SPS Feasability Study SD76SA0239-2

Cover	1
Title Page	3
Foreword	5
Table of Contents	7
Section 1. Introduction	19
1.1 Study Approach	19
1.2 Study Grond Rules and Assumptions	20
1.3 Study Results and Conclusions	23
Section 2. Concept Definition	29
2.1 Satellite Configuration	29
2.1.1 Configuration Concepts	29
2.1.2 Satellite Structure	30
2.1.3 Microwave Antenna Structure	40
Conclusions	49
2.2 Power Conversion	50
2.2.1 SPS Efficiency	50
2.2.2 Solar Cells and Blanket	51
2.2.3 Solar Reflectors	62
2.2.4 Slip Ring and Brush Assembly	69
2.2.5 Power Distribution	71
2.3 Power Transmission	80
2.3.1 DC-RF Conversion Devices	83
2.3.2 DC-DC Efficiency	85
2.3.3 Array Design and Waveguide Structures	87
2.3.4Phase Control of MPTS Transmit Array	99
2.3.5 Conclusions	104
2.4 Attitude Control/Stationkeeping	106
2.4.1 Reference Control System	106
2.4.2 Stationkeeping	110
2.4.3 Attitude Control	118
2.4.4 Attitude Control System Alternatives	119
2.4.5 Alternative Vehicle Configurations	129
Section 3. Orbital Operations	133
3.1 Structuress Fabrication	133
3.2 SPS Construction Jig/Base Complex	136
3.3 Mirror and Solar-Cell Blanket Fabrication Factilities	140
3.4 Rotary-Joint, Slip-Ring Structure and Electrical Buildup	142
3.5 Microwave Antenna Trunnion Structure Buildup	144
3.6 Microwave Antenna Assembly	144
3.7 Installation of Electronic Elements and Phased-Array Antenna	150
3.8 Maintenance Facilities	154
3.9 Crew Sizes and Assembly Sequence	156
Section 4. Transportation	157
4.1 Earth Launch Vehicle	157
4.2 Orbital Transfer	162
4.2.1 Earth-LEO Logistics Scenario	163
4.2.2 Orbital Transfer Vehicle	163
4.2.3 LEO-GEO Logistics Scenario	163
4.3 Crew and Resupply Module	167
4.4 Payloads Integration	169
Section 5. Programmatics	173
5.1 Program Development	173
5.2 Economic Comparisons	175
5.2.1 System Cost Estimates	175
5.2.2 Program Cost Relationships	178
5.2.4 Capital Investments and User Costs	184
5.3 Technology Advancement	192
5.3.1 Fabrication/Assembly Technology	192
5.3.2 Structures Technology	195
5.3.3 Solar Cell Technology	198
5.3.4 Microwave Transmission Technology	201
5.3.5 Ionospheric Interaction Technology	202
5.3.6 Transportation Technology	202
5.3.7 Attitude Control and Stationkeeping	204
5.3.8 Reflector Technology	206
5.3.9 Conductor and Switch Technology	207
5.3.10 Rotary Joint Technology	209
Section 6. Special Studies	211
6.1 Nuclear Radiation at Geosynchronous Orbit	211
6.2 Electrical Spacecraft Charging at Geosynchronous Orbit	218
6.3 SPS Microwave Radiations	223
Illustrations	9
Figure 1.1-1. Study Overview	20
Figure 1.2-1. SPS Reference Configuration	22
Figure 1.3-1. Assembly Schedule - Nth Satellite	25
Figure 1.3-2. Air-Augmented HTO SSTO Concept	25
Figure 1.3-3. SPS Cargo Traffic Model Cumulative Cargo Masses to Orbit	26
Figure 1.3-4. Program Cost Relationships	27
Figure 1.3-5. System Cost By Fiscal Year	28
Figure 1.3-6. Future Study Recommendations	28
Figure 2.1-1. SPS Reference Configurationthe	30
Figure 2.1-2. Configuration Alternatives	31
Figure 2.1-3. SPS Frame Girder Generation Sequence	32
Figure 2.1-4. SPS Structural Geometry	33
Figure 2.1-5. SPS Satellite Structure	34
Figure 2.1-6. Girder Intersection Variations	34
Figure 2.1-7. Beam Interface Attachments	35
Figure 2.1-8. Akron and Macon Frame Structure	36
Figure 2.1-9. Akron and Macon Partially Assembled	37
Figure 2.1-10. Hindenberg Partially Assembled	38
