RTG For Interstellar Probes
RTG have been proposed for use on realistic interstellar precursor missions and interstellar probes. An example of this is the Innovative Interstellar Explorer (2003–current) proposal from NASA. A RTG using 241Am was proposed for this type of mission in 2002. This could support mission extensions up to 1000 years on the interstellar probe, because the power output would be more stable in the long-term than plutonium. Other isotopes for RTG were also examined in the study, looking at traits such as watt/gram, half-life, and decay products. An interstellar probe proposal from 1999 suggested using three advanced radioisotope power source (ARPS).
The RTG electricity can be used for powering scientific instruments and communication to Earth on the probes. One mission proposed using the electricity to power ion engines, calling this method radioisotope electric propulsion (REP).
Read more about this topic: Radioisotope Thermoelectric Generator