On February 18, 2021 the NASA Perseverance Rover Mission landed on Mars with a set of seven science instruments. One of these instruments, MOXIE, the Mars Oxygen ISRU (In-Situ Resource Utilization) Experiment, opened the era of ISRU on mission Sol 60 (April 20, 2021) with its first successful operation in producing oxygen by solid oxide electrolysis of the Mars atmosphere CO2. The development effort of the solid oxide electrolysis stack inside MOXE progressed from TRL3 to TRL6 in a period of 18 months, completing at TRL9 with the successful flight demonstration. OxEon Energy was at the core of the design, development, and production of the flight hardware in accordance with structural, mechanical, thermal, electrical, operational cycling, feed composition, outlet composition and mass requirements unlike any seen in previous applications of solid oxide fuel cells or electrolysis. This development effort focused heavily on analysis of design impacts on overall performance, as well as functional testing to validate those models.