I was reading this question about the clock drift on the Apollo missions and am sure that a drift of 1 second / day on some of the longer missions would likely result in a mission failure due to the nature of orbital mechanics. Is there any mission in our solar system that has entirely failed or had a trajectory deviated from the expected path due to massive (or not so massive) clock drift adding up over time?
Edits/Additional Learning:
For those wondering about clocks, and the drifts that can occur in real-life non-space applications I found a really good resource to explain it in laymans terms. Sort of explains what the every-day objects lose in terms of clock drift such as a wrist watch (20 ppm), it gave me some good scale on the comments.