Affordable in-space transportation

iiiTABLE OF CONTENTSPage1.0 INTRODUCTION 11.1 Background and Study Objectives 11.2 Approach and Principal Findings 11.3 Study Ground Rules 22.0 MISSION MODELS 32.1 Payload Traffic Models 32.2 LEO Delivery 53.0 COST MODELS AND ASSUMPTIONS 54.0 INITIAL CONCEPT IDENTIFICATION 64.1 Concept Selection Criteria 64.2 Concept Selection Process and Results 65.0 CONCEPT SELECTION, PHASE 1, PUGH METHOD 75.1 Concept Selection Process 75.2 Concept Identification and Descriptions 75.3 Concept Selection Criteria 75.4 Concept Selection Results 96.0 CONCEPT FOCUS, PHASE 2, QUICK STUDIES 106.1 Expendable Versus Reusable Solar Thermal 106.2 Laser Electric 106.3 Chemical Propulsion 116.4 Tether 116.5 Concept Selection Results, Final Concepts for Final Study 127.0 FINAL CONCEPTS, PHASE 3 127.1 Solid Propulsion Concepts 157.2 Hybrid Propulsion Concepts 177.3 Cryogen Propulsion Concepts 197.4 Solar Electric Propulsion Concepts 217.5 Solar Thermal Propulsion Concepts 247.6 Nuclear Thermal Propulsion Concepts 278.0 STUDY RESULTS AND SENSITIVITIES 308.1 Results of Cost Analyses 318.2 Sensitivity Results 34