Spacecraft Operations

The book describes the basic concepts of spaceflight operations, for both, human and unmanned missions. The basic subsystems of a space vehicle are explained in dedicated chapters, the relationship of spacecraft design and the very unique space environment are laid out. Flight dynamics are taught as well as ground segment requirements. Mission operations are divided into preparation including management aspects, execution and planning. Deep space missions and space robotic operations are included as special cases. The book is based on a course held at the German Space Operation Center (GSOC). Foreword 6 Preface 8 List of Editors and Contributors 10 Abbreviations 16 Contents 28 Chapter 1: Overview Space Segment 32 1.1 The Space Environment 32 1.1.1 Introduction 32 1.1.2 Launch Vehicle 33 1.1.2.1 Acoustic/Vibration levels 33 1.1.2.2 Static Acceleration 34 1.1.2.3 Mechanical Shock 34 1.1.3 Spacecraft Operational Environment 35 1.1.3.1 Vacuum 35 1.1.3.2 Solar Radiation Flux 36 1.1.3.3 Particle Radiation 37 1.1.3.4 Radiation Belts 38 1.1.3.5 Atmosphere 39 1.1.3.6 Debris 41 1.1.3.7 Gravity and Magnetic Fields 43 1.2 Space Systems Engineering 44 1.2.1 Definition of System Engineering 44 1.2.2 Objectives and Requirements 46 1.2.3 Design Drivers and Trade-offs 49 1.2.4 Concurrent Engineering 52 1.3 Fundamentals of Space Communications 52 1.3.1 Introduction 52 1.3.2 Baseband 53 1.3.2.1 Source Coding 53 1.3.2.2 Channel Coding 54 1.3.2.3 Baseband Shaping 57 1.3.2.4 Modulation 58 1.3.3 Carrier 61 1.3.3.1 Elements of a Space Link 61 Power Amplifier 61 Antenna 61 Noise 62 Receiver 63 1.3.3.2 Link Budget Equation 63 References 65 References to Sect. 1.1 65 References to Sect. 1.2 65 Chapter 2: Mission Operations 66 2.1 Mission Operations Preparation 66 2.1.1 Introduction with Examples 67 2.1.2 Driving Factors 69 2.1.2.1 Requirements 69 2.1.2.2 Cost/Funding 71 2.1.2.3 Technology/Complexity 71 2.1.2.4 Schedule 72 2.1.2.5 Experience 73 2.1.2.6 Risk (Also Regarding Launch Delays) 73 2.1.3 Personnel, Roles, and Responsibilities 73 2.1.3.1 Project Manager 74 2.1.3.2 Mission Director 74 2.1.3.3 Flight Director 75 2.1.3.4 System Engineer 75 2.1.3.5 Simulation Officer 75 2.1.3.6 Quality Assurance Engineer 75 2.1.3.7 Subsystem Engineer 76 2.1.3.8 Project Office/Project Officer 76 2.1.3.9 Controlling 76 2.1.3.10 Configuration Manager 76 2.1.3.11 Security Officer 77 2.1.4 Required Data, Products, and Tools 77 2.1.4.1 Test Data and Data Generators 77 2.1.4.2 Spacecraft Simulator 77 2.1.4.3 Mission Information Base 78 2.1.4.4 MandC System Software 78 2.1.4.5 Ground and Flight Procedures for Nominal and Contingency Situations 78 2.1.4.6 Operations Support Tools 79 2.1.4.7 Project Documentation, E.g., Spacecraft User Manual, Ground Segment Design Description, Operational Documentation 79 2.1.5 Activities, Tasks, and Schedule 79 2.1.6 Review Process 81 2.2 Mission Operations Execution 85 2.2.1 Various Phases During Execution 85 2.2.1.1 General Description of the Execution Phase 86 2.2.1.2 Launch and Early Orbit Phase 87 2.2.1.3 Commissioning Phase 88 2.2.1.4 Routine Phase 90 2.2.1.5 End of Mission or Disposal Phase 91 2.2.2 Staffing of the Flight Control Team 91 2.2.2.1 Mission Operations Team Lead 92 2.2.2.2 Subsystem Specialists 93 2.2.2.3 Command Operator 93 2.2.2.4 Planner 93 2.2.2.5 Flight Dynamics 94 2.2.2.6 Ground Data Systems 94 2.2.2.7 Assistance Team 94 2.2.3 Interactions