Radioisotope thermoelectric generator (RTG) technology has a very long and incredibly successful history of providing heat and power to some of humankind’s most successful space exploration missions. Members of the community that support and maintain this technology often like to show the entire history of RTG performance on “The Graph.” Meant to impress, The Graph does its job in that regard. Unless you were connected to the right people, however, it was very difficult to get a copy of The Graph or its underlying data. This made it difficult for many to dive into the technical details or evaluate individual RTG performance from historical missions. To make matters worse, the performance for several missions in The Graph were incomplete. In 2020, with a little extra time on their hands thanks to COVID, the authors reached throughout the RTG community to locate and collate the missing RTG data. This information was then published as an open-source tabular Dataset. Users can now build their own version of The Graph or use the data for a more detailed analysis of RTG performance. Updates to the currently operating missions in The Dataset are expected to occur on a roughly annual basis. This Dataset represents the most comprehensive, authoritative, up-to-date repository of all RTG performance available today.