Design of a Lunar Rover Utilizing Hydrogen-Oxygen Fuel Cell Technologies A Thesis Presented in Partial Fulfillment of the Requirements for the Degree of Master of Science for Aeronautical and Astronautical Engineering in the Graduate School of The Ohio State University By Michael Phillip Snyder Graduate Program in Aeronautical and Astronautical Engineering The Ohio State University 2011 Master's Examination Committee: Dr. Meyer J. Benzakein, Advisor Dr. Gerald M. Gregorek Copyright by Michael Phillip Snyder 2011 Abstract Future exploration of the solar system will depend on new designs and technologies that are efficient and versatile. Roving systems have explored the Moon and Mars but current means of supplying power are fragile and inefficient, or are considered hazardous to launch. NASA’s Glenn Research Center developed criteria necessary for the design of a robotic lunar rover with an extended exploration time. In order to satisfy these requirements a versatile rover equipped with a hydrogen-oxygen fuel cell with a 1 kilowatt nominal power output was designed to operate in the lunar environment for longer than 5 years continuously. Scaled testing of the rover was performed to predict the performance of the lunar rover. Testing was performed at the Ohio State University’s Aeronautical and Astronautical Research Laboratory in order to determined drawbar pull and sinkage of the rover. Regolith mitigation strategies were investigated in order to prolong the life of the rover by limiting and eliminating contamination caused by the lunar dust. ii Dedicated to To Diane, Walter, Andrea and everyone else who has helped me along to reach the starting point of my journey. iii Acknowledgments I would like to thank my advisor, Dr. Meyer Benzakein for all of his help and guidance. I would also like to thank Dr. Paul Penko, Eric Joyce, and Joel Longo for their help with this project. iv Vita April 16, 1986………………………... Born, Sandusky Ohio, USA June 2004…………………………….. Diploma, Bellevue Senior High School June 14, 2009………………………… B.S., Aeronautical and Astronautical Engineering, The Ohio State University October- December 2009………………. Graduate Research Assistant, Aeronautical and Astronautical Engineering, The Ohio State University January- March 2010………………… Graduate Teaching Assistant, Aeronautical and Astronautical Engineering, The Ohio State University September- December 2010……………. Graduate Teaching Assistant, Mechanical Engineering, The Ohio State University January- March 2011………………… Instructor, Aeronautical and Astronautical Engineering, The Ohio State University April- June 2011…………… Graduate Teaching Assistant, Mechanical Engineering, The Ohio State University v Publications Snyder, M.P. and Joyce, E.R., Lunar Extra-Vehicular Activities and Colonization Strategies, AIAA SPACE 2008 Conference and Exposition, September 9-11, 2008, San Diego, California. Snyder, M.P. and Joyce, E.R., Optimization of Fuselage Design for a Sounding Rocket Using Composite Materials, 45th AIAA Joint Propulsion Conference and Exhibit, August 2-5, 2009, Denver, Colorado. Joyce, E.R. and Snyder, M.P., Solid Rocket Motor Design for a High Altitude Composite Rocket, 45th AIAA Joint Propulsion Conference and Exhibit, August 2-5, 2009, Denver, Colorado. Snyder, M.P. and Joyce, E.R., Robotic Lunar Rover Design Utilizing Fuel Cell Technologies and Regolith Mitigation Strategies, AIAA SPACE 2009 Conference and Exposition, September 14-17, 2009, Pasadena, California. Joyce, E.R. and Snyder, M.P., Lunar Legislation: Strategies for Developing and Protecting the Lunar Frontier, SPACE 2009 Conference and Exposition, September 14-17, 2009, Pasadena, California. Snyder, Michael and Eric Joyce. "Development of Active Rocket Guidance at The Ohio State University: a guidance system being constructed by undergraduate students." Ohio State Engineer Spring 2009: 06. Snyder, Michael and Eric Joyce. "Luna Plaustrum: building a test prototype lunar rover." Ohio State Engineer Spring 2009: 08-10. Snyder, M.P., Joyce, E.R. and Osborne, J.C., Component Propulsion System: A New Philosophy for Exploration, Space Propulsion 2010, May 3-6, 2010, San Sebastian, Spain. Snyder, M.P., et al, A Mars Utility Vehicle Design with Incorporated Regenerative Fuel Cell Technology and In-Situ Resource Utilization, 46th AIAA Joint Propulsion Conference and Exhibit, July 25-28, 2010, Nashville, Tennessee. Joyce, E.R., et al, Design of a Versatile Regenerative Fuel Cell System for Multi-Kilowatt Applications, SPACE 2010 Conference and Exposition, August 30- September 2, 2010, Anaheim, California. Snyder, M.P., et al, Mobile Instrument for Lunar Exploration Endeavors: The Design of a Fuel Cell Powered Lunar Exploration Vehicle, SPACE 2010 Conference and Exposition, August 30- September 2, 