Figure 2.1-11. Beam Element Section for SPS Array Structure	39
Figure 2.1-12. Built-up Beam Element Section for SPS Array Structure	39
Figure 2.1-13. Normalized Sections	40
Figure 2.1-14. Existing MPTS Concepts	41
Figure 2.1-15. Structural Concept for Compression Frame/Tension Web MW Antenna	42
Figure 2.1-16. Tension Web/Compression Frame Interface	42
Figure 2.1-17. Design Loads	44
Figure 2.1-18. Compression Frame Analysis TechniqueN	45
Figure 2.1-20. Tribeam Personnel Scooter	47
Figure 2.1-19. Compression Frame Girder Configuration	46
Figure 2.1-21. Catenary Rope Design	48
Figure 2.1-22. Tension Web Design	48
Figure 2.2-1. SPS Efficiency	50
Figure 2.2-2. Solar Cell Spectral Response Comparisons	53
Figure 2.2-3. Typical 1 x 1 cm GaAlAs/GaAs Heteroface Solar Cell	54
Figure 2.2-4. I-V Characteristics of 1 x 1 cm^2 Cell Measured on X-25 Solar Simulator	55
Figure 2.2-5. Solar Cell Efficiency Projections	55
Figure 2.2-6. Solar Cell Efficiency	56
Figure 2.2-7. Normalized Solar Cell Maximum Power Versus 1-Mev Electron Fluence	57
Figure 2.2-8. Fractional Degradation in Short Circuit CurrentVersus 1-Mev Equivalent Fluence	59
Figure 2.2-9. Experimental Radiation Effects Data	59
Figure 2.2-10. Temperature and Radiation Effects on Solar Array Performance	60
Figure 2.2-11. Efficiency Versus Thickness (Optimum Conditions)	61
Figure 2.2-12. Solar Cell Configurations	63
Figure 2.2-13. Solar Cell Blanket Configuration	63
Figure 2.2-14. Vee Trough-Solar Cell Reflector System - Concentration Ratio and Dimensions as Function of Reflector	65
Figure 2.2-15. Vee Channel Solar Array Concentration Ratio as Function of Misorientation Angle	66
Figure 2.2-16. Simplified Solar Array Configuration	67
Figure 2.2-17. Panel and Reflector Steady-State Temperatures	69
Figure 2.2-18. Microwave Antenna Trunnion Structure Buildup	70
Figure 2.2-19. Microwave Antenna Hexagonal Compression Frame	70
Figure 2.2-20. Shoe and Slip Ring Drive Assembly	71
Figure 2.2-21. Pickup Shoe	72
Figure 2.2-22. Solar Array Conductor Network (One Quadrant)	75
Figure 2.2-23. Schematic of Solar Array Conductors	75
Figure 2.2-24. System Voltage DropsFigure	76
Figure 2.2-25. Conductor Cross-Section Area for Each of 4 SPS Modules	76
Figure 2.2-26. Total Array Conductor Weight of SPS	77
Figure 2.2-27. Conductor Weight	77
Figure 2.2-28. Power Distribution Lateral Power Flow	78
Figure 2.3-1. Conceptual Diagram Showing Array and Amplifier Cost Trends Versus Amplifier Size	81
Figure 2.3-2. Simplified Diagram of Klystron Mod-Anode and Beam Power Requirements	82
Figure 2.3-3. PPM/PM High-Efficiency Klystron CW Amplifier	84
Figure 2.3-4. Microwave Energy Conversion Efficiency Chain	86
Figure 2.3-5. Efficiency Breakdown - Transmitting Antenna	86
Figure 2.3-6. Raytheon MW Subarray Concept	87
Figure 2.3-7. Typical TE10 SWR Array	88
Figure 2.3-8. Amplitron Modified Heat Sink	90
Figure 2.3-9. Experimental RCR	91
Figure 2.3-10. Radiating Slot Plane (H-Plane)	92
Figure 2.3-11. Freedline Plane (E-Plane)	92
Figure 2.3-12. Far-Field Radiation Pattern (10-Square-Meter Subarray)	93
Figure 2.3-13. 10-Square-Meter Element Factor	93
Figure 2.3-14. RCR Element Maintenance	94
Figure 2.3-15. Low-Density 10-Square-Meter Subarray	95
Figure 2.3-16. Low-Density 30-Meter-Square Subarray	96
Figure 2.3-17. High-Density 10-Meter-Square Subarray	97
