Composition Sensors Calibration and Characterization and Warmup Analysis for the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) Presented By Maya Nasr B.S. Aerospace Engineering Massachusetts Institute of Technology, 2018 Submitted to the Department of Aeronautics and Astronautics as a fulfillment of the requirement for a Master’s Degree in Aeronautics and Astronautics at the Massachusetts Institute of Technology February 2021 © 2021 Massachusetts Institute of Technology. All rights reserved. Signature of the Author ___________________________________________________________ Maya Nasr Graduate Student Department of Aeronautics and Astronautics Signature of Faculty Advisor _______________________________________________________ Jeffrey A. Hoffman Professor of the Practice Department of Aeronautics and Astronautics Signature of Graduate Chair _______________________________________________________ Zoltán S. Spakovszky Professor, Aeronautics and Astronautics Chair, Graduate Program Committee 1 2 Composition Sensors Calibration and Characterization and Warmup Analysis for the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) Presented By Maya Nasr Submitted to the Department of Aeronautics and Astronautics on December 18, 2020 in partial fulfillment of the requirements for the Degree of Master of Science in Aeronautics and Astronautics Abstract MOXIE, the Mars Oxygen In-Situ Resource Utilization Experiment, is one of the payloads that is being carried on the Mars 2020 Perseverance rover. MOXIE was developed by MIT and NASA's Jet Propulsion Laboratory (JPL) to demonstrate, for the first time, In-Situ Resource Utilization (ISRU) on another planet by extracting O2 from CO2 in the Martian atmosphere using solid oxide electrolysis (SOE). In order to inform and control its system, MOXIE has a set of temperature, pressure, and composition sensors that measure its internal gas flows. The four composition sensors are commercial off-the-shelf (COTS) hardware and include an oxygen sensor (0 – 100%) and a carbon dioxide sensor (0 – 5%) for the output gas stream from the SOE anode (expected to be pure oxygen) and another carbon dioxide sensor (0 – 100%) and a carbon monoxide sensor (0 – 100%) for the cathode (a mixture of CO2 and CO). Except for the luminescence oxygen sensor, all of these composition sensors are Non-Dispersive Infrared Radiation (NDIR) sensors produced for Earth-ambient-conditions. The research presented in this thesis involves a series of tests under a range of temperatures, pressures and concentrations in order to properly calibrate and characterize (C&C) the sensors to understand their future behaviour on Mars prior to their flight on the Mars 2020 rover. In order to simulate Mars conditions and conduct the C&C tests, this research involved designing and constructing a temperature-controlled vacuum chamber. Following a set test plan, numerous sensor readings were recorded while varying the chamber gas composition, pressure and temperature. The main motivation for this research is to extend the sensor manufacturer’s results, which were designed for operation in stable terrestrial pressure and temperature regimes with frequent calibration, to a Martian environment with large dynamic pressure and temperature swings, variable ratios of gases with cross-sensitivity, and limited ability to calibrate in-situ. This research is critical in characterizing and calibrating the MOXIE sensors prior to their flight on the Mars 2020 rover, in order to be able to correctly interpret their readings. This thesis also covers the work on the thermal data processing and analysis of the warmup period of the heaters in MOXIE. It focuses on understanding the warmup duration, power and energy expenditure, and the heat loss models. This is critical both for planning operations on Mars and for analyzing the thermal control system and energy profiles. 3 Thesis Supervisor: Jeffrey Hoffman Title: Professor of the Practice of Aerospace Engineering 4 Acknowledgements This research would have not been possible without the combined efforts and support from many people. First and foremost, thank you to my advisor, Professor Jeffrey Hoffman, for everything you have done since my very first aerospace engineering class with you during my freshman year of my undergraduate degree at MIT, up until this moment. Thank you for believing in your students and treating us as family. I would not have been able to persevere through some of my most difficult periods at MIT, especially this year, without your genuine kindness, support, and understanding. I am very fortunate to be advised by you. Thank you to the MOXIE Principal Investigator, Mike Hecht, for your invaluable guidance in this research. Your knowledge and expertise are always inspiring, and I’m looking forward to your continued support during my PhD. Thank you to the MOXIE team at NASA Jet Propulsion Laboratory (JPL) and outside, particularly to Marianne Gonzalez for your constant help in the sensor LabVIEW VI’s, to Joel Nissen, who never hesitated to generously offer his time and expertise to help in this work, to Asad Aboobaker for your resourcefulness in answering any questions, and to Donald Rapp for your time and patient guidance in the warmup analysis work. A big thank you to Forrest Meyen for taking me in as a UROP for MOXIE during the end of my sophomore year of my undergraduate degree at MIT. That was one life-changing step in my research path. I am also deeply thankful for Eric Hinterman and my UROP Alex Forsey, both of whom were fundamental parts of this research at every step of the process. My biggest thank you goes to my family—my wonderful mom and dad, Akhlas and Radwan, and my amazing brother, Samir. You are the main reason I was able to believe in my dreams, leave Lebanon and come to MIT in 2014. Thank you for being there for me at every step of the way, despite the horrific circumstances in Lebanon. You mean more than anything in the world to me, and I wish I were able to be closer to you to celebrate my degree. I owe the three of you everything! Thank you to all my friends both inside and outside of MIT for making every day fun and memorable and for being always there for me both in every difficult and every happy moment. A special thank you to my best friend, Safa, for being my constant emergency contact and go-to person throughout all my years at MIT. I would finally like to thank my funding sources. The work in this paper was supported with funding from the MOXIE team supported by three NASA directorates: The Human Exploration and Operations Mission Directorate (HEOMD), the Space Technology Mission Directorate (STMD), and the Science Mission Directorate (SMD). 5 Table of Contents ABSTRACT ...................................................................................................................................................3 ACKNOWLEDGEMENTS ...........................................................................................................................5 LIST OF FIGURES ........................................................................................................................................7 CHAPTER 1: INTRODUCTION ............................................................................................................10 1.1 MARS EXPLORATION .....................................................................................................................10 1.2 MARS IN-SITU RESOURCE UTILIZATION (ISRU) ...................................................................11 1.3 MOXIE ......................................................................................................................................12 CHAPTER 2: MATERIALS AND METHODS .....................................................................................15 2.1 MOXIE GAS COMPOSITION SENSORS .....................................................................................15 2.2 CHARACTERIZATION AND CALIBRATION (C&C) ...................................................................19 2.3 VACUUM CHAMBER AT MIT .....................................................................................................20 2.4 MIT EXPERIMENTAL TESTING PLAN .....................................................................................27 CHAPTER 3: THEORY AND CALCULATIONS.................................................................................33 3.1 THE BEER-LAMBERT LAW FOR GAS ABSORPTION .................................................................33 3.2 OXYGEN LUMINESCENT SENSING ...........................................................................................37 CHAPTER 4: RESULTS ...........................................................................................................................39 4.1 EXPERIMENTAL TESTS AT MIT ...............................................................................................39 4.1.1 CS1, CS2 and CS3 ..................................................................................................................39 4.1.2 CS4 .........................................................................................................................................52 4.2 ERROR STUDY ...........................................................................................................................54 CHAPTER 5: DISCUSSION ....................................................................................................................58 CHAPTER 6: NEXT STEP PLANS ........................................................................................................59