Development and Execution of the Mars 2020 Perseverance Rover’s Sampling Strategy

A primary objective of NASA’s Mars 2020 Perseverance rover mission is to collect and store a scientifically compelling set of geologic samples from the martian surface for possible return to Earth. If returned, these samples would enable years of scientific investigation and discovery with more capable instrumentation than can be sized for a Mars rover. To maximize the efficiency and science return of sampling operations on Mars, the Mars 2020 Science Team developed a minimum set of required observations to be performed at each sampling site. These observations include use of all of Perseverance’s remote and proximity science instruments and are compiled in the Standardized Observation Protocol (or STOP List). STOP List observations, along with other required activities that enable engineering/robotic arm operations, were assembled into a strategically developed product called the Sampling Sol Path (SSP). The SSP outlines a sol-by-sol (daily) order of events at a sampling site, starting with the initial drive to the site, acquisition of engineering and STOP List observations, sample coring and processing, and drive away. The purpose of the SSP and STOP List is to ensure continuity and repeatability across sampling events, inform planning constraints and activity dependencies, and minimize tactical decision-making during operations. While the intent and overall format of the SSP remain constant, it is an evolving strategic product, responding to the evolving science and engineering needs to support sampling operations in Jezero crater. Despite the efficiency and repeatability enabled by the strategic SSP product, no two sampling events have looked the same on Mars. The SSP defines the absolute minimum set of activities and sols required to complete each sampling event. This strategy allows some flexibility to insert additional opportunistic science observations throughout the sol path, as long as these additions remain within the scope and sol allocation of Perseverance’s current science campaign. The SSP will continue to be utilized for the collection of Perseverance’s remaining samples to maximize operational efficiency while also allowing opportunities for discovery-driven science.