a lunar regolith excavation to provide man-rated shielding, and the Brayton engines and radiators are mounted on the lunar
surface and extend radially from the central reactor. Design emphasis is on performance, safety, long life, and operational flexibility.
Design emphasis is on performance, safety, long life, and operational flexibility.
Recent studies examining approaches for lunar base missions have suggested a need for
nuclear reactor power systems (Synthesis Group Report, 1991). Most mission development strategies suggest a phased approach for meeting mission
objectives. Power requirements for permanent-occupancy lunar surface missions range from tens of kilowatts for the early emplacement phases to
hundreds of kilowatts for the later operational phases. Nuclear reactor power systems provide a low-mass, long-life option for meeting these
requirements. One strategy for satisfying lunar base power requirements is through a centralized utility. Power could be generated by multiple systems
and provided to a central user-common switching station. From the switching station electric power would be distributed to the various users.
The stated power requirements are commensurate with results from NASA's 90-day study of the Moon and Mars. Within the power generation area an
initial nuclear reactor system could be emplaced that would have the capacity to meet near-term power requirements associated with the emplacement
Principal power users for this phase of the mission might include initial crew habitat modules, science platforms, rover recharging facilities, and
in-situ resource utilization (ISRU) demonstrations.
A photovoltaic and regenerative fuel cell (PV/RFC) system might also be utilized to provide redundant power to the habitat life support systems.
If the lunar base grows and power requirements increase to accommodate laboratory modules, constructible habitats, liquid oxygen plants, launch and
landing servicing facilities, and expanded science, a subsequent larger nuclear reactor system could be delivered to complement and eventually replace
the original system.