2010, Anaheim, California. Jedrey, R., et al, Preliminary Mars Ascent Rendezvous Study, SPACE 2010 Conference and Exposition, August 30- September 2, 2010, Anaheim, California. Dunn, J., et al, 3D Metal Printing in Space: Enabling New Markets and Accelerating the Growth of Orbital Infrastructure, Space Studies Institute Space Manufacturing 2010 Conference, October 29-31, Mountain View, California. vi Fields of Study Major Field: Aeronautical and Astronautical Engineering vii Table of Contents Abstract…………………………………………………………………………………... ii Dedication……………………………………………………………………………….. iii Acknowledgements……………………………………………………………………… iv Vita………………………………………………………………………………………. v List of Tables…………………………………………………………………………….. x List of Figures…………………………………………………………………………… xi Chapter 1: Background 1.1 Interplanetary Rover Exploration………………………………………... 1 1.1.1 Lunokhod…………………………………………………………... 1 1.1.2 Lunar Roving Vehicle……………………………………………… 2 1.1.3 Martian Rovers……………………………………………………... 3 1.1.4 Current Designs……………………………………………………. 4 1.2 Fuel Cell Technologies......………………………………………………. 5 Chapter 2: Requirements 2.1 Rover Design Requirements……………………………………………. 10 2.2 Mission Requirements………………………………………………….. 10 2.3 Regolith Mitigation……………………………………………………... 11 Chapter 3: Design and Testing 3.1 Design…………………………………………………………………... 13 viii 3.1.1 Base Station……………………………………………………... 13 3.1.2 Rover……………………………………………………………..16 3.2 Testing………………………………………………………………… 27 Chapter 4: Results……………………………………………………………………... 31 Chapter 5: Conclusions…………………………………………………………………37 References……………………………………………………………………………. 39 ix List of Tables Table 1: Mass Break Down……………………………………………………………... 17 Table 2: Range, Payload, and Velocity…………………………………………………. 19 Table 3: Parameters for Rover and Scaled Rover………………………………………. 29 Table 4: Theoretical Results……………………………………………………………. 32 Table 5: Experimental Results………………………………………………………….. 33 x List of Figures Figure 1: General Fuel Cell Operation………………………………………………….. 6 Figure 2: Flow-Through Fuel Cell and Water Separation Schemes……………………...7 Figure 3: Non-flow-through PEM Fuel Cell……………………………………………...8 Figure 4: Base Station…………………………………………………………………... 14 Figure 5: Male Port Adapter with Nozzles……………………..………………………. 16 Figure 6: Power Allotment……………………………………………………………... 18 Figure 7: Rover Frame………………………………………………………………….. 20 Figure 8: Stress Analysis of Frame…………………………………………………...… 21 Figure 9: Track System…………………………………………………………………. 22 Figure 10: Motor Performance………………………………………………………….. 23 Figure 11: Tread Design………………………………………………………………... 24 Figure 12: Rover with Navigation System……………………………………………… 26 Figure 13: Assembled Rover Front View (Dimensions in meters)……………………... 27 Figure 14: Assembled Rover Side View (Dimensions in meters)……………………… 27 Figure 15: Scaled Tread Pod……………………………………………………………. 28 Figure 16: Regolith Test Bin……………………………………………………………. 29 Figure 17: Sinkage Test………………………………………………………………… 31 Figure 18: Pressure Contours for Helium………………………………………………. 34 Figure 19: Velocity Contours for Helium………………………………………………. 35 Figure 20: Pressure Contours for Nitrogen……………………………………………... 35 xi Figure 21: Velocity Contours for Nitrogen……………………………………………... 36 xii Nomenclature A Area b Track Width ESA European Space Agency c Cohesion Factor F Force k Parameter GRC Glenn Research Center l Track Length H Hydrogen m Mass I Current n Valence Electrons JPL Jet Propulsion Laboratory p Normal Pressure LRV Lunar Roving Vehicle u Exponent of Deformation M Molar Mass x Length MCFC Molten Carbonate Fuel Cell v Velocity MSL Mars Science Laboratory z Sinkage NASA National Aeronautics and φ Internal Shearing Space Administration Resistance Angle O Oxygen Subscripts PAFC Phosphoric Acid Fuel Cell C Pressure-Sinkage PEM Proton Exchange Membrane c Cell R External Resistance d Density RTG Radioisotope Thermoelectric Generator n Normal SOFC Solid Oxide Fuel Cell t Track Sol Martian Day φ Pressure-Sinkage W Weight xiii Chapter 1: Background The ability to explore and examine unknown terrain is critical to the future exploration of our solar system. Future mission plans require the ability to stay, for an extended period of time, on the surface of the planetary body that is being explored as well as gather as much information as possible for subsequent missions (1). In order to extend the overall time of exploration while simultaneously reducing the cost of a mission, robotic exploration is a vital method to examine the surface of a planetary body. Specifically, the exploration of the lunar surface cannot be fully completed without, at minimum, the aid of robotic rovers due to the extreme and hazardous environment. Currently, only one type of vehicle has remotely explored the Moon and several others have travelled to Mars. A new type of rover,