DEVELOPING A LIGHTWEIGHT MARTIAN SIMULANT AND A MINIATURE TRIAXIAL DEVICE FOR LUNAR AND MARTIAN SOILS by YURU LI ZIMMERMAN Submitted in partial fulfillment of the requirements For the degree of Doctor of Philosophy Dissertation Advisor: Professor Xiangwu Zeng Department of Civil Engineering CASE WESTERV RESERVE UNIVERSITY August 2016 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the thesis/dissertation of Yuru Li Zimmerman candidate for the degree of Ph.D.*. Committee Chair Xiangwu Zeng Committee Member Adel Saada Committee Member Xiong Yu Committee Member Weihong Guo Date of Dense 7/12/2016 *We also certify that written approval has been obtained for any proprietary material contained therein. TABLE OF CONTENTS LIST OF TABLES .......................................................................................................... VI LIST OF FIGURES ..................................................................................................... VIII ACKOWLEDGMENTS ................................................................................................. XI ABSTRACT ....................................................................................................................XII 1. INTRODUCTION............................................................................................1 1.1 History of Space Exploration ............................................................................ 1 1.2 Future of Space Exploration ........................................................................... 11 1.2.1 Why the Moon ...................................................................................... 11 1.2.2 Why Mars ............................................................................................. 14 1.3 Motivation for research ................................................................................... 15 1.4 Scope of Work .................................................................................................. 16 1.5 Outline of the Dissertation .............................................................................. 18 2. LITERATURE REVIEW .............................................................................19 2.1 Introduction ...................................................................................................... 19 2.2 Lunar environment .......................................................................................... 19 2.3 Lunar regolith .................................................................................................. 24 2.3.1 Formation of the lunar regolith .......................................................... 26 2.4 Lunar soil investigation ................................................................................... 28 2.4.1 Soil investigation on the Moon ............................................................ 28 2.4.1.1 Introduction .......................................................................................... 28 2.4.1.2 Robot Interaction ................................................................................. 30 I 2.4.1.3 Spacecraft Interaction ......................................................................... 35 2.4.1.4 Footprint Analysis ................................................................................ 37 2.4.1.5 Trenching Tests and Boulder Tracks ................................................. 38 2.4.1.6 Penetrometer Tests .............................................................................. 41 2.4.2 Investigation on returned lunar soil ................................................... 47 2.4.2.1 Apollo Soil Samples.............................................................................. 48 2.4.3 Engineering properties of lunar soil ................................................... 52 2.4.3.1 Introduction .......................................................................................... 52 2.4.3.2 Particle size and shape ......................................................................... 53 2.4.3.3 Specific Gravity .................................................................................... 59 2.4.3.4 Density ................................................................................................... 61 2.4.3.5 Compressibility .................................................................................... 68 2.5 Strength Properties Investigation ................................................................... 73 2.5.1 Introduction .......................................................................................... 73 2.5.2 Techniques for Measuring Soil Strength Properties ........................ 75 2.5.2.1 Direct Shear Test.................................................................................. 76 2.5.2.2 Torsional Ring Shear Test .................................................................. 79 2.5.2.3 Triaxial Test ......................................................................................... 80 2.5.3 Strength Properties of Lunar Soil ...................................................... 84 2.5.3.1 Laboratory Measurements of Shear Strength .................................. 85 2.6 Review of lunar soil simulants ........................................................................ 93 2.6.1 MLS-1.................................................................................................... 94 2.6.2 JSC-1 ..................................................................................................... 98 II 2.6.3 JSC-1A ................................................................................................ 102 2.6.4 GRC-3 ................................................................................................. 106 2.6.5 Other Lunar Soil Simulants .............................................................. 108 3. DEVELOPMENT OF A LIGHT WEIGHT MARTIAN SIMULANT ..110 3.1 Introduction .................................................................................................... 110 3.2 Mechanical Properties of Martian Soil ........................................................ 113 3.2.1 Particle Size Distribution .................................................................. 113 3.2.2 Bulk Density ....................................................................................... 114 3.2.3 Shear Strength .................................................................................... 115 3.3 Mechanical Properties of Martian Soil Simulant ....................................... 115 3.3.1 Particle Size Distribution .................................................................. 116 3.3.2 Bulk Density ....................................................................................... 117 3.3.3 Shear Strength .................................................................................... 117 3.4 Method for Creating the CWRU-1 Simulant .............................................. 118 3.5 Geotechnical Properties of CWRU-1 ........................................................... 120 3.5.1 Specific Gravity .................................................................................. 120 3.5.2 Particle Size Distribution .................................................................. 121 3.5.3 Maximum and Minimum Density .................................................... 122 3.5.4 Compressibility .................................................................................. 123 3.5.5 Shear Strength .................................................................................... 125 3.6 Conclusion ...................................................................................................... 128 4. DEVELOPMENT OF A MINIATURE TRIAXIAL TESTING APPARATUS ...............................................................................................130 III 4.1 Introduction .................................................................................................... 130 4.2 Apparatus Description................................................................................... 132 4.2.2 Loading Unit ....................................................................................... 138 4.2.3 Vacuum and Confining System ........................................................ 139 4.2.3.1 Vacuum Unit....................................................................................... 139 4.2.3.2 Confining Unit .................................................................................... 139 4.2.4 Measurement System ......................................................................... 140 4.2.4.1 Displacement Transducer and Load Cell ........................................ 140 4.2.4.2 Data Acquisition Instrument ............................................................ 141 4.2.5 Others .................................................................................................. 143 4.3 Types of Testing for the Miniature Triaxial Apparatus ............................ 144 4.4 Testing Procedures......................................................................................... 144 4.5 Testing Results ............................................................................................... 147 4.5.1 Triaxial Strength Tests for JSC-1A.................................................. 147 4.5.2 Triaxial Strength Tests for Standard Sand ..................................... 152 4.6 Calibration Tests ...........................................................................................