Half Life (10 page)

Inger had weighed privately, without consulting Status again, the importance of this job against the likelihood of his becoming helplessly anemic before it was done, and had decided that a modest delay in the descent was all right.

Satisfied at last, he drifted into the pilot’s “coffin” and spent another twenty minutes testing his suit controls. Finally, using the spring launcher, which saved reaction mass, he kicked the vessel free and allowed it to drift slowly away from the roughly spherical structure of welded ice fragments.

He could see both Saturn and Sun, at screen coordinates which meant that they were in nearly opposite directions. The lumpy assemblage of ring chunks from which he had come blocked out nearly half the sky and much of Titan, while the satellite in turn occulted a large fraction of the remaining starry blackness.

Their almost spherical shapes were distorted grotesquely by the equal-area projection, but this bothered neither Inger nor the others sharing his view. He allowed
Crius
to drift until the station filled less than a tenth of the screen’s area, spun her on a lateral axis until the pipes pointed “forward” along the station’s orbit, made sure she was in rocket mode, and vaporized a small amount of reaction mass.

This craft had not yet made any descents, and her tanks contained only a small amount of water remaining from the original journey and construction work. Even the little he now used up committed
Crius
to atmosphere after two minutes of falling away from the station, but the man wasted no time or thought on the fact that he, too, must descend.

Rather more than an hour later and a third of the way around Titan he felt the touch of drag. He had used a little more water than absolutely necessary. Orbital velocity, less than two kilometers a second, was too small to cause a serious heating problem, and before making a full half circle from the point where he had left the mass of ice—which was still in view: it had not fallen very much behind him during the descent—he was using wings and aerodynamic controls, and had uncapped the pipes into ramjet mode.

The rest of the flight was uneventful; it was a new adventure for the aircraft, but not for Barn. Finding an adequate cloud, and using it to fill the tanks with liquid hydrocarbon, had long been routine. Clearing the tanks first of the traces of unused water was not, but he well knew, as he had known on his first landing and Major Xalco had known on hers, what ice crystals at liquid methane temperature could do to
Crius’s
pumps. He took care of the matter early enough so that even Belvew, letting his attention wander slightly from the jet he himself was operating a quarter of the way around the satellite, felt no temptation toward outside-the-coffin driving.

Finding the factory and landing beside it were also routine; Inger had been the first to take one of the ramjets to the surface. The fact that he had not been physically aboard that time was unimportant; the waldo suits worked either in direct-connection or remote modes, the latter suffering only signal-travel delay of a few milliseconds.

Crius
slid to a stop a couple of hundred meters from the factory. Inger had not checked for wing “ice,” but he landed hot as a precaution. He completed the power-down check of the aircraft and the Titan environment check of his suit, and emerged. There should be no need to report the fact even to his partner; everyone was presumably watching carefully.

Even Belvew, who was having a minor problem of his own.

Theia
was high enough in the smog layer for Saturn and its nearly edge-on rings to show dimly on her screen, though they were rising and setting too fast for comfort. Gene ignored the sight as best he could.

Circling Titan’s south pole at one hundred meters per second and increasing the radius of the circle by half a kilometer each time around took no attention, of course; that sort of thing could be set up in advance. The satellite’s rotation axis’s being a couple of degrees from perpendicular to its orbit plane was merely background information, though it was responsible for Saturn’s present peekaboo behavior. The bothersome item which did demand attention was a steady altitude loss by his aircraft.

It was not frightening. The ground was tens of kilometers down and the descent mere centimeters per minute, but it was puzzling. It was also annoying; correcting the altitude manually every minute was a nuisance, while setting the automatic controls to do it might hide important data in unrecorded corrections. Not even Status’s log covered everything.

There was also the matter of self-respect; the sergeant wanted to explain the phenomenon himself before Status, whom he preferred at times to think of as Nursemaid, made him feel foolish again. His rank might imply a mere observer rather than a theorist, but he considered himself perfectly qualified to think.

Thrust and attack angle were correct, and corresponded to the airspeed. Energy consumption matched the mass of atmosphere being piped, the thrust indicated by the ramjet mounting sensors, and the weight of the aircraft. There were no lake thermals at this height and latitude. There must be some obvious factor he hadn’t—

There was. The calm voice of Status, committed to reporting changes of background whenever they reached a certain level without regard to their probability of danger, made itself heard.

“There is a slow general descent of the polar air mass covered so far on this air circulation run. Symmetry suggests it to be quite precisely centered on the pole itself. There must be poleward flow above
Theia
’s present altitude, and equatorward below. Repetition of the present flight pattern at a larger number of levels than originally planned appears in order. When the entire volume has been vector-sampled I suggest comparison with the total upward flow over the lakes.”

Belvew could think of only one response which might restore his morale.

“How does the air density match norm for this height? It should be greater if there’s such a huge downdraft.”

“It is. Qualitatively this could explain the effect.”

“And quantitatively?”

“Unanswerable until the vector analysis is more nearly complete. More data will be needed for that.”

Another thought restored Belvew’s self-esteem even further, and he voiced it before the analyzer beat him again.

“Is there enough more smog in the air to account for the higher density?”

A human voice cut in. Even now it sounded slightly amused, though no one knew why.

“Wouldn’t more polymer drop the density? It’s made from the surrounding gases, and would use them up as it’s produced.”

“It would drop volume, Maria. The mass would still be there and contributing to pressure, I’d say; and that would start inflow, which would carry solid and liquid particles from a distance—” The debate was interrupted.

“The inflow wouldn’t be in. It would be around. There’s Coriolis force even with a sixteen-day rotation and small planet size, and no surface friction fifty kilos up.” The new voice was Arthur Goodall’s, and no one added anything for a moment; the old fellow had an annoying habit of being right, aside from being officially their commander. Belvew was about to take a chance on mentioning the minuteness of the Coriolis effect, but was saved by Status’s voice.

