OK, I got the one from the research station...
But now I'm having trouble with the mobile merchant.
I had him spawn for the first time in like 30 hours, but he didn't have the artifact. I started re-logging because that resets the stock of merchants, but after at least 50 re-logs still nothing.
Maybe only some of them have it, and a re-log isn't going to change anything? I'v seen a who had the artifact but I didn't have enough credits for it, and I didn't mark the position.