Half Life (17 page)

Even when tired. Maria hadn’t used to get this tired. Her cancer seemed to be in remission, and nanotech devices were handling the sugar control it had long ago destroyed, but she could detect her own deterioration just the same. She knew all about her own ailment, of course, and the knowledge widened the mental crack which was letting the what’s-the-use feelings leak in; but she had caulking for that leak.

The sealant was a perfectly rational thought: If we quit, we
won’t
find out. Ever. If saving humanity is indeed worth any trouble, then quitting is certainly a mistake; if it isn’t and the fact finally becomes clear, one can always quit later. After the futility is solidly demonstrated, of course.

In the meantime, finding things out was
fun
.

She was certainly being useful right now, though not finding out very much. She was alone on Titan’s surface.
Cries
, which had brought her down, was back in service, doing shuttle flights to and from the station and other work of its own rather than waiting for her. There was so much to be done down here, so much which had to be useful, and so much needed to be done everywhere else to support the useful activities.

Much had already been done since Arthur Goodall’s final experiment. A hundred meters north from the mouth of the tunnel where Maria stood was a quarry in a cliff face, with a power saw and hundreds of ice fragments lying near it. The work had been done so far by powered hand tools; programming a factory for construction of blocks of ice had been surprisingly difficult.

Many of the pieces were square-cut bars of varying lengths and thicknesses; many more were fragments of such bars. It had taken much effort, and more time than had been hoped, to learn enough about the structural qualities of ice at local temperature to let Status calculate how deeply the surface base would have to be dug or how big a structure could be made of the blocks; but now the excavation had started.

During the testing, as usual, more questions had been raised than answered. The top of the low cliff containing the quarry had shown layering: three clear and obvious sequences of the dark smog-tar which had settled over so much of Titan, alternating with a few centimeters of white material which was probably compacted ice dust but which there had not been time to analyze yet.

Unless, of course, Louis Mastro or Carla lePing had filed a report which Maria had not yet had time to hear. They had, she remembered, been almost as insistent about investigating similar layering at the top of the cliff near Factory One; but that had been inaccessible to anything but cameras.

Crius
, since landing her at Settlement Crater, had already restocked its mass tanks and was in orbit back to the station, probably being flown by Gene.
Theia
was in atmosphere dropping seismic cans or checking air circulation or something. Her pilot could have been almost anyone at the moment, and anyone else the next.
Oceanus—well
, that hadn’t been her fault. In not too many hours Seichi Yakama, still physically able to fly and work in spite of advanced Hansen’s III syndrome, would relieve her on the ground here at Settlement, and
Crius
, after taking her back to the station to rest and restock her suit, would descend once more and resume adding details to Status’s image of the satellite. Routine went on, in other words.

It had been Status’s decision, actually. The deaths of Goodall and Inger had brought the personnel count down to nineteen, which the data handler apparently considered a critical value in spite of the low relevance of statistics. He—it—now insisted that spending time ferrying people back and forth between station and surface was wasteful of their chief resource, time, as well as dangerous. As long as any surface work by human beings was necessary, it would be better in the long run to construct a base below and transfer everyone down for good. The extra commuting needed while construction lasted should be offset by time and personnel saved later.

When Maria and others had doubted this, Status had shown detailed calculations. These seemed to be correct, but only a bare majority of the surviving researchers had accepted them. They were emotionally negative, like those about the population crisis in the days when human population had still been rising.

Showing mathematically how little time it would take to transform the planet into human flesh at whatever growth rate was then current had never had much effect, at least where it was most needed.

The Saturn group of educated nonspecialists was presumably better qualified than most to judge whether a silly conclusion was due to faulty math or to faulty assumptions, but its members still had the normal human difficulty believing anything which would make for personal inconvenience. They also had the normal human skill at finding excuses for the attitude, even under semimilitary discipline.

Status had won the vote, however, and there was no point standing there brooding. After all, resting wouldn’t really help Maria’s fatigue, which was not caused by work, and delay would only lengthen the time being used—wasted?—on this construction. She moved back toward the tunnel mouth.

In front of her as she faced east was a vertical cliff some fifteen meters high. To the south its top descended gradually, merging with the crater floor about half a kilometer away and about equally far from the impact crater’s central lake. South of this point lay the area where the jets had been landing.

Northward, past the quarry where the test bars had been cut, the scarp seemed to grow higher, but how far this continued only Status knew so far.

This human ignorance was embarrassing to Maria. She had been responsible for the original mapping from orbit. A fault like this, which presumably postdated the crater itself, should have been
noticed
by herself, not just recorded, if it had been, by a machine. As it was, not even the pilots landing in the crater had seen it. Arthur Goodall had not reported it. Only after the decision to move down, when the ringwall and its floor had been mapped more carefully even than Goodall had done, had it shown, and even then no one had bothered to trace it farther north than the quarry site.

Of course, pilot attention would have been taken up by other matters like landing, but still…

No one believed yet that it could have formed in the last few weeks. Possibly no one wanted to believe it. Maria could easily imagine how Arthur, who had searched so long for his ideal experiment site, would have reacted to the idea.

Most of the cliff top showed the light rusty brown edge of the smog deposit that, mixed with varying amounts of ice dust, covered so much of Titan. The ground at its foot, however, was bare ice. It must have taken time for some weathering agent to wash away the dark sediment on the west side of the fault, and something more mysterious to do so without also clearing the high side. A few crusty deposits like candle drippings, perhaps dissolved from the top of the cliff by rain and precipitated again at the foot by evaporation, were all that marred the level surface near tunnel mouth and quarry.

