This question already has an answer here:
For once, I'm asking for help in identifying a story I've never actually read. Many years ago, I read an essay by Marion Zimmer Bradley in which she talked about a story she wrote, fairly early in her literary career (1950s or early 1960s, maybe?). I'd like to read it, if I knew what it was. (It's been many years, and I don't even recall the title of the book which included this essay.)
I think Bradley indicated that the story was something she'd sold to a magazine; i.e. much shorter than a stand-alone novel would be. It was not a story set in her Darkover universe.
Here's what I remember regarding her statements about the plot of the old story:
The basic premise was that a starship unexpectedly arrived in our solar system, approaching Earth, and it turned out to be an old ship which had been written off as a loss about seventy-five years earlier. When it failed to complete a scheduled trip to a colony world, everyone aboard was presumed dead.
But, as the new crew of the ship told it, the backstory went this way: About seventy-five years earlier, this vessel had something go terribly wrong in the middle of a trip, but somehow managed to make an "emergency landing" (or "crash landing," or whatever) on a fortuitously Earthlike planet which no humans had ever heard of before. I gathered that this new world was nowhere near the place which the ship had originally been headed for, and thus there was no reason to believe that anyone else would come looking for them, in that particular solar system, any time soon.
The survivors of the shipwreck (or whatever had happened) quickly realized that getting their ship fixed up, good as new, was not going to happen soon. Certainly not within the next five or ten years, for instance. They knew, in theory, everything they needed to know in order to make the tools that would make the other tools, etc., to let them finally fix everything that was wrong with the ship . . . but it would take decades of all-out effort to develop the necessary industrial infrastructure before they could put all that theory into practice. (Since they'd also need, in the meantime, to be worrying about such nontrivial problems as growing enough crops to feed everybody, and learning to cope with local flora, fauna, weather patterns, and any other potential hazards.)
This didn't stop them, though! Their new society devoted itself to Starship Repair as the Primary Mission Statement, and after three generations of hard work by everyone who could be spared from other occupations, they finally had their ship all fixed up and safe to fly. Now a crew had brought it back to Earth so they could reestablish contact with the rest of the human race, and find out what interesting developments they had missed. (I presume the rest of Bradley's story then explored the "culture shock" in detail, but I don't think she actually said so in the essay.)
Bradley said that by the time she was finishing up that story, she had realized that this backstory, briefly explained within the text, had the makings of another interesting story all by itself. Because it occurred to her that there must have been a lively political battle, in the months after the damaged ship had touched down, regarding just how this castaway society should arrange its priorities now that it was completely cut off from the rest of human civilization for the foreseeable future.
Bradley felt there must have been a "repair faction" which argued that aside from such basic points as providing food and shelter and medical care for everyone, all extra man-hours of labor should be obsessively focused on those activities which would move them closer to the goal of being able to fix their starship for a voyage back to Earth. And then there must have been a "colonize faction" which would have said roughly the following: "Our engineers say it will take decades to repair this ship . . . and that's the best-case scenario! All sorts of things could happen -- natural disasters, plagues, etc. -- which might invalidate that timetable. If we need to build a healthy society that can sustain itself for the next few generations, then that means it will need to be self-sufficient indefinitely. So why don't we just bite the bullet and admit that our best move is to concentrate on building up a thriving colony, and put the whole idea of 'repair the ship' on the back burner? In a century or two, maybe our descendants will decide that going to all that trouble is a luxury they can afford, now that they've got everything else running smoothly!"
In the story she had written, it was clear that the "repair faction" had won, and thus shaped the common goal of their entire society for the next seventy-five years. But she made a note that someday she might want to go back and write a story about that vigorous debate among the survivors, shortly after the crash-landing, regarding whether or not it was really worth the trouble of devoting their lives, and their children's lives, and so forth, to the 'sacred cause' of fixing the starship as soon as they could. Many years later, she dusted off that idea and combined it with her "Darkover" universe, writing a story set thousands of years before most of her other Darkover stuff, describing what happened when a ship with a few thousand colonists aboard had something go terribly wrong and made an emergency landing on the warmest part of a world suffering from a perpetual Ice Age. That story was published as Darkover Landfall.
So my question is: Which story from earlier in her career was the one she described in that essay; the one that eventually inspired Darkover Landfall? I've taken a look at MZB's Wikipedia page and ISFDB page, and on the latter I can see a list of the non-Darkovan pieces of shorter fiction that she wrote, but I don't see plot summaries, so I have no idea which of them dealt with the basic plot of "seventy-five years after the passengers and crew of a starship had been written off as 'Lost in Space, Presumed Dead,' the starship came back to Earth, crewed by the descendants of the original occupants."