FOREWORD This final report describes the design of the "Lunar Orbital Prospector" (LOP), a Lunar orbiting satellite designed by students at Utah State University. This design project has been completed under the sponsorship of NASA/OAST through the Universities Space Research Association (USRA). We at Utah State are very pleased with the results of this design effort. We are proud of the product, the LOP design, and we are excited about the achievement of all our learning objectives. The systems design process is one that cannot be taught, it must be experienced. The opportunity to use our maturing engineering and scientific skills in producing the LOP has been both challenging and rewarding. We are proud of the final design, but, equally important, we are grateful for the skills we have developed in identifying system requirements, spreading them into subsystems specifications, communicating with eachother in all sorts of technical environments, conducting parametric and trade-off studies, and learning to compromise for the good of the system. Elements of this design project have migrated into other forums. In late April, class members presented the final results to the monthly meeting of the Utah Section of the AIM. Also in April, Dr. Frank Redd and Mr. James Cantrell presented a paper on the LOP at the Lunar Bases and Space Activities in the 21st Century conference in Houston. A revised copy of that paper has been submitted for publication in a book to be published from the output of that conference. We wish to gratefully acknowledge the support of NASA/OAST and USRA, without which this experience could never happen. Mr. James Burke, our mentor from JPL, has provided mountains of technical data and a priceless reservoir of mature technical experience. It's been a great year. Frank J. Redd, PhD Professor, ME James N. Cantrell Student Manager CLASS PARTICIPANTS James Cantrell Systems Engineering Kyle Adams Structures Robert Schmid Structures and Thermal Control John Atkinson Structures Craig Christensen Orbits, Structures, and Thermal Control Perry Voyer Propulsion Oscar Monje Propulsion Kimberly Anderson Power, Structures Lorraine Barnum Radar Mapping Steve Brown Instrument Systems Ali Siahpush Attitude Control Greg McCurdy Raman Spectroscopy Bennett Keller Raman Spectroscopy Allison Goodworth Instruments Blake Crowther Power Pete Krull Power Roger Me 1ine Communications James Singer Communications Shelly Wegener Technical Writer Raymond LeVesque Advisement TABLE OF CONTENTS Executive Summary 1.0 Background 1.1 Lunar Prospecting 1.2 Lunar Geoscience Orbit 1.3 The Lunar Orbital Prospector 1.4 GTV 1.5 Mission Description 1.6 System Description 2.0 Remote Sensing the Moon 2.1 Reflectance Spectroscopy 2.2 Gamma Ray and X-Ray Spectroscopy 2.3 Subsurface Sensing 2.4 Conclusion 3.0 Environment 3.1 Environmental Parameters 3.1.1 History 3.1.2 Diversity 3.1.3 Lifeless 3.1.4 Dryness 3.1.5 Lunar Chemistry 3 .1.6 Gravity 3.1.7 Radiation and Particles from Space 3.1.8 Lunar Atmosphere and Surface Pressure 3.1.9 Lunar Surface Temperature 3.1.10 Moon Magnetism 3.1.11 Center of Mass 3.1.12 Moonquakes 3.2 Prospecting Parameters 3.2.1 Regolith Thickness 3.2.2 Regolith Composition 3.2.3 Lunar Rocks 3.2.4 Surface "Weathering" 3.2.5 Possible Sources for Mineral Concentration 4.0 Instrument Groups 4.1 LOP Mission Packages 4.2 Instrument Descriptions and Functions 4.2.1 Radar Altimeter 4.2.2 Gamma Ray Spectrometer (GRS) 4.2.3 Thermal Infrared Mapping Spectrometer (TIMS) 4.2.4 Visible and Infrared Mapping Spectrometer (VIMS) 4.2.5 Visible High Resolution Solid State Imager (VHRSSI) 4.2.6 Magnetometer and Electron Reflectometer 4.2.7 X-Ray Spectrometer 4.2.8 Ultraviolet Spectrometer 4.2.10 Microwave Radiometer 4.2.11 Laser Altimeter 5.0 Passive Packages 5.1 Metals and Radioactive Element Package 5.2 Thermal, Silicates and Water Package 6.0 Active Sensing Packages 6.1 Topographic Mapping Package 6.2 Raman Spectroscopy 7.0 Application of Raman Spectroscopy in Lunar Remote Sensing 7.1 Current Applications 7.2 Principles of Raman Spectroscopy 7.3 Lunar Orbiting Platform Application of Raman Spectroscopy 7.4 Laser Sources 7.5 Differences and Similarities to Infrared Spectroscopy 7.5.1 Surface Resolution Difference 7.5.2 Bandwidths 7.5.3 Spectra Difference 7.5.4 Intensity of Spectral Lines Difference 7.6 Mission Scenario 8.0 Radar Surface and Subsurface Mapping 8.1 Mission Objectives 8.1.1 Surface Mapper 8.1.2 Subsurface Mapper 8.2 General System Operation 8.3 The Instrument 8.3.1 Introduction 8.3.2 Introduction Hardware Components 8.3.3 Fixed Parameters 8.3.4 Experimental Parameters 