Is Jack London's The Star Rover science fiction or biography?

Star Rover is speculative fiction, more Fantasy than Science Fiction now, but at the time things like astral projection, hypnosis, mesmerism, et cetera were all considered things that science would someday figure out how to quantify.

There is no reason to think that the story is biographical. There was a movie a few years ago that claimed to be based on the true story Star Rover came from, but that was just artistic license for the movie.