Figure 2.3-18. High-Density 30-Meter-Square Subarray	98
Figure 2.3-19. MW Antenna Modular Sizes	100
Figure 2.3-20. Functional Block Diagram of Hytrodyne Phase Control Network	102
Figure 2.3-21. SPS MPTS Transmit Array Geometry Using Space Feed Reference System	103
Figure 2.3-22. Microwave Power Transmission System	105
Figure 2.4-1. 100-cm Ion Thruster Single Cathode Concept	107
Figure 2.4-2. Summary of Engine Requirements	107
Figure 2.4-3. Inert Gas and Tankage Mass	109
Figure 2.4-4. Propulsion Requirement for Orbit Inclination Control	113
Figure 2.4-5. Satellite Motion	115
Figure 2.4-6. Canted Vehicle	121
Figure 2.4-7. Cant Angle Comparisons	121
Figure 2.4-8. Momentum Storage Requirements	123
Figure 2.4-9. Capabilities of Existing Devices	123
Figure 2.4-10. Momentum Wheel Design Parameters	124
Figure 2.4-11. Large Momentum Wheel Conceptual Design	124
Figure 2.4-12. Anaysis of Problem	125
Figure 2.4-13. Periodic Motion	127
Figure 2.4-14. Required Initial Conditions	128
Figure 2.4-15. Stable Oscillatory Motion	128
Figure 2.4-16. Control Requirements	130
Figure 2.4-17. Configuration B Period Motion	131
Figure 3.1-1. SPS Equilateral Triangle Beam Verendeel Truss-Formed Sheet	134
Figure 3.1-2. SPS Structural Element Fabricator	135
Figure 3.1-3. Tri-Beam Fabrication	136
Figure 3.2-1. SPS Construction Jig/Base Complex	137
Figure 3.2-2. Central Construction Base	137
Figure 3.2-3. Intersection Facility - Perspective View	138
Figure 3.2-4. Intersection Facility - Orthogonal Views	139
Figure 3.3-1. SPS Construction Facilities Operational	140
Figure 3.3-2. Solar Cell and Reflector Film Deployment Facility Center Vertex Crawler	141
Figure 3.3-3. Film Deployment Concept Cable System	142
Figure 3.3-4. Tribeam Personnel Scooter	143
Figure 3.3-5. Reflector and Solar Cell Film Installation	143
Figure 3.4-1. Rotary Joint, Slip-Ring Structure, and Electrical Track	144
Figure 3.4-2. Rotary Joint, Slip-Ring Structure, and Electrical Track Buildup	145
Figure 3.5-1. Microwave Antenna Trunnion Structure	145
Figure 3.5-2. Microwave Antenna Trunnion Structure Buildup	146
Figure 3.5-3. Beam Interface Attachments	147
Figure 3.6-1. Microwave Antenna Hexagonal Compression Frame	148
Figure 3.6-2. Microwave Antenna Hexagonal Compression Frame Buildup	148
Figure 3.6-3. Nth Satellite Assembly - 52nd Day	149
Figure 3.6-4. Microwave Antenna RF Element Installation - Negative Lens Configuration	149
Figure 3.6-5. Assembly Schedule - Nth Satellite	150
Figure 3.7-1. Central 30-Meter by 30-Meter Subarray in-Line Assembly Facility	151
Figure 3.7-2. Microwave Antenna 30-Meter by 30-Meter Subarray Modular Assembly and Installation	152
Figure 3.7-3. Microwave Antenna Modular Sizes	152
Figure 3.7-4. Microwave Antenna Elements - 3-Membrane Negative Lens Concept	153
Figure 3.7-5. Microwave Antenna Modules and Catenary Structure Assembly Sequence	153
Figure 3.7-6. Antenna Subarray Deployment Sequence	154
Figure 3.8-1. Microwave Antenna Maintenance Concept	155
Figure 4.1-1. Activity Matrix Cost Characteristics	158
Figure 4.1-2. Candidate Earth Launch Vehicle Concepts	158
Figure 4.1-3. Cost per Flight Comparisons	160
Figure 4.1-4. Air-Augmented HTO-SSTO Concept	161
Figure 4.2-1. Common Stage LO2/LH2 Concept	164
Figure 4.2-2. OTV Flight Profile	165
Figure 4.2-3. OTV Performance Capabilities	166
Figure 4.3-1• Passenger Module Mass Trend (No. of Passengers Versus Mass/Man)	168
