Nomenclature

The overall objective of this study is the thermodynamically consistent quantification of second law and performance losses for vehicle configurations implemented or suggested for access-to-space missions and the development of the relationships between the mission entropy generation and overall mission performance. A full vehicle trajectory code utilizing simplified models for multi-stage rockets and air-breathing propulsion systems is developed and validated specifically for use as a testbed for second law-based theory and concepts. Results are shown in which a multi-stage rocket-powered vehicle and a rocket/air-breathing (combined cycle) vehicle are compared in detail, both in terms of conventional information as well as loss and energy utilization analysis incorporating the second law of thermodynamics. The analysis code is highly modular and improvements can and will be incorporated in terms of aerodynamics, propulsion, and sub-systems weights modeling