Auriga's cabin set it dancing on the screen. For this reason, everyone aboard the ship was motionless, and all nonessential machinery had been switched off.
Chief Engineer Lawrence was standing on the edge of the raft, his space-suited figure braced against the small crane that had been swung over the side. Hanging from the jib was a large concrete cylinder, open at both ends - the first section of the tube that was now being lowered into the dust.
"After a lot of thought," said Lawrence for the benefit of that distant camera, but, above all, for the benefit of the men and women fifteen meters beneath him, "we've decided that this is the best way to tackle the problem. This cylinder is called a caisson" - he pronounced it "kasoon" - "and it will sink easily under its own weight. The sharp lower edge will cut through the dust like a knife through butter.
"We have enough sections to reach the cruiser. When we've made contact, and the tube is sealed at the bottom - its pressure against the roof will ensure that - we'll start scooping out the dust. As soon as that's done, we'll have an open shaft, like a small well, right down to Selene.
"That will be half the battle, but only half. Then we'll have to connect the shaft to one of our pressurized igloos, so that when we cut through the cruiser's roof there's no loss of air. But I think - I hope - that these are fairly straightforward problems."
He paused for a minute, wondering if he should touch on any of the other details that made this operation so much trickier than it looked. Then he decided not to; those who understood could see with their own eyes, and the others would not be interested, or would think he was boasting. This blaze of publicity (about half a billion people were watching, so the Tourist Commissioner had reported) did not worry him so long as things went well. But if they did not .. ..
He raised his arm and signaled to the crane operator.
"Lower away!"
Slowly, the cylinder settled into the dust until its full fourmeter length had vanished, except for a narrow ring just protruding above the surface. It had gone down smoothly and easily. Lawrence hoped that the remaining sections would be equally obliging.
One of the engineers was carefully going along the rim of the caisson with a spirit level, to check that it was sinking vertically. Presently he gave the thumbs-up signal, which Lawrence acknowledged in the same manner. There had been a time when, like any regular spacehog, he could carry out an extended and fairly technical conversation by sign-language alone. This was an essential skill of the trade, for radio sometimes failed and there were occasions when one did not wish to clutter up the limited number of channels available.
"Ready for Number Two!" he said.
This would be tricky. The first section had to be held rigid while the second was bolted to it without altering the alignment. One really needed two cranes for this job, but a framework of I-beams, supported a few centimeters above the surface of the dust, could carry the load when the crane was otherwise engaged.
No mistakes now, for God's sake! he breathed silently. Number-two section swung off the sledge that had brought it from Port Roris, and three of the technicians manhandled it into the vertical. This was the sort of job where the distinction between weight and mass was vital. That swinging cylinder weighed relatively little, but its momentum was the same as it would be on Earth, and it could pulp a man if it managed to trap him on one of those sluggish oscillations. And that was something else peculiar to the Moon - the slow-motion movement of this suspended mass. In this gravity, a pendulum took two-and-a-half times as long to complete its cycle as it would on Earth. This was something that never looked quite right, except to a man who had been born here.
Now the second section was upended and mated to the first one. They were clamped together, and once again Lawrence gave the order to lower away.
The resistance of the dust was increasing, but the caisson continued to sink smoothly under its own weight.
"Eight meters gone," said Lawrence. "That means we're just past the halfway mark. Number-three section coming up."
After this, there would only be one more, though Lawrence had provided a spare section, just in case. He