Unlike gas turbine power systems which consume chemical or nuclear energy, the energy consumption and/or cycle efficiency should not be a suitable criterion for evaluating the performance of space solar Brayton cycle power. A new design goal, life cycle cost, can combine all the power system characteristics, such as mass, area, and station-keeping propellant, into a unified criterion. Effects of pressure ratio, recuperator effectiveness, and compressor inlet temperature on life cycle cost were examined. This method would aid in making design choices for a space power system.

The characteristics of a Closed Brayton Cycle at maximum power point is analyzed. The results are compared with the Curzon and Ahlborn efficiency. For endoreversible cycles, the CBC efficiency at maximum power point is the same as that of Curzon and Ahlborn. Dependences of maximum power are also analyzed in respect to temperature ratio and component losses.

The paper describes a computer program to simulate space solar closed Brayton cycle (CBC) power systems. The program has been written for IBM-compatible microcomputers. Either analytical equations or performance characteristics of individual components are used to model the steady-state operation of the power system. The results obtained by calculation have been compared with ground test data.