[A TidBit contribution from Ed Kostenbauder]
During one of the recent press conferences at JPL for the Mars Pathfinder mission (i.e. The Carl Sagan Memorial Station), the question was asked: "Realizing that unlike most space exploration projects, Pathfinder has very few backup or redundant systems, besides good people, what single thing has already made this mission successful?" One of the lead scientists (who is also a project manager) responded with "The success of the Pathfinder mission can be mainly attributed to starting with a good design, not necessarily a proven design (the design of Pathfinder was viewed by some as revolutionary), but by incorporating good design processes and techniques, and testing, testing, testing, testing... We continued testing the software until one week before Pathfinder was scheduled to land."