Historical RTG performance data through 2023

UPDATE STATUS: Active missions (except for Voyager) have been updated through mid-to-late 2023. ---------- Power values were collected from reputable and authoritative sources and organized into a tabular format of time versus normalized power. Normalized power is the power at a given time, divided by the power at the beginning-of-mission (BOM). BOM power for each mission is also provided. Because RTGs can take days to weeks to fully equilibrate with their environment, BOM power is defined here as the maximum RTG power produced over the first 30 days of the mission. For many missions, this will be the first data point. Other missions (e.g. Curiosity) will reach this maximum power level after several days. BOM for RTG missions does not have a consistent definition. For deep space or orbital missions, BOM is launch. For missions where the RTG was installed on the surface of an extraterrestrial body, BOM is either the landing date (e.g. Martian landers or rovers) or the date the RTG was installed (e.g. Apollo lunar missions). Some important pieces of context for each RTG mission are also provided above the table. Pedigree of the performance data for each mission in this dataset: SNAP-9A (Transit 5BN-1 and Tranist 5BN-2), SNAP-19B (Nimbus III), SNAP-19 (Viking 1 and Viking 2), SNAP-27 (Apollo), and Transit-RTG were obtained from graphs presented in G.L. Bennett, J.L. Lombardo, and B.L. Rock, “US Radioisotope Thermoelectric Generators in Space,” Nucl. Eng., 25(2), 49–58 (1984). SNAP-19 (Pioneer 10 and 11) was obtained from an internal memo published by Teledyne Energy Systems, Inc. (courtesy T. Hammel). Teledyne was the design and engineering agency in charge of the SNAP-19. MHW-RTG (LES 8 and 9) were obtained from the Cassini Final Technical Report (DOE/SF/18852-T97) published by Lockheed Martin. Lockheed was the prime contractor and system integrator for all silicon germanium RTGs (i.e. MHW-RTG and GPHS-RTG) at that time. MHW-RTG (Voyager 1 and 2) telemetry was obtained courtesy of E. Medina of the Jet Propulsion Laboratory. Due to recent issues with the Voyager spacecraft, a public data drop of Voyager telemetry has not occurred in a while. As a result, Voyager 1 and 2 data only go to August 2021. GPHS-RTG (Galileo) telemetry was obtained courtesy of R. Gershman of the Jet Propulsion Laboratory. GPHS-RTG (Ulysses) was obtained courtesy of the Mission Operations Manager N. Angold. GPHS-RTG (Cassini) performance data was obtained directly from mission control at the Jet Propulsion Laboratory. GPHS-RTG (New Horizons) telemetry was obtained courtesy of C. Hersman of the Applied Physics Laboratory. MMRTG (Curiosity and Perseverance) telemetry was obtained courtesy of E. Clarke and L. Rich of the Idaho National Laboratory, as well as S. Bux and S. Pinkowski of the Jet Propulsion Laboratory.