8.4 Conclusion 9.0 Orbital Analysis 9.1 Constraints 9.1.1 Topography and Center of Mass 9.2 Gravity Field 9.3 Orbital Strategies 9.3.1 Orbital Considerations 9.3.2 High Resolution Strategies 9.3.3 Specific Missions 9.4 Fuel Consumption 9.4.1 Coplanar Orbital Maneuvers 9.4.2 Plane Changes 9.5 Conclusions 10.0 Propulsion System 10.1 Mineral and Element Concentrations 10.2 Lunar Production Processes 10.3 Lunar Oxygen Production 10.4 Lunar Hydrogen Production 10.5 Vacuum Reduction of Minerals 10.6 Lunar Derived Fuels from Human Wastes 10.7 Fuels Derived from Agricultural Wastes 10.8 Other Production Elements 10.9 Production Constraints 10.10 Production Rates 10.11 Processing Plant Sizing 10.12 Lunar-Derived Propellant Possibilities 10.13 Propellant System Quantities 10.14 Production Costs 10.15 Propellant System Decision 10.16 Effect of Rate of Fuel Production on LOP Mission 10.17 Establishing a Lunar Materials Processing Plant and Base 10.18 Propulsion System Analysis 10.19 Thrust Chamber 10.20 Liquid Oxygen System 10.21 Starting Problems 10.22 Future Considerations 10.23 Conclusion 11.0 Communications System 11.1 Introduction 11.1.1 Control and Maintenance 11.1.2 Data Transmission 11.2 Internal System Schematic 11.2.1 Optical Fiber System 11.2.2 Communication Computers 11.2.3 Antenna Modules 11.3 External Design 11.3.1 Antennanransceiver Units 11.3.2 Central Computer Module 11.3.3 Optical Storage Module 11.4 Data Format 11.4.1 Pulse Coded Modulation 11.4.2 Data Bit Rates 11.5 Power Budget 11.5.1 TransmitterDeceiver Power Requirements 11.5.2 Communication Computer/Storage Power Requirements 11.6 Size and Mass Budget 11.6.1 Transceiver/Antenna Size and Mass Budgets 11.6.2 Communications Computers Size and Mass Budget 11.7 Communication System Backup 11.7.1 Antenna Failure 11.7.2 Transmitter/Receiver Failure 11.7.3 Communications Computer Failure 11.7.4 Optical Data Bus Failure 11.8 Relay Sites 11.8.1 Ground Based Relay Stations 11.8.2 Satellite Relay Stations 12.0 Power System 12.1 Options and Considerations 12.2 Solar Array, Secondary Batteries 12.3 Thermal Power 12.4 Solar Array/Batteries/RTG's 12.4.1 Power Needs 12.4.2 Component Size 12.5 Solar Array Sizing 12.6 Design Parameters 13.0 Configuration and Structure 13.1 Configuration 13.1.1 Propulsion System 13.1.2 Altitude Thrust 13.1.3 Attitude Thrust 13.1.4 Module Support 13.1.5 Science Packages 13.1.6 Modularity 13.1.7 Other Modules 13.2 Sizing the Structure 13 .3 Materials 13.3.1 Lunar Materials 13.3.2 Earth Materials 13.3.2.1 Lightweight 13.3.2.2 Low Coefficient of Thermal Expansi n 13.3.2.3 Stiff 13.3.2.4 Vibration Resistant 13.3.2.5 Fatigue Resistant 13.3.2.6 Creep Resistant 13.3.2.7 Impact Resistant 13.4 Space Environment 13.4.1 Outgassing 13.4.2 Thermal Cycling 13.4.3 Radiation 13.5 Thermal Control 13.5.1 LOX Tank 13.5.2 Scientific Instruments 13.6 Conclusion 14.0 Thermal Considerations 14.1 Sources of Heat 14.1.1 Solar Radiation 14.1.2 Reflected Solar Radiation 14.1.3 Thermal Radiation from the Moon 14.1.4 Internally Generated Heat Loads 14.2 Radiation Out 14.3 Equilibrium Skin Temperature 14.4 Recommendations for Surface Coating 14.5 Special Problems 14.6 Conclusion 15.0 Design of a Bias Momentum Wheel 15.1 Theoretical Analysis and Equations of Iotion 15.2 The Pitch Loop 15.2.1 Root Locus of the Pitch Loop 15.3 The Rollflaw Loop 15.3.1 Root Locus of the Rollflaw Loop 15.3.2 Computer Simulation of the Rollflaw aop 15.4 Momentum Wheel Desaturation 15.5 Conclusion LUNAR ORBITAL PROSPEcrOR Utah State University Executive Summary One of the primary rationales for establishing a manned lunar presence is the possiblitiy of exploiting the Moon's resources. The Moon is known to be abundant in oxygen and various metals. Given the known resource potential of only a few explored lunar sites, the possibility of large deposits of these resources and other undiscovered reources elsewhere on the Moon seems highly likely. A continued search for lunar resources and exploration on a global scale in conjunction with a manned lunar base will aid in fully exploiting the Moon's resource potential. A remote sensing orbital mission, such as the planned Lunar Geoscience Orbiter (EO), is a necessary precursor to the development of a manned lunar base. The need for a mission of this nature, however, does not end with the establishment of the base. Long term observation of the Moon, a continued search for lunar resources with new techniques, and continued lunar science studies are paramount to understanding the Moon and fully benefitting from its total resource potential.
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