"Crawl, Walk, Then Run” – Simple Planner’s Incremental Roll-Out in Perseverance Operations

—The Simple Planner (SP), a concept of operations(con-ops) facilitating autonomous scheduling onboard Mars2020’s Perseverance rover, is a milestone in terms of scale andvisibility of autonomy in space missions. At the core of SP liesthe Onboard Planner (OBP) software which governs thetranslation of a human operator's desired set of activities into amalleable schedule wherein activities can grow or shrink induration, shift earlier or later in time, and where the real-timeaccounting of onboard resources allows the rover software tooptimize scheduling via incremental adjustments. Achieving theefficiency objectives of SP over the life of the Perseverancemission requires a smooth and careful transition so that themission system can iteratively characterize and address thechallenges ahead. To this end, SP is being rolled out in twophases (SP1 and SP2) across multiple ground software andflight software releases, with increasing capability, and thedeployment into its first phase is underway in 2023. Thesephases fall within a “crawl, walk, then run” implementationstrategy. In this model, the “crawl” encompasses the predeployment readiness testing and checkouts which includemission system end-to-end exercises such as SP1 First-TimeActivities, thread tests, and Operational Readiness Tests,recently executed at the Jet Propulsion Laboratory (JPL) andon Mars. Baseline SP1 flight operations – the "walk" –preserves the general structure of the original master/submaster design in scheduling, while recouping time and energyby allowing the scheduler to recognize when activities end, andthen adjust, rather than adhering to all ground-conceivedconservative margins. SP2 (the "run") expands the schedulingautonomy to prioritize amongst mandatory and optionalactivities while adhering to operational constraints. This paperwill center on the details of this "crawl, walk, then run" process.Specifically, in this discussion we will provide an overview of themission system implications for each phase of SP, as well asdescribing the latest available results to date from “the crawl.”This investigation will draw on operational lessons that we arecontinuing to learn in the early days of SP roll-out, and willsummarize the unique challenges that have come fromintegrating significant autonomous decision-making into aFlagship space mission.