This was the first hard SF novel I read, oh so many years ago. The original short story didn't have the personalities, but I think they add to this story. To people who expected to be in contact with earth when they landed, what are the effects of passing thousands of years, or millions, or the death of the earth itself? I thought the ending was a little quick and a little convenient, which brings it down to 4 star for me. Definitely enjoyed rereading this, though!