within the Flight Control Team and Flight Procedures 95 2.2.3.1 Interactions within the Flight Control Team 95 2.2.3.2 Flight Operations Procedures 95 Definition and Applications 96 FOP Life Cycle 97 2.2.3.3 Anomalies and Recommendations 98 Anomalies 98 Recommendations 98 2.2.4 The Mission Type Defines the Operational Concept 99 2.2.4.1 Low Earth Orbit: GRACE 99 2.2.4.2 Geostationary Earth Orbit: SATCOMBw 101 2.2.4.3 Deep Space Missions: GALILEO 104 2.2.5 Summary 105 2.3 Flight Experience 106 2.3.1 Statistics 106 2.3.2 Interpretation of Telemetry 108 2.3.3 Failure Probability Vs. Operational Experience 111 2.3.4 Contingency Handling 112 2.3.5 Mission Example TV-SAT 1 115 2.3.5.1 Failure Analysis 115 2.3.5.2 Recovery Attempts 118 2.3.5.3 Final Actions 119 References 120 References to Sect. 2.1 120 References to Sect. 2.2 120 Chapter 3: Communication and Infrastructure 121 3.1 Control Center Design 121 3.1.1 Infrastructure 123 3.1.1.1 Control Rooms 124 3.1.1.2 Public Space in the Control Center 125 3.1.1.3 Server Rooms and Computer Hardware 126 3.1.2 Control Center Network 127 3.1.2.1 Network Topologies 127 3.1.2.2 Network Technologies 128 3.1.3 Control Center Software 130 3.1.3.1 General 130 3.1.3.2 Space Link Extension Gateway System 132 3.1.3.3 Automated File Distribution Subsystem 133 3.1.3.4 Spacecraft Monitoring and Control System 133 3.1.4 Outlook 136 3.2 Ground Station Network 136 3.2.1 Station Selection 137 3.2.2 Station Communication 141 3.2.2.1 Communication Paths 141 3.2.2.2 Data Transfer Methods 142 3.2.2.3 GSN Examples 143 3.2.3 LEOP and Routine Operations 145 3.2.3.1 GDS Engineering Team (NOPE) 146 3.2.3.2 Systems (Network and Systems Control) 146 3.2.3.3 ``Systems ́ ́ (Network and Systems Control Team) 147 3.2.3.4 Scheduling Office 147 Chapter 4: Flight Dynamic Operations 149 4.1 Orbital Dynamics 149 4.1.1 Introduction 149 4.1.2 Theoretical Aspects 150 4.1.2.1 Description of a Satellite Orbit 150 Geometry 150 Orientation in Space 151 4.1.2.2 Satellite Velocity 152 Elliptic Orbit 153 Circular Orbit 153 First Cosmic Velocity 153 Second Cosmic Velocity 154 4.1.2.3 Orbital Period 154 4.1.2.4 Orbit Perturbations 154 Earth Gravitational Field 155 Air Drag 156 4.1.2.5 Maneuvers 157 In-Plane Maneuver 158 Out-of-Plane Maneuver 159 Combined Maneuvers 160 4.1.2.6 Orbit Maintenance 161 4.1.3 Flight Dynamics Tasks 163 4.1.3.1 Mission Preparation 163 Orbit Selection and Ground Station Visibility Analysis 163 Launch Window 164 First Acquisition Analysis 166 Implementation of an Operational Flight Dynamics System 167 4.1.3.2 Mission Execution 167 Orbit Determination and Prediction 168 Maneuver Planning 169 Collision Avoidance Operations 172 4.2 Attitude Dynamics 174 4.2.1 Introduction 174 4.2.2 Disturbances 177 4.2.2.1 Satellite Intrinsic 177 4.2.2.2 External Influences 177 4.2.3 Attitude Determination 178 4.2.4 Attitude Propagation 183 4.2.5 Attitude Control 185 4.2.6 Tasks of AOCS (Attitude and Orbit Control System) 189 4.2.6.1 Example 1 190 4.2.6.2 Example 2 192 References 195 References to Sect. 4.1 195 References to Sect. 4.2 195 Chapter 5: Mission Planning 197 5.1 The Planning Problem 197 5.1.1 Introduction 197 5.1.2 General Overview of a Mission Planning System 198 5.1.3 Techniques for Timeline Generation 201 5.1.3.1 General Considerations 201 5.1.3.2 GSOC Modeling Language 203 Timeline Entry 203 Task 203 Minimum and Maximum Duration of a Task 203 Time Dependency