I'm no substitute for our dear Shuttlepedia, Shuttle_Guy, but I'll give it a shot <img src="/images/icons/wink.gif" /><br /><br /><Disclaimer: All that follows is Random-ass educated guessing /> Back in the '60s, it seemed the more complex/advanced you made a vessel, the better it turned out to be. With Mercury, huge achievements were made for that time, but it didn't even have an on-board computer. All navigational info was sent via radio to the astronauts who made the adjustments to the instruments. Then came Gemini, with enough technology to make Mercury seem more then a decade old with its advanced instrumentation and on board navigation computer etc, then of course, Apollo. With even more complex technology and a grander goal. <br /><br />So far, each project was more complex then the previous one and also more successful. So my guess is that as they designed the Shuttle, it didn't seem like such a bad idea to increase the complexity of the system. 1: So far that didn't go bad. And 2: It would make it harder for the Soviets, who were eager to redeem their space program, to copy the designs. At least those of certain parts.<br /><br />So perhaps it isn't so much an example of Build-and-Fix as much as a Build-and-Improve that, eventually mutated into a Build-and-Fix.<br /><br />Generally, I don't know what i'm talking about when it comes to the design strategies, but I thought about this very question a week or so ago, and this seemed like the most logical answer to me. Apologies for hijacking the question.