In scientific research, there are many examples of creativity arising from constraints. Archimedes' principle, for instance, was discovered, when Archimedes tried to determine whether a crown was made of pure gold without damaging the crown. In contrast, cosmic microwave background, evidence of the Big Bang, was discovered through the exploration of "noise" in the microwave receiver. In this lecture, I will introduce constraints and creativity in space science research, drawing from both our experiences and the history of science, and discuss constraints inherent in human decision-making processes.