Inasmuch as we were designing a spacecraft that could not be flight-tested before its mission and could not be examined after its mission, we had to develop an elaborate and intensive ground test program that involved every level of vehicle integration. There is more, but it all worked and Apollo was a success. The position seems to be that a few failures can be tolerated if, in total, there are some successes. It seems to me that this approach entails real disadvantages. The cost of failure is more than the dollar loss.
Failure wastes the time and effort of our most valuable asset, our talented people.
Failure also delays the pace of the overall program. While the team at the Jet Propulsion Lab that produced the stunningly successful Pathfinder mission deserves great credit, it seems to me that the basic concept may have been flawed. If robotic exploration produces enough information and if the costs of the International Space Station have abated enough, a manned mission to establish an outpost appears both possible and desirable. An Apollo style round-trip mission looks to be very complex and costly. Robert Zubrin, in his book The Case for Mars , has suggested a better concept, making use of Mars resources.