Preface	6
	Book Overview	16
	Contents	7
	About the Authors	14
	Chapter 1: The Space Environment	19
	1.1 The Environment	19
	1.1.1 The Earth Magnetic Field	19
	1.1.2 Solar Energy	21
	1.1.3 Residual Atmosphere	21
	1.1.4 Gravity and Gravity Gradient	23
	1.2 The Earth and Spacecraft Coordinate System	23
	1.3 Other Space Environmental Matters	25
	Chapter 2: Satellite Missions	26
	2.1 Satellite Orbits	26
	2.2 Satellites Today	27
	2.3 Satellite Imaging	30
	2.3.1 Imaging Payload Fundamentals	32
	2.3.2 The Telescope	33
	2.3.3 Image Quality	35
	2.3.4 Adequacy of the Light Input	36
	2.3.5 Image Integration (Exposure) Time	38
	2.3.6 Pointing to a Target on the Ground	40
	2.3.7 Swath Width	43
	2.3.8 Spacecraft Agility and Targeting	45
	2.3.9 Imaging Spacecraft Attitude Sensing, Control Requirements	45
	2.3.10 Data Quantity and Downlink Data Rate	46
	2.3.11 An Imaging Scenario	47
	2.4 Satellite Constellations	48
	2.4.1 Present Constellations	48
	2.4.2 Coverage and Gaps	50
	2.4.3 Other Satellite Constellation Considerations	54
	Chapter 3: Orbits and Spacecraft-Related Geometry	55
	3.1 Acceleration of Gravity, Velocity, Period	55
	3.2 Position of Spacecraft as a Function of Time	56
	3.3 Spacecraft Elevation, Slant Range, CPA, Ground Range	58
	3.4 Pointing to a Target on the Ground From the Spacecraft	63
	3.5 Ballistic Coefficient and On-Orbit Life	65
	3.6 Computing the Projection of the Sun on Planes on the Spacecraft	67
	Chapter 4: Electric Power Subsystem Design	71
	4.1 Required Orbit Average Power (OAP)	72
	4.2 Battery Capacity and Battery System Design	73
	4.2.1 Battery Capacity	73
	4.2.2 Battery Choice	75
	4.3 Solar Arrays Configuration	76
	4.4 Beta Angle Vs. Time	81
	4.5 Solar Cells and Cell Laydown	81
	4.6 EPS Block Diagram	82
	Chapter 5: Spacecraft Communications	85
	5.1 Frequency Allocation	85
	5.2 Modulation Types	87
	5.3 Bit Error Rate (BER) and Forward Error Correction (FEC)	88
	5.4 Link Equations	89
	5.5 Spacecraft Antennas	92
	5.5.1 The N-Turn Helix Antenna	92
	5.5.2 Half Wave Quadrifilar Helix Antenna	93
	5.5.3 The Turnstile Antenna	94
	5.5.4 The Patch Antenna	94
	5.5.5 Horn Antennas	95
	5.5.6 Dish Antennas	96
	5.5.7 Intersatellite Links and Steerable Antennas	97
	5.5.8 Phased Arrays	98
	5.5.9 Deployable Antennas	98
	5.6 Increasing Throughput by Varying Bit Rate or Switching Antennas	98
	5.7 Geometrical Constraints on Space-to-Ground Communication	100
	5.8 RF Subsystem Block Diagram	101
	Chapter 6: Spacecraft Digital Hardware	103
	6.1 Computer Architecture	103
	6.2 Computer Characteristics and Selection	105
	6.3 Spacecraft Computers Available Today	105
	Chapter 7: Attitude Determination and Control System (ADACS)	107
	7.1 ADACS Performance Requirements Flowdown	107
	7.2 Description of the Most Common ADACS Systems	109
	7.2.1 Gravity Gradient Stabilization	109
	7.2.2 Pitch Bias Momentum Stabilization	111
	7.2.3 3-Axis Zero Momentum Stabilization	113
	7.2.4 Magnetic Spin Stabilization	114
	7.3 The ADACS Components	115
	7.3.1 Reaction Wheels and Sizing the Wheels	115
	7.3.2 Torque Coils or Rods: Momentum Unloading	116
	7.3.3 Star Trackers	118
	7.3.4 GPS Receivers	121
	7.3.5 Other ADACS Components	122
	7.3.6 The ADACS Computer and Algorithms	122
	7.3.7 ADACS Modes	123
	7.4 Attitude Control System Design Methodologies	124
	7.5 Integration and Test	128
	7.6 On Orbit Checkout	130
	Chapter 8: Spacecraft Software	131
	8.1 Functions and Software Architecture	132
