Integrated Space Research Proposed by Orbital Civilization Studies Part I: Comprehensive Study of a Space Civilization Architecture Including a Resource-Recycling Modular Connection System for Space Habitat Construction, Simultaneous Cargo Transport, an Integrated Adaptive Closed-System Maintenance Framework, Unified Docking Standards, Autonomous Distributed Connection, Active Defense, ISRU, Ecosystem Circulation, Occupational Succession, and a Post-Currency Economy Part II: Comprehensive Study of Preparatory Requirements for Advance Migration on Earth for Life in Space Settlements, the Basic Law of Space Cities, Productivity Standards, Selective Breeding Requirements, Construction Standards, Ecosystems, Urban Planning, and Population-Function Models: Systematization of the Conditions for the Realization of Long-Term Closed Space Cities and Integrated Adaptive Survival Maintenance Systems Part III: Comprehensive Study on Interplanetary Civilization Networks: An Integrated Architecture for Deep-Space Settlement, Multi-Hop Communication, High-Precision Observation of Distant Celestial Bodies, and an Autonomous Ultra-Long-Term Exploration Continuation Infrastructure Based on Stepwise Placement of Colonial Bases Part IV: Theoretical Framework for Space Elevator Construction and Sustainable Operation: In-Atmosphere Exchange Method, Triple Spacer Slide Mechanism, and Human Safety Protocols in Dual Parallel Operation with Passenger-Cargo Separation A Four-Part Series