If a major project is truly innovative, you cannot possibly know its exact cost and its exact schedule at the beginning. And if in fact you do know the exact cost and the exact schedule, chances are that the technology is obsolete.As the discussion on 37S suggests, the word "obsolete" is rather strong. But then, the chap quoted here was Director of the Lunar Module Programme at Grumman. Working on Apollo probably gave you a rather different idea of what was obsolete from that of the average person. Or even the average engineer.
But the essence of the quote is absolutely right. And this is a crucial difference between manufacturing and creative engineering. Which of these things you think software development most resembles will have a big impact on what you think a plan looks like, and what sort of things you think are reasonable estimates to use to build that plan. That's not to say that in the case of innovation all bets are off: the Apollo Programme did meet JFK's deadline for putting a man on the moon and returning him to Earth (just).
But the next time you are starting a development project, getting set for iteration zero, or the inception phase, or whatever you call it, think about which parts of the project are innovative, and which are business-as-usual. Hint: using RoR to render SQL conversations over HTTP this time round instead of J2EE is not innovation. That's just no longer attempting to do you job with one hand tied behind your back. Second hint: the innovative bits are the ones that the business sponsors are really exited about and that the architect (don't pretend you don't have one) thinks are going to be "interesting" and that the project manager has to have a stiff drink before contemplating.
There are better ways to deal with the uncertainty that comes along with the huge promise of innovation, and, well... less good ones. You owe it to yourself (and your business sponsor) to figure out which aspects of the project you should be doing which way. Oh, and if the answer is mostly business-as-usual you owe it to the business to ask why the project is being done at all.