Even these should have taken a respectable time to form. Titan’s surface was clearly being reworked by erosion and tectonics, but there seemed no reason yet to suppose that this was happening any faster than on Earth. If anything, the absence of liquid water suggested the contrary.

Maria would have liked to see what the fault had done to the north rim of the crater, but she firmly rejected the temptation to go and look. There should, after all, be a nicely detailed answer already in the unexamined data above, but this was not the time for talk. Status
might
“know” in a sense; but the processor was neither omniscient nor imaginative. It would come up with correlations it had been told, explicitly or sometimes even implicitly, to seek, but never with theories.

It could only criticize these.

On the other hand, if Maria herself seemed likely to be too far from the landing site when the jet came back, so that she might not reach orbit while her suit supplies lasted, the computer
would
foresee that and firmly recommend return before she got anywhere near the rim. Suits could not yet be recharged on the surface, and Status was specifically responsible for all aspects of human safety.

None of this was conscious thought for Maria at the moment, just background knowledge. Status information, in fact.

Just north of one of the small, presumably alluvial tar “fans” was the entrance to the tunnel she was digging. It was about two meters high, with a five-centimeter sill of piled ice sand across the bottom, and about as wide, since equipment as well as suited people would have to get in. It was dug in the clear, nearly pure low-pressure ice—ice I—which formed the lower two-thirds of the cliff under the sediment layers. The latter was thinner than average here; one might use that to date the impact which had formed this crater—no, the sediment was gone from the cliff foot, and there seemed no way even to guess how much the stuff on top had been affected by the same erosion. Or why there was a difference—never mind that now, Collos.

Back to work. Research and fun could come later. She stepped across the clear ice and the rill of liquid methane running southward along the foot of the scarp—it had been raining ever since her arrival—picked up the chipper, and turned it on. It hummed obediently, so she descended the hundred and twenty meters of completed tunnel and pressed it against the end wall. Its iridium-armored teeth resumed shaving and swallowing ice, and blowing the resulting powder toward the tunnel mouth behind her. The group had learned; this machine had a double head and counterrotating blades. It did not try to spin her in either direction no matter how hard she pressed it against the wall.

She was getting more skillful in its use, too. It could only exhaust straight back, but she was now able to aim the heads most of the time so that “straight back” not only missed her suit but blew the dust much of the way to the tunnel mouth. She only had to pause every ten or fifteen minutes to clear her exit path. Her relief would bring a newly grown blower to handle that job, she had been told; most educated adults could still do improvisational programming on equipment seeds. The new factory now growing near the central lake nine hundred meters to the south even had locatable roots, a quality lacking in its predecessor. In two or three weeks it should also have produced a remotely controllable tunneler, and Maria and the others could get back to their proper, planned overseeing work.

That was if the iridium brought from Earth held out, of course. Cannibalizing labs for tools was a dubious idea at best, when one considered long-term planning.

She was angling the tunnel downward, and already had nearly twenty meters of ice and sediment overhead. Human beings under Titanian gravity, she had noticed, seemed not to feel much fear of cave-ins, a comforting if unrealistic attitude. This confidence had started to change for her recently, she had noticed, as ground tremors became more frequent, but she still did her best to enjoy it. Details of the planned base had not yet been completely worked out, since planning took so much more time than execution, but it would certainly have to be deep enough to be walled and ceiled by clear, seamless ice even if they decided to change to Titanian air pressure inside.

The fallen smog layer was about as strong as sand except where methane rains had caused it to crust.

There it was more like sugar exposed to varying humidity—sturdier, but still not a reliable ceiling, even in local gravity and with balanced pressures.

The need for the downward slope had therefore been obvious. That for the sill at the tunnel mouth had not. The stream along the cliff face was intermittent, and had been dry when the digging started. Now there was methane sloshing around Maria’s feet as she worked. Blowing this outside with the chipper had seemed an obvious solution when the liquid first trickled in, but the drops wouldn’t fly as far as the ice chips in the heavy air. They also ran back downhill before she could reach the area where they had landed in order to blow them still farther. At least the ice dust waited for her.

She had taken care of some of the problem by digging a sump a few meters back, but this, unfortunately, had meant plastering some of the ceiling with an ice-methane mud which seemed always to choose the moment she was underneath to drop by handfuls onto her helmet. Water even on Titan did not bond closely with hydrocarbons, but the digger was an effective blender.

Maria, even in a philosophical mood, still spent some of her work time distracted by curiosity over which items of this rapidly growing crop of trivia might turn out to be lethal. She was not alone in this, though only she was in the tunnel.

She did what she could about the lack of company, reporting every action and its result to the station and to Status, though she put more faith in human imagination than in data-based calculations as a source of warning.

“More vibration!” she called suddenly. Belvew replied.

“Could it be your chipper getting out of balance, or biting deeper with one head than the other?” GO6 alternative hypotheses were a moral imperative, not just on Titan; being too sure too soon—the Aarn Munro syndrome, as some classicist had long ago named it—had proved a fruitful source of trouble throughout human history.

She turned off the machine as the most obvious way to test this one.

“Right, I guess, but—no, there it is again.” She reactivated the digger and pressed it once more against the wall in front of her. The quivering stopped briefly, then resumed. “It’s not that.”

“Local quake? Titan still has plenty of tectonics, we know.” This time it was Pete Martucci.

“Wouldn’t the seismometers be telling us?”

“Not necessarily,” Status’s calm voice answered. “Seismic events have occurred often since the first can line began reporting, and seem to be regular Titan phenomena. However, the outer ice I layer does not carry waves as quickly as silicate rock. None of the can lines is close enough to Settlement Crater for an epicenter under that point to be recorded promptly. I advise you leave the tunnel until that idea can be checked, Commander Collos.”