Prospects for Very Long-Range Mars Rover Missions

The longest distance traveled to date by a Mars rover is 45 kilometers (km), driven by Opportunity in 14 Earth years. The primary mission for Perseverance is expected to cover up to about 20 km in about 2 Earth years. In contrast, the recent Intrepid lunar rover mission concept study envisions driving about 1,800 km in 4 Earth years, benefitting from lower gravity, greater solar power availability, simpler concepts of operation, and much shorter communication latency with Earth. This raises questions of what fundamentally limits rover range on Mars and what new mission concepts might be possible if Mars rover range could be increased substantially. Assuming a few key technology advances, this paper will present a model for energy-limited driving range for a solar-powered rover in the 100 to 200 kilogram (kg) size range that shows that order of magnitude increases in driving range should be possible over goals for Perseverance. These technologies are (1) high-speed, heaterless mobility actuators, (2) avionics with much lower size, weight, and power (SWaP) and much greater onboard computing capability, and (3) more advanced algorithms for onboard autonomy that reduce the frequency of required interactions with human operators, or “ground-in-the-loop” (GITL) cycles. We will discuss three new classes of Mars rover missions that could be enabled by such capability. These are (1) more thorough exploration of individual geologic type localities, which requires total range on the order of 100 kilometers (km), (2) visiting two or more type localities in a single mission, which requires total range on the order of at least several hundred km, and (3) exploring the north polar layered deposits, where driving only about 10 km in one Mars summer might enable sampling roughly a million years of ice layers.