The "Riding Rockets" book by shuttle astronaut Mike Mullane goes into this a bit. It's very hard on the families. Rocket launches aren't that safe. And the b

The "Riding Rockets" book by shuttle astronaut Mike Mullane goes into this a bit. It's very hard on the families. Rocket launches aren't that safe. And the best time to retire is right after you get back, because that's the furthest time from your next flight. The longer you wait, the more you get caught up in the next one and just want to make it through that one.