How we cite our quotes: (Chapter.Paragraph) Note that chapters aren't numbered, so need to be numbered manually, 1 to 14.
Quote #1
For a fraction of a second, my throat tightened and I thought longingly of the Prometheus and its strict discipline; the memory of an existence which suddenly seemed a happy one, now gone forever. (1.67)
Kelvin has barely landed on Solaris, and he's already nostalgic for the lost past of being on a spaceship and having people tell him what to do. This is not a forward-looking, no-regrets kind of guy.
Quote #2
But evidently the dead do not change; they remain eternally young. (5.5)
This could be a comment on the afterlife, but it could also be a comment on how memory works by freezing people in time. And you could also say that memory has frozen Kelvin himself in time; he can't get past Rheya's memory (and we know this is true, because the magic ocean told us so).
Quote #3
I leaned over her and turned back the short sleeve of her dress. There, just above her vaccination scar, was a red dot, the mark of a hypodermic needle. I was not really surprised, but my heart gave a lurch. (5.35)
This is a creepy bit of business. Rheya has the mark of the needle that she used to kill herself. Kelvin's memory of her is also the memory of her death; the two can't be separated out.