I think the time difference is because NASA is probably alot more cautious than it was 30 years ago. There isn't a nationalistic space race driving them to beat others anymore really, at least not at the level that existed previously. A fatal mistake now causes a great deal of fallout for NASA in today's world.

Stephanie

In every man there is something wherein I may learn of him, and in that I am his pupil.--Ralph Waldo Emerson