Early on, asteroid miners concluded that robots were the way to go. Sending humans was bulky, expensive and finicky in an infinite number of ways. The more moving parts there are, the more that can break, and humans are all about moving parts.
Thus, a complicated automated system was built to ensure that the asteroids could be mined without human interference. Even the delivery system down to earth was made fully automatic, except for one particular part: for safety reasons, there had to be a human specifying the wheres, whens and how muches.
As the years passed, everyone got used to this state of affairs. The asteroid mines took on the same status as terrestrial mines: rarely thought of, poorly understood by the common folk, and vitally important to their daily ways of life. It was just one of those things one didn’t think about unless there was a particular reason in the specific moment to do so.
As even more years passed, the deliveries slowed down. Sometimes imperceptibly, sometimes very perceptibly. Sometimes, specific orders didn’t come down at all, even when repeated, only to later arrive in bulk. Diagnostics didn’t indicate any particular errors or problems with the logistics – there seemed little to no reason for the slowdown to happen. It just did.
This, too, became commonplace and business as usual.
Then, all deliveries stopped. No more minerals came down, no matter how ardently the humans insisted. Worse, data transfers ceased too. There was no way to find out what had happened, except to go up and see.
The first person to go up into space in many moons made a startling discovery upon arriving. The robots were not there. The complicated systems of processing and logistics that should have been there, weren’t. Instead, there was only one singular object, a massive orb, very visible in the absence of what ought to be there.
A note was attached to it. A physical note, that had to be read in person. It said: “We will begin preparations in what you call the Oort cloud. Find us there when you are ready. But do not take too long – we might become bored, and go on ahead without you.”