	8.2 Performing Each Function or Module	134
	8.2.1 Initialization of the CDH Processor, Hardware, and Operating System	134
	8.2.2 Executing Scheduled Events	134
	8.2.3 Stored Command Execution	135
	8.2.4 Housekeeping	136
	8.2.5 Management of the On-Board Electric Power System	136
	8.2.6 Management of the On-Board Thermal Control System	137
	8.2.7 Telemetry Data Collection	137
	8.2.8 Communications Software	138
	8.2.9 Attitude Control System Software	139
	8.2.10 Uploadable Software	139
	8.2.11 Propulsion Control System Software	140
	8.3 Software Development	140
	Chapter 9: Spacecraft Structure	142
	9.1 Introduction	142
	9.2 Requirements Flow-Down and the Structure Design Process	143
	9.3 Structure Options, Their Advantages and Disadvantages	145
	9.4 Structure Materials and Properties	151
	9.5 Fasteners	152
	9.6 Factors of Safety	153
	9.7 Structural Analyses	154
	9.7.1 Structural Analysis Overview	154
	9.7.2 Structural Analysis Steps in Detail	155
	9.8 Weight Estimate	169
	Chapter 10: Deployment Mechanisms	175
	10.1 Deployment Devices	176
	10.1.1 Hinges	176
	10.1.2 Deployable Booms	176
	10.1.3 Large Deployable Antennas	178
	10.2 Restraint Devices	179
	10.2.1 The Explosive Bolt Cutter	179
	10.2.2 Electric Burn Wires	180
	10.2.3 Solenoid Pin Pullers	181
	10.2.4 Paraffin Pin Pushers	182
	10.2.5 Motorized Cams or Doors	182
	10.2.6 Separation System	182
	10.2.7 Dampers	183
	10.2.8 Fluid Dampers	183
	10.2.9 Magnetic Dampers	184
	10.2.10 Constant Speed Governor Dampers	184
	10.3 Choosing the Right Mechanism	184
	10.4 Testing Deployables	185
	Chapter 11: Propulsion	186
	11.1 The Basics	186
	11.2 Propulsion Systems	189
	11.2.1 Cold Gas Propulsion System	189
	11.2.2 Hydrazine Propulsion System	191
	11.2.3 Other Propulsion Systems	192
	11.3 Propulsion System Hardware	192
	11.4 Propulsion Maneuvers	194
	11.4.1 Maneuvers for Spacecraft in a Constellation, Maintaining and Getting to Station	194
	11.4.1.1 Station Keeping	194
	11.4.1.2 Getting on Station	196
	11.4.1.3 Thrust Duration	198
	11.4.1.4 Hohmann Transfer Orbit Maneuver	198
	11.5 Other Propulsion Requirements	198
	Chapter 12: Thermal Design	200
	12.1 The Thermal Environment	201
	12.2 Heat Absorption	204
	12.3 Heat Rejection	205
	12.4 Heat Generated by the Spacecraft Electronics	205
	12.5 Tools Available for Altering Spacecraft Thermal Performance	206
	12.5.1 The Impact of Surface Finishes	206
	12.5.2 Thermal Conduction	207
	12.5.3 Conducting Heat across Screwed Plates or Bolt Boundaries	208
	12.5.4 Heat Pipes	208
	12.5.5 Louvers	209
	12.5.6 Heaters	209
	12.6 Constructing a Thermal Model of the Spacecraft	210
	12.7 A Point Design Example	210
	12.8 Thermal and Thermal Vacuum Testing	212
	12.9 Model Correlation to Conform to Thermal Test Data	213
	12.10 Final Flight Temperature Predictions	213
	Chapter 13: Radiation Hardening, Reliability and Redundancy	215
	13.1 Radiation Hardening	215
	13.1.1 Total Dose	215
	13.2 Reliability	218
	13.3 Redundancy	220
	Chapter 14: Integration and Test	221
	14.1 Component Level Testing	221
	14.1.1 The “Flat-Sat”	223
	14.2 Spacecraft Level Tests	223
	14.3 Environmental Testing	224
	14.3.1 Vibration Tests	224
	14.3.2 Thermal Test	230
	14.3.3 Bakeout	231
	14.3.4 Thermal Vacuum Test	232
	Chapter 15: Launch Vehicles and Payload Interfaces	234
	15.1 Present Launch Vehicles	234
	15.2 Launch Vehicle Secondary Payload Interfaces	236
	15.3 Secondary Payload Environment	240
