Systems Engineering Lessons from NASA's Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) Mission

The PACE observatory launched on 8 Feb 2024, enabling new ocean and atmospheric science products. This “in-house project” was conceived, designed, built, tested, and is operated by NASA's Goddard Space Flight Center in Greenbelt Maryland. Mission Systems Engineering is a key aspect of any large endeavor involving new technology developments, engineering trade studies, risk management, documenting design details, troubleshooting inevitable problems, resource management, operations planning and training, and continually challenging a highly skilled, motivated, and, at times, exhausted team to perform at their very best. The lead Mission Systems Engineer (MSE) carries the technical authority which is separate and independent from safety & mission assurance and management direction. Simply put, the mission systems team is the “technical consciousness” of a flight project. The relatively small team of systems engineers has the technical memory, scar tissue from past failures, fundamental knowledge of mission objectives, and deep discipline engineering experience to lead via influence and ensure the wider project team “does the right thing” across a realm spanning years of time, hundreds of people, thousands of decisions, and tens of thousands of technical pieces. This paper describes the organization and overview of the PACE mission and examines new and old lessons of mission systems engineering.