In the Interplanetary age robots will be as much an essential and commonplace of life as the kitchen sink is to the atomic age. But while being waited upon by his mechanical servants, man will find that he has to do a little serving in return. Mechanics are needed to attend to the most automatic airplanes. Automatic lighthouses must be installed and serviced. This need will not die out. Spaceships will have to find their way through their dark spatial ocean, just as surely any other ship that ever sailed a terrestrial sea. Navigation will be ultra-refined and automated — but it will still be navigation. And it will need the assistance of fixed reference points. Beacons will be needed.
And beacons, no matter how solidly constructed, will occasionally fall into…