A Fall of Moondust

“Of course—that's the answer. I should have thought of it before. We've probably been sinking slowly all the time, but this is the first chance we've had to prove it. Still, I'd better report to Mr. Lawrence—it may affect his calculations.”

Pat started to walk toward the front of the cabin; but he never made it.

CHAPTER 25

It had taken Nature a million years to set the trap that had snared Selene and dragged her down into the Sea of Thirst . The second time, she was caught in a trap that she had made herself.

Because her designers had no need to watch every gram of excess weight, or plan for journeys lasting more than a few hours, they had never equipped Selene with those ingenious but unadvertised arrangements whereby spaceships recycle all their water supply. She did not have to conserve her resources in the miserly manner of deep-space vehicles; the small amount of water normally used and produced aboard, she simply dumped.

Over the past five days, several hundred kilos of liquid and vapor had left Selene, to be instantly absorbed by the thirsty dust. Many hours ago, the dust in the immediate neighborhood of the waste vents had become saturated and had turned into mud. Dripping downward through scores of channels, it had honeycombed the surrounding Sea. Silently, patiently, the cruiser had been washing away her own foundations. The gentle nudge of the approaching caisson had done the rest.

Up on the raft, the first intimation of disaster was the flashing of the red warning light on the air purifier, synchronized with the howling of a radio klaxon across all the space-suit wave bands. The howl ceased almost immediately, as the technician in charge punched the cutoff button, but the red light continued to flash.

A glance at the dials was enough to show Lawrence the trouble. The air pipes—both of them—were no longer connected to Selene. The purifier was pumping oxygen into the Sea through one pipe and, worse still, sucking in dust through the other. Lawrence wondered how long it would take to clean out the filters, but wasted no further time upon that thought. He was too busy calling Selene.

There was no answer. He tried all the cruiser's frequencies, without receiving even a whisper of a carrier wave. The Sea of Thirst was as silent to radio as it was to sound.

They're finished, he said to himself; it's all over. It was a near thing, but we just couldn't make it. And all we needed was another hour.

What could have happened? he thought dully. Perhaps the hull had collapsed under the weight of the dust. No—that was very unlikely; the internal air pressure would have prevented that. It must have been another subsidence. He was not sure, but he thought that there had been a slight tremor underfoot. From the beginning he had been aware of this danger, but could see no way of guarding against it. This was a gamble they had all taken, and Selene had lost.

Even as Selene started to fall, something told Pat that this was quite different from the first cave-in. It was much slower, and there were scrunching, squishing noises from outside the hull which, even in that desperate moment, struck Pat as being unlike any sounds that dust could possibly make.

Overhead, the oxygen pipes were tearing loose. They were not sliding out smoothly, for the cruiser was going down stern first, tilting toward the rear. With a crack of splintering Fiberglas, the pipe just ahead of the air-lock galley ripped through the roof and vanished from sight. Immediately, a thick jet of dust sprayed into the cabin, and fanned out in a choking cloud where it hit the floor.

Commodore Hansteen was nearest, and got there first. Tearing off his shirt, he swiftly wadded it into a ball and rammed it into the aperture. The dust spurted in all directions as he struggled to block the flow. He had almost succeeded when the forward pipe ripped loose-and the main lights went out as, for the second time, the cable conduit was wrenched away.

“I'll take it!” shouted Pat. A moment later, also shirtless, he was trying to stem the torrent pouring in through the hole.

He had sailed the Sea of Thirst a hundred times, yet never before had he touched its substance with his naked skin. The gray powder sprayed into his nose and eyes, half choking and wholly blinding him. Though it was as bone dry as the dust from a Pharaoh's tomb—dryer than this, indeed, for it was a million times older than the pyramids—it had a curiously soapy feeling. As he fought against it, Pat found himself thinking: If there is one death worse than being drowned, it's being buried alive.

When the jet weakened to a thin trickle, he knew that he had avoided that fate-for the moment. The pressure produced by fifteen meters of dust, under the low lunar gravity, was not difficult to overcome-though it would have been another story if the holes in the roof had been much larger.