with Other Task 204 Timeline 204 Groups 204 Resources 205 5.1.3.3 Application Examples of the Modeling Language 208 Opportunities, e.g., Ground Station Visibilities 208 Equipment Resources, e.g., Downlink Antennas of a Certain Ground Station 208 Renewable Resources, e.g., Battery Discharge Level 209 Gliding Windows (in Between Equipment and Renewable Resource) 211 Combining Resource Types 211 5.1.3.4 Scheduling Algorithms 213 Fixed Plan 213 Repeated Rescheduling and Incremental Scheduling 214 5.1.4 Summary 215 5.2 Mission Planning for Unmanned Systems 215 5.2.1 Introduction 215 5.2.2 Mission Planning System Example 216 5.2.3 Considerations on Designing a Mission Planning System 218 5.2.4 Mission Planning at Various Time Scales 219 5.2.5 Conclusions and Outlook 220 5.3 Mission Planning for Human Spaceflight Missions 222 5.3.1 Introduction 222 5.3.2 Basic Considerations 225 5.3.3 Planning Teams 226 5.3.4 Concept of Crew Flexibility 227 5.3.5 Planning Phases Overview 228 5.3.6 Planning Products and Processes 229 5.3.6.1 Strategic Planning 229 5.3.6.2 Tactical Planning 231 5.3.6.3 Pre-Increment Planning 233 5.3.6.4 Increment Planning 235 5.3.6.5 Real-Time Planning 237 5.3.7 Planning Tools 239 5.3.8 Conclusion 240 References 240 References to Sect. 5.1 240 References to Sect. 5.2 241 References to Sect. 5.3 241 Chapter 6: Spacecraft Subsystem Operations 242 6.1 Telemetry, Commanding and Ranging Subsystem 242 6.1.1 Definition of Subsystem 242 6.1.2 Signal Characteristics 243 6.1.2.1 Frequencies 243 6.1.2.2 Polarization 243 6.1.2.3 Side Bands and Side Lobes 244 6.1.3 Design 245 6.1.3.1 Subsystem Elements 245 6.1.3.2 Spacecraft Antenna Layout 248 6.1.3.3 Redundancies 251 6.1.4 Monitoring and Commanding 251 6.1.4.1 Automatic Gain Control 251 6.1.4.2 Loop Stress 252 6.1.4.3 Lock Status 253 6.1.4.4 Polarization Prediction 253 6.1.5 Operational Situations 254 6.1.5.1 Acquisition and Loss of Signal 254 6.1.5.2 Ranging 255 6.1.5.3 Doppler and Coherency 256 6.1.5.4 Antenna/Transponder Selection 256 6.1.6 Outlook to Future Developments 257 6.2 On-Board Data-Handling Subsystem Operations 257 6.2.1 Definition of Subsystem 257 6.2.2 Fundamentals 257 6.2.2.1 Subsystem Elements 258 On-Board Computer 259 Mass Memory Unit 259 Data Bus and Data Cable Harness 260 Additional Components 260 6.2.2.2 Redundancy 260 6.2.2.3 Telemetry Parameters 261 6.2.2.4 Telecommands 261 6.2.2.5 Spacecraft Database 261 6.2.3 Space to Ground Data Streams 263 6.2.3.1 Data Transport 263 6.2.3.2 Frame-Based Telemetry 263 6.2.3.3 Packet Data Structures 264 6.2.3.4 Packet Utilization Standard 266 6.2.3.5 TMTC and Security Management 266 Flow Control Mechanisms 266 Routing Mechanisms 268 Authentication 268 Encryption 269 6.2.4 OBDH Management 269 6.2.4.1 General 269 6.2.4.2 Safeguard Mechanisms 269 Fault Detection, Isolation, and Recovery 269 Safeguard Memory 271 6.2.4.3 On-Board Software Maintenance 272 Modifying the Mission Database 272 OBC Software Maintenance 274 6.2.4.4 Execution Management 274 Time-Tagging 274 On-Board Control Procedures 275 6.2.4.5 Mass Memory Management 276 Ring Buffer 276 File System 277 Linear Storage 278 6.2.5 Summary and Outlook 278 6.3 Power and Thermal Operations 279 6.3.1 PTS Design Aspects 279 6.3.1.1 Power System 279 Energy Sources and Storage 280 Solar Panels 281 Electrochemical Cells: Batteries 282 Electrochemical Cells: Fuel Cells 283 Radioisotope Thermoelectric Generators 284 