Goodall himself, in his sealed quarters two hundred meters from Belvew’s and closest of all to the station’s spin axis, paid no attention to what the computer said. He had known as the words left his mouth that his reasoning was sloppy. It was getting constantly harder for him to think coherently, and more and more of his time was being wasted wondering how long he could be useful at all to the project.

The pain kept getting worse, and distraction from it more difficult.

Of course he couldn’t work all the time, or even all the time he was awake. Rest and relaxation were essential, but relaxation which would hold the attention firmly was, he had found, almost a contradiction in terms. Reading was better than watching shows, he knew. He suspected that this was because it was a less passive activity, but he had never raised the question publicly and had therefore never been obliged to produce a challenging hypothesis. He had been told long ago that the discomfort of SAS—synapse amplification syndrome—was less severe than that of shingles, but he had never learned how his informant knew. If anyone had ever suffered from both it must have been at different times for the effects to be distinguishable, and whichever had been experienced later would have been remembered as being worse.

Arthur Goodall had the normal, reasonable mistrust of data dependent solely on human memory, and a chain of human memories was far worse. Besides, he knew of no reliable technique for actually measuring pain, though he had heard of units intended for the purpose.

He knew all he wanted to about SAS. Unlike shingles, it affected every square centimeter of his skin at one time or another, but caused no external markings. Like shingles and chicken pox, it was produced by a virus, one which had been identified and mapped within weeks of the first recognition of the syndrome.

It differed from the shingles/chicken pox agent in only four amino acids at specific points plus one bundle, perhaps originally an independent organism, which rendered it unresponsive to both natural and engineered human immune systems. The four acids were few enough to be explained by natural mutation, but numerous enough to make human tampering a reasonable suspicion; the bundle was natural, but might have joined the virus either with or without human assistance. It made no difference to Goodall whether he should be blaming nature’s indifference or human malice; the molecular engineers who now made up most of the medical profession had not yet worked out either a nonlethal contravirus or a straight chemical treatment. Sam Donabed, the only remaining medical specialist of the expedition, occasionally discussed the matter with colleagues on Earth when his other duties permitted, but neither they nor he had come up with any helpful procedure.

Sam was officially only a lieutenant colonel and Goodall could reasonably have lost patience and told the doctor to leave him alone; but neither the commander nor any of the others thought of him as a military type, scientist or otherwise. His rank was irrelevant; he was a doctor, and rational people still tended to follow doctors’ recommendations even with the full knowledge that they amounted to experiments with no two identical subjects. Human beings vary in more than hair color.

Besides, losing patience would have been ungentlemanly, immature, and rude, and at Goodall’s age he didn’t want to risk his reputation for maturity.

Doctors had, of course, a lot of work to do on other ailments, and there were only a few hundred cases of SAS at a time to worry about, so there was no use in Goodall’s complaining about being at the short end of a triage situation. Most people now alive shared that distinction.

With the pain growing ever worse, what he really wanted now was not a cure—not exactly. He wanted an opportunity. He had even worked out in some detail just what sort of opportunity. It should, he felt, occur
somewhere
on Titan. The plan needed only one of Maria Collos’s gel pools, not too far from a lake, and isolated in some way from the rest of the big moon’s surface.

There were a few impact scars on the ever-growing map he was developing on his own without consulting Maria. Crater walls might provide the isolation, though all mapped so far appeared badly weathered or nearly buried. This might seem surprising, since there appeared to be no high winds in Titan’s heavy atmosphere, and methane rain should be a far weaker erosive agent than water, but on the other hand both had presumably had several billion years to do their work.

At least two of the craters on Maria Collos’s less specialized maps did contain small lakes. This was hopeful, and the maps were still being revised and extended, partly in the standard course of planned operations and partly in Goodall’s personal, private files. He wondered more and more frequently how long he could keep that up. It was this sort of solid, detailed work that could best turn his attention from pain, sometimes for hours at a time, but the distraction by his body was getting harder and harder to fight.

The chances of finding an ideal site for his slowly developing personal project were decreasing, though he was not admitting this yet to himself. Titan’s equatorial regions had now been well mapped, and his personal travel problems made the rest of the satellite much less suitable. He still had hopes, however. He might be short on time, but not yet on patience.

He turned his attention back to the display of Belvew’s—more correctly Theia’s—Mollweide screen, and resumed looking for ground images which might bear detailed study. Even polar areas
might
be usable, although much less accessible.

But watching quickly became boring, and boredom gave the pain access to his attention. He wrenched his mind back to the Station, the best place to find the immediate, serious work which he needed. No immediate work? What should he read?

Belvew was in no trouble, and the new atmospheric data seemed trivial, however interesting. There was one bit of chemistry to be rechecked, but it would be a while yet before any more data could come from Maria’s tar pools, gel pools, prebiotic sites, or whatever they were.

To Goodall, the mistake about methanol’s being part of the gel had been interesting and somewhat embarrassing. He had of course corrected it with Status, but without calling the attention of his living colleagues. He did not intend to tell them until someone asked him why there had been no methanol found in the dock to which Ginger Xalco had brought
Theia
days before. Not having to explain the matter had been pure luck; Louis Mastro, bless his rapidly deteriorating heart, had been loudly and emphatically interested in what seemed to have been ammonia crystals in the ice specimen Ginger had also collected. The dear fellow kept hoping aloud that another piece of the “geode” specimen might be brought up to orbit.

One could see why, of course; ammonia crystals growing in an ice cavity could be very informative about details of Titan’s history, as calcite and quartz geodes were about Earth’s…