EXECUTIVE SUMMARY; INTRODUCTION AND BACKGROUND; NAVAL COMMUNICATIONS REQUIREMENTS; CURRENT AND PROGRAMMED SATELLITE COMMUNICATIONS CAPABILITIES; GOAL ARCHITECTURE-NAVSATCOM-21; NAVY OPERATIONAL CAPABILITIES ENABLED; A COMPARISON OF NAVSATCOM-21 WITH CURRENT NAVY COMMUNICATIONS ARCHITECTURE; GENERAL FINDINGS AND OVERALL RECOMMENDATIONS; Appendix: LIST OF ACRONYMS AND ABBREVIATIONS