Nuclear Fission (and Fusion) 284 Power Regulation, Conversion, and Distribution 286 6.3.1.2 Thermal System 289 Operational Needs 294 6.3.2 Operations 294 6.3.2.1 Preparation Phase 294 6.3.2.2 LEOP Operations 295 6.3.2.3 Routine Phase 296 Battery Discharge Process 297 Battery Charge Process 299 Battery Temperature and Performance 299 Thermal Subsystem 300 6.3.2.4 End of Life 302 6.3.3 Contingency Operations 303 6.4 Propulsion Subsystem Operations 305 6.4.1 Principle of Propulsion 305 6.4.2 Configurations of Propulsion System 308 6.4.2.1 Layout of a Bi-Propellant Propulsion System 308 6.4.2.2 Operational Configurations 309 6.4.3 Real-Time Operations 311 6.4.3.1 Monitoring During Quiescent Periods 311 6.4.3.2 Orbit Maneuvers 312 6.4.3.3 Isolation of Apogee Engine (GEO) 314 6.4.3.4 Autonomous Operations 315 6.4.4 Off-line Operations 316 6.4.4.1 Preparation and Calibration of Orbit Maneuvers 316 6.4.4.2 Propellant Mass Calculation 317 6.4.4.3 Center of Gravity Calibration 318 6.4.4.4 Lifetime Estimation 319 6.5 Attitude and Orbit Control Subsystem Operations 319 6.5.1 Introduction and Overview 320 6.5.2 Subsystem Description 321 6.5.2.1 Sensors 321 Sun Sensor 322 Earth Sensor 322 Star Sensors 323 Magnetometer 323 Gyroscopes 324 Space-Based Satellite Navigation Systems 324 Other Sensors 324 6.5.2.2 Actuators 324 Thrusters 324 Magnetic Torquer 325 Wheels 325 6.5.2.3 On-Board Control Unit 326 Generation of Control Arguments for Attitude Correction/Adjustment 326 AOCS Modes 327 Sub-Modes 328 Fault Detection, Isolation, and Recovery 329 6.5.2.4 AOCS Equipment Combinations and Redundancy 330 6.5.3 AOCS-Related Ground Operations 331 6.5.3.1 Basic AOCS Ground Activities 331 Monitoring 331 Support of Orbit and Attitude Maneuvers 332 Miscellaneous Activities 333 6.5.3.2 LEOP and IOT 333 Payload Checkouts 334 6.5.3.3 Contingency Operations 335 6.5.3.4 Support Tools for AOCS 336 6.5.4 Experience from Previous Missions 336 6.5.4.1 AOCS Degradation 336 6.5.4.2 Strange Wheel Behavior 337 6.5.4.3 Undocumented AOCS Feature 339 6.5.5 Summary 340 6.6 Repeater Operations 340 6.6.1 Repeater Subsystem 341 6.6.1.1 Functions of a Repeater Payload 342 6.6.1.2 Overview and Layout of a Repeater/Transponder 343 6.6.2 Repeater Operations 345 6.6.2.1 LEOP Operations 346 6.6.2.2 IOT Operations 346 6.6.2.3 Routine Operations 347 6.6.2.4 Contingency Operations 349 References 351 References to Sect. 6.1 351 References to Sect. 6.2 351 References to Sect. 6.3 352 References to Sect. 6.4 352 References to Sect. 6.6 352 Chapter 7: Special Topics 353 7.1 Human Spaceflight Operations 353 7.1.1 Introduction 353 7.1.2 Manned and Unmanned Missions 354 7.1.3 From a Satellite to a Living Place 354 7.1.3.1 Enhanced Satellite Subsystems 354 Thermal Control Subsystem 354 Electrical Power Distribution Subsystem 354 Data Management Subsystem 355 Communications Subsystem 355 Motion Control Subsystem 356 7.1.3.2 Environment Control and Life Support System 357 Atmosphere Control and Supply 357 Atmosphere Revitalization 357 Temperature and Humidity Control 357 Water Recovery and Management 358 Fire Detection and Suppression 358 7.1.3.3 Visiting Vehicles - Cargo 358 7.1.3.4 Extra-Vehicular Activity 360 7.1.4 Crew: Another Subsystem to Operate 361 7.1.4.1 Crew Safety 361 Emergencies 361 Avoidance of Hazards 362 7.1.4.2 Crew Health 362 7.1.4.3 Crew Communication 363 Space to Ground (S/G) Audio Communications 363 Written Communications via Operations Data File 363 Supporting Material 364 Timeline 364 7.1.5 Ground Support Operations 364 7.1.5.1 Mission Control Center 364 Flight Control Team 364 Columbus Control Center 365 7.1.5.2 Operations 366 Coordination 366 Operations Products: OPS Products 366 7.1.6 Future 367 7.2 Operations of On-Orbit Servicing Missions 368 7.2.1 Introduction 368 7.2.1.1 What is On-Orbit Servicing? 