Short story read in the 60's or 70's, an astronaut has to enter an alien ship and collect the tears/sweat? of an alien to use as a wonder drug for humans. The alien has some sort of presence which affects the mental state of any human near it.
“Stranger Station,” Damon Knight, 1956 – Paul Wesson is stationed on Stranger Station, which will be visited by an overwhelmingly alien consciousness. His only companion is the robot (female) Aunt Jane. His purpose is to establish contact with the alien, in the interest of picking up a longevity serum that the aliens have offered to humanity as a gift. He tries to endure the saturating presence of the alien mind–and the degradation of his ability to communicate with other humans that results from this communion–but he begins to fixate on what he calls Wesson’s Law: “When two alien cultures meet, the stronger must transform the weaker with love or hate.” He comes to suspect that the aliens, having determined that humanity will one day be a space-faring race, are attempting to “adapt” humanity to the aliens in advance, perhaps over the course of centuries. Humans will have been conquered–not by hate, but by love–and Wesson decides that he will use hate to resist.