Small‐RPS Enabled Mars Rover Concept

Both the MER and the Mars Pathfinder rovers operated on Mars in an energy‐limited mode, since the solar panels generated power during daylight hours only. At other times the rovers relied on power stored in batteries. In comparison, Radioisotope Power Systems (RPS) offer a power‐enabled paradigm, where power can be generated for long mission durations (measured in years), independently from the Sun, and on a continuous basis. A study was performed at JPL to assess the feasibility of a small‐RPS enabled MER‐class rover concept and any associated advantages of its mission on Mars, The rover concept relied on design heritage from MER with two significant changes. First, the solar panels were replaced with two single GPHS module based small‐RPSs. Second, the Mossbauer spectroscope was substituted with a laser Raman spectroscope, in order to move towards MEPAG defined astrobiology driven science goals. The highest power requirements were contributed to mobility and telecommunication type operating modes, hence influencing power system sizing. The resulting hybrid power system included two small‐RPSs and two batteries. Each small‐RPS was assumed to generate 50 We of power or 620 Wh/sol of energy (BOL), comparable to that of MER. The two 8 Ah batteries were considered available during peak power usage. Mission architecture, power trades, science instruments, data, communication, thermal and radiation environments, mobility, and mass issues were also addressed. The study demonstrated that a new set of RPS‐enabled rover missions could be envisioned for Mars exploration within the next decade, targeting astrobiology oriented science objectives, while powered by 2 to 4 GPHS modules.