I read this in the 90's, but I believe that it was older; probably 80's, but possibly even as old as the 50's or 60's. I read it in English or Swedish, but I don't remember which of those. It wasn't an incredibly long story, but long enough to be a novel; probably 250-300 pages. I have no memory whatsoever of the cover.
The main plot was that the remnants of an alien civilisation had been found, and there were spacecrafts with pre-programmed destinations. These destinations had not been deciphered, and any crew taking on an assignment had no idea where they'd be going, or even if they'd return alive, but crews were still lining up to go on a mission, be it for fame or fortune.
If I remember correctly, the story is divided between Earth and/or the location where the spacecrafts had been found, and one of the spacecrafts, which had been going for quite some time, and was nearing its point of no return.
This is about all I can remember, and most annoyingly I have no memory at all of how it ended.