The development and delivery of the power sources for the Galileo mission to explore Jupiter and the Ulysses mission to explore the Polar regions of the Sun presented a number of technical and management challenges to the spacecraft power community. This paper explores the relationships between the government, industry, and the national laboratories through examination of specific technical issues and shows how a check‐and‐balance approach coupled with a cooperative focus on meeting the mission requirements led to the successful completion of the program.