No one knows for certain why the signal from the Comet Nucleus Tour (CONTOUR) spacecraft disappeared on Aug. 15, 2002. CONTOUR was a Discovery Program mission that was left almost entirely in the hands of NASA contractors and academic partners. It was a mission lost because of poor communication, misguided assumptions and models that were not faithful to reality. The project team had no experience with the Solid Rocket Motor they used, and they relied on the SRM manufacturer and a consultant for expertise. The team also vested much in the strong success record of the particular model they used, but previous designs did not match CONTOUR's specifications. In this study of CONTOUR, look for ways to consider if your project is leaning on insufficient supports or depending on past performance.