Figure 4.3-2. Crew and Resupply Module	168
Figure 4.4-1. Payload Integration	169
Figure 4.4-2. SPS Cargo Traffic Model - Cumulative Cargo Masses to Orbit	170
Figure 4.4-3. SPS Cargo Traffic Model Supply and Demand Rates	170
Figure 5.1-1. SPS Program Breakdown Structure	173
Figure 5.1-2. SPS Program Development	174
Figure 5,2-1. Program Cost Relationships	179
Figure 5.2-2. System Cost by Fiscal Year	183
Figure 5.2-3. Economic Comparison-Example SPS Cash Flow Based on Estimated Investment Costs and Funds Generated by 4 Satellite Installations (Case la)	191
Figure 6.1-1. Van Allen Belt Particle Dose	213
Figure 6.1-2. Solar Flare Particle Dose	213
Figure 6.1-3. Galactic (Cosmic) Particle Radiation Dose	214
Figure 6.1-4. Total Nuclear Radiation Dose	214
Figure 6.1-5. Low-Altitude Van Allen Orbit Doses	215
Figure 6.2-1. Local Time Dependence of Phenomena	219
Figure 6.2-2. Secondary Electron Effects	221
Figure 6.3-1. Structure of Earth's Ionosphere•	226
Figure 6.3-2. RF Frequency Interference	227
Tables	13
Table 1.2-1. SPS Concepts	21
Table 1.3-1. Satellite Weight Estimates	23
Table 2.1-1. Compression Frame Girder Design	47
Table 2.1-2. Compression Frame/Tension Web MPTS Weight Statement	49
Table 2.2-1. SPS Solar Cell and Blanket Preliminary Specification	52
Table 2.2-2. Solar Cell Description and Weight	61
Table 2.2-3. SPS Reflector Preliminary Specification	64
Table 2.2-4. Optical Properties	67
Table 2.2-5. Array Temperature as Function of Substrate Emissivity	68
Table 2.2-6. Slip Ring and Brush Block Preliminary Specification	73
Table 2.2-7. Power Distribution Weights	79
Table 2.2-8. Design Concepts for Conductor Weight Reduction	79
Table 2.3-1. High-Efficiency 50-kw Klystron CW Amplifier-Estimated Weights for Different Focusing Schemes	84
Table 2.3-2. Theoretical Power Saving of RCR Over Conventional Standing Wave TE10 Slotted Arrays	89
Table 2.3-3. Effects of Linear Phase Error	100
Table 2.4-1. Satellite Propellant Requirements	108
Table 2.4-2. Reference Attitude Control System Mass Summary	110
Table 2.4-3. Configuration A Advantages	130
Table 2.4-4. Configuration B Advantages	131
Table 4.1-1. SPS Program Applicability - Costs	161
Table 4.1-2. SPS Program Applicability - Cost Projections	162
Table 4.2-1. Dual Ascent/Return AV Budgets (LEO = 300-n.mi. ~ Equatorial)	166
Table 4.3-1. Crew Rotation/Resupply Logistics ProfileA	167
Table 5.2-1. SPS Cost Summary	176
Table 5.2-2. Preliminary Economic/Financial Findings Based on Capital Investmen	187
Table 5.2-3. Economic Comparisons - SPS Cash Flow Performance Summary (Based on Estimated Investment Costs and Funds Generated By Profit and Depreciation & Amortization)	188
Table 5.2-4. SPS Cash Flow Summary Based on Estimated Investment Costs and Funds Generated By Profit and Depreciation and Amortization	189
Table 5.2-5. SPS Cash Flow Summary Based on Estimated Investment Costs and Funds Generated By Profit and Depreciation and Amortization	190
Table 5.3-1. Technology Advancement Requirements	193
Table 6.1-1. Time Dependences of Nuclear Radiations	211
Table 6.1-2. Recommended Astronaut Dose Limits	216
Table 6.1-3. Allowable Times Due to Radiation Doses	216
Table 6.2-1. History of Charging-Induced Phenomena	219
Table 6.3-1* SPS Microwave Radiations	223
Abbreviations	15

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