How we cite our quotes: All quotations are from Alien.
Quote #1
KANE: I feel dead.
PARKER: Anybody ever tell you you look dead, man?
Spoiler alert! That's some pretty serious foreshadowing right there, and let's not forget that the hypersleep tubes look suspiciously like coffins. It's all just the subtle ways the film is letting your brain know that it'll be encountering death here.
Quote #2
DALLAS: Anything else?
ASH: Yes. There's rock—lava base. Deep cold, well below the line.
Everything about the planetoid seems tuned to be lethal to humans: the atmosphere, the air, the temperature, the ground, you name it. Without a spacesuit, it's insta-death.
Quote #3
DALLAS: He could die in 24 hours. Open the hatch.
RIPLEY: Listen to me. If we break quarantine, we could all die.
LAMBERT: Would you open the goddamn hatch? We have to get him inside!
RIPLEY: No. I can't do that, and if you were in my position, you'd do the same.
It's the old Spock conundrum; do the needs of the many outweigh the needs of the few? Ripley seems to think yes while Dallas is going with a no. We know Ripley is right, but we have the advantage of having seen how the movie comes out.