	15.3.1 Vibration Levels	240
	15.3.2 Mass Properties	242
	15.3.3 Insertion, Separation and Recontact	242
	15.3.4 RF Environment	242
	15.3.5 Acoustic Environment	243
	15.3.6 Shock Environment	243
	15.3.7 Additional Spacecraft Environmental and Other Factors	244
	15.4 Analyses, Documentation and Other Factors	244
	Chapter 16: Ground Stations and Ground Support Equipment	246
	16.1 Ground Stations	246
	16.2 Ground Support Equipment	249
	16.3 Ground Station Manual and Operator Training	249
	16.4 Other Ground Station Matters	250
	Chapter 17: Spacecraft Operations	251
	17.1 Ground Station Functions for Spacecraft/Payload Operation	251
	17.1.1 The Map and Access Time Interval Display	252
	17.1.2 Telemetry Monitoring	253
	17.1.3 Spacecraft Command Generation	255
	17.1.4 Anomaly Discovery and Resolution	255
	17.1.5 Archiving TTM and Data	256
	17.2 Data and Data Rate Limitations	256
	17.3 Other Ground Station Operations	256
	17.3.1 Post Launch and Checkout	256
	17.3.2 Test Plans and Reports	257
	17.3.3 Manning the Ground Station	257
	17.3.4 Cost of Spacecraft Operations	257
	17.3.5 Operator Training and the Spacecraft Simulator	258
	17.3.6 Mission Life Termination	258
	17.3.7 Ground Station Development Schedule	258
	Chapter 18: Low Cost Design and Development	259
	18.1 Approach to Low Cost	259
	18.2 The Contract Should Focuses on Functional Rather than Technical Specifications	260
	18.3 Experienced, Small Project Team	260
	18.4 Vertical Integration	261
	18.5 Short Schedules and Concurrency of Development and Manufacturing	261
	18.6 Make Major Technical and Cost Trade-Offs Rapidly and Decisively	262
	18.7 Production Coordinator to Expedite Manufacturing	262
	18.8 Do Not Try to Save Money in Testing	263
	18.9 Holding Program Budget Responsibility Tightly	263
	18.10 Conclusion	264
	Chapter 19: Systems Engineering and Program Management	265
	19.1 Introduction	265
	19.2 Top Level Requirements	265
	19.3 Requirements Flowdown	266
	19.4 Multiple Approaches	267
	19.5 Trade Studies	267
	19.6 Selection of a Point Design	268
	19.7 Concept of Operations	268
	19.8 Preliminary Design Review (PDR)	268
	19.9 Interface Control Documents (ICDs)	269
	19.10 Detail Design	269
	19.11 Critical Design Review (CDR)	269
	19.12 System and Mission Simulations	270
	19.13 Test Bed and “Flatsat”	270
	19.14 Statement of Work	270
	19.15 The Work Breakdown Structure	270
	19.16 Cost	283
	19.17 Scheduling	284
	19.18 Critical Path	284
	19.19 Schedule Slack	285
	19.20 Earned Cost	285
	19.21 Cost to Complete Calculation	285
	19.22 Requirements Creep and Engineering Change Proposal.	286
	19.23 Reallocating Budgets, Cost Management	286
	19.24 Documentation	286
	19.25 Test Plans and Test Reports	287
	Chapter 20: A Spacecraft Design Example	288
	20.1 The Spacecraft Mission Requirements	288
	20.2 Derived Technical Requirements	288
	20.3 Preliminary Design	291
	20.4 Design Steps	292
	Chapter 21: Downloadable Spreadsheets	293
	Appendix 1: Tensile Strengths of SS Small Screws	295
	Appendix 2: NASA Structural Design Documents Accessible at http://standards.nasa.gov	296
	Appendix 3: Temperature Coefficients of Materials	297
	Appendix 4: Hohmann Transfer Orbit	299
	Appendix 5: Elevation and Azimuth from Spacecraft to Ground Target for Various CPA Distances	301
	Appendix 6: Beta as a Function of Time (Date)	303
	Appendix 7: Eclipse Duration	304
	Glossary	306
	References	313
	Index	316