368 7.2.1.2 Motivations for OOS 369 7.2.1.3 Space Debris Mitigation 370 7.2.2 Examples of On-Orbit Servicing Missions 370 7.2.2.1 Manned OOS Missions 372 Repair of Skylab and Hubble Space Telescope 372 7.2.2.2 Studies for Commercial OOS Missions in GEO 372 From the Loss of TV-Sat 1 to ESS and OLEV 372 7.2.2.3 OOS Inspection Missions 374 MITEX 374 7.2.2.4 OOS Technology Demonstrations 375 Engineering Test Satellite ETS-VII 375 Demonstration for Autonomous Rendezvous Technology 375 Orbital Express 375 Outlook: Technology Mission DEOS 376 7.2.3 Challenges Operating Robotic OOS Missions 378 7.2.3.1 Flight Operation System 378 7.2.3.2 Ground Data System 379 7.2.3.3 Flight Dynamic System 379 7.2.4 Satellite Rendezvous 380 7.2.4.1 Orbit Mechanics in Local Orbital Frame 380 Clohessy-Wiltshire Equations 381 (1) Displacement: Trajectories After Release at a Radial Distance 382 (2) Displacement: Trajectories After Release at a Distance in V-Bar 383 (3) Impulsive Maneuver: Delta-V in Orbital Direction (V-Bar Hop) 384 (4) Impulsive Maneuver: Delta-V in Radial Direction (R-Bar Hop) 385 7.2.4.2 Mission Phases from Launch to Docking 386 (1) Typical Approach in LEO 387 (2) Typical Approach in GEO 388 7.2.4.3 Rendezvous Sensors 389 Angles Only Navigation 390 7.2.5 Satellite Capture 392 7.2.5.1 Communication Concept 392 Contact Duration 392 Interference and Shading 393 Teleoperations: Delay Time and Jitter 394 7.2.5.2 Interaction of Manipulator With Servicer Platform 394 7.2.5.3 Additional Aspects 394 7.2.6 Verification and Test Facilities 396 7.2.7 Summary and Outlook 397 7.3 Interplanetary Operations 398 7.3.1 Types of Interplanetary Missions 398 7.3.1.1 Fly-by Missions 398 7.3.1.2 Orbiting Missions 399 7.3.1.3 Landing Missions 400 7.3.2 The Challenges of Interplanetary Flight 401 7.3.2.1 Trajectory Dynamics 402 7.3.2.2 Energy for the Onboard Systems 402 7.3.2.3 Communications with Earth 404 7.3.3 Mission Control Approach 406 7.3.3.1 Specifics of Interplanetary Flight Operations 406 Long Signal Propagation Delay 406 Long Cruise to Target 406 Long Periods Outside Ground Contact 407 High Spacecraft Vulnerability 409 Complex, Variable Navigation and Attitude Control Operations 409 Limited Knowledge of the Target 410 7.3.3.2 Ground Contact Activities 410 7.3.3.3 Trajectory Determination 414 7.3.4 Special Operations 418 7.3.4.1 Planet Swing-by 418 7.3.4.2 Asteroid Fly-by 420 7.3.4.3 Planet Orbit Insertion 421 7.3.4.4 Landing Operations 422 7.3.5 Conclusions 422 7.4 Lander Operations 423 7.4.1 Overview 423 7.4.2 Landing Insertion 427 7.4.3 Various Landing Strategies 428 7.4.3.1 Entry and Landing Through an Atmosphere 428 7.4.3.2 Landing on Airless Bodies: The Moon 432 7.4.3.3 Landing on Asteroids and Comets 434 7.4.3.4 Penetrators 435 7.4.4 Surface Operations 435 7.4.4.1 Operations of Stationary Surface Elements 435 7.4.4.2 Rover Operations 438 7.4.5 Conclusions 441 References 441 References to Sect. 7.1 441 References to Sect. 7.2 441 References to Sect. 7.3 442 References to Sect. 7.4 442 Index 444