The Cave of Night

Gunn, James E. "The Cave of Night." Galaxy February 1955. Collected Some Dreams are Nightmares. New York City: Charles Scribner's Sons, 1974. Translated, and frequently reprinted, including S-F: The Year's Greatest Science-Fiction and Fantasy. Judith Merril, editor. New York City: Dell, 1956.[1][2] Also as a radio drama on X Minus One 1 February 1956.[3][4][5]

Summarized nicely on BestSF website:

[...]The story is a reflection by a journalist, an old friend of the man who has, to the world’s surprise, become the first man in orbit and who, to the world’s horror, is destined to live out his final days in orbit, unable to return.

There’s an elegiac tone as the journalist reflects on how humanity has been brought together by the plight of the astronaut, alone in what he has coined ‘the cave of night’. There is one-way communication with the astronaut, and so humanity can tune in to his broadcasts as the passes over the Earth, the broadcasts in which he becomes increasingly weaker as death beckons.

His death is not in vain, as humanity embraces the need to reach for the stars.

However, it transpires that the journalist’s reflections have been set off by a chance encounter in Times Square some years later… [6]

An encounter with a man he's sure is the astronaut.

Here it's faked, but note "ghost ship" motif, with a twist, for containment in a high-tech sarcophagus in space, a tomb out of technology that was supposed to protect from the dangers of space. Cf. and contrast J. G. Ballard's "The Dead Astronaut," "The Jameson Satellite," MAROONED, 2001: A SPACE ODYSSEY (film), and novel, and (in a very general sense) AD ASTRA and the motif of entering a spacecraft/"ghost ship" with dead bodies and/or related horrors, e.g., EVENT HORIZON.

RDE (with thanks to Andy Duncan), finishing, 24Feb21