by Hal Clement
“Another stall?”
“Just a bump. If I’d really been riding this machine—I’d—show ‘em the accelerometer records, Status.”
Exclamations like her own sounded in other human voices. All but one of the group were experienced enough, and identified well enough with their craft while flying, to “feel” the jerks shown by the instruments. The gaps in the pilot’s sentences were understandable to all.
“That’s close to red line,” Belvew worried aloud. “No one expected real turbulence here.”
“If you’d hit that at four or five times standard speed we’d be looking back at your wings,” Peter Martucci remarked uneasily. “Shouldn’t you slow down?”
“And risk having—all the lift go out—from under me?”
“You have plenty of altitude.”
“And that’s the—way I want it. How much longer—should I hold this—run, Status? I don’t—suppose the original timing means—anything any more. Is—there any trouble compensating for this—bucking? I’ll slow down if—the readings really need it.”
“There is no problem with the readings. Aircraft safety is still paramount.”
Silence, except for an occasional annoyed mutter from the acting pilot, ensued for some minutes. Maria had been tempted briefly to offer a suggestion—which would really have been a command—that Belvew take over the piloting; but the jet seemed in no real danger, and morale was important even, or perhaps especially, among a dying crew. She couldn’t compromise by taking the controls herself, for two reasons. She was no better a flyer than Xalco at the best of times and everyone knew it, and this was not the best of times.
The Waldo suits which operated the aircraft from thousands of kilometers were complex devices requiring input from many parts of the wearer’s body including toes, chins, and noses. Some potential group members on Earth long before had been rejected for poor facial control. The possibility that someone might need to fly with a missing right hand had not been foreseen, and in the fortnight since its loss no one in the Station had been able to think of a way to compensate for it.
She looked across her cubicle—actually a rather luxurious and extremely well equipped living space and laboratory—at the two tanks where most of her specimen from Arthur’s Pool reposed. It had seemed harmless enough to scoop up, in a glove designed to keep her hand from turning to glass at a surrounding temperature of ninety Kelvins and in a reasonably conductive atmosphere, a sample of the viscous matter in which Goodell had died. Xalco’s worrisome sticking in a similar pool had proven merely frightening, with no resulting damage.
Maria’s inability to clear her glove of the stuff during free fall up to the station had been merely a nuisance; Belvew had done the piloting. Embarrassing experience with their late commander had taught them to install bypass systems in the two remaining jets so they could be flown remotely even when someone was actually aboard.
Back in her quarters, however, the stubbornness of the sample had graduated from an annoyance to a problem; and when she realized that part of her glove had been dissolved and the stuff was starting to work on her hand, she had to declare an emergency situation. Of course all the individual quarters were equipped with remote-control surgical equipment, and a laser amputation had been a minor job—well within even Status’ competence. Even while it was going on, Maria had been almost more interested in another matter; she had joined with gusto, and seemingly full attention, the discussion over why the sample had failed to be inactivated by a temperature rise of over two hundred Kelvins. An egg starting at a normal three hundred ten, would have been much more than hard boiled at, say, the melting point of aluminum—a comparable ratio in temperature increase. Seichi Yakama was already talking as though the stuff were alive, but no one else went that far. Alien suit-penetrating and flesh-eating monsters seemed at least as unlikely to sober and rather conservative scientists as the alien kidnappers of UFO mythology. Besides, no one could really believe that a major goal of their mission—establishing that either life or prebiotic chemistry existed on Titan—had been achieved in less than a year and with so many of the original group still alive.
Things had never been that simple even in saber-tooth tiger days.
But Maria Collos could no longer fly, and the stuff in the tanks—one containing mostly the sheared-off forearm and gauntlet of her suit plus adhesions, the other the more personal material which had been extracted from it—was probably relevant to the problem even if not an answer. It was certainly interesting, not only to the victim. An obvious first experiment was under way; a scrap from the second tank’s contents was taped to the hand of one of the mausoleum’s residents, under remote observation to see what the stuff would do to human tissue at Titanian temperatures.
Maria had of course made the proper gesture, offering to resign the command she had so recently inherited from Goodell, but no one else wanted the job. The responsibility was often a distraction from more interesting work, and the crew unanimously, promptly, and firmly agreed that a theorist didn’t need two hands. Maria wished fleetingly that she had had as good a chance to argue with her late predecessor, but was accepting the situation. At least, the bunch of argumentative day dreamers had now committed themselves to following her—recommendations.
And the daydreams, more formally called hypotheses, were still being produced, luckily. She wouldn’t have to stimulate any imaginations. Martucci’s voice was relieving her of that worry right now.
“Y’know, Ginger, that point of Gene’s about equinox may have something. Just think of it as eclipse season. I know the sun’s a long way off, but a quick change of heat input over a whole hemisphere as Titan ducks into Saturn’s shadow might very well do something.”
Not even Belvew really spoke for some seconds, though many voices muttered at spot calculators.
“It’s worth checking,” Maria agreed slowly. “Intuitively, I’d say the input was very small, as you suggest, and if there is any effect it’d be lost in chaos. It takes Titan about half an hour to move its own diameter along its orbit, and except at the middle of the eclipse season it would take even longer to get completely covered or uncovered by Saturn’s shadow. Longest possible eclipse at mid-season, which we haven’t reached yet, is only about ten and a half hours. Could be a respectable amount of heat at that—Pete, you and Seichi think of some ways to word useful questions to Status on that one, bearing the chaotic possibility in mind.” She knew that everyone else would try to beat the assigned pair to the idea draw, but that would do no harm.
“The air’s quieting down, I think,” Xalco finally reported. “It’s been over an—hour. That’s quite a storm cell for Titan, if it was a storm cell.”
“It was not.” Status’ tone showed no change, but its firmness was taken for granted by everyone. “There was nothing cyclonic about its wind patterns, and there seems to have been more descending than ascending current area, though that cannot be certain; you traced only a single, rather irregular line across the region. The cause is not clear. I am making the obvious correlations which have been suggested as routine, but any others you want will have to be added by living imaginations. Nothing significant has appeared so far, and with the volume of data now involved it will take at least ten more minutes to make the remaining routine comparisons.”
“Please include eclipse data in them,” Maria replied.
“Done. I had already interpreted Corporal Martucci’s words as a suggestion. Only the fact that eclipse season and large-area turbulence started within a Titan orbit of each other, and in that order, is obvious. Both starting times are too recent for causal relationship either way to be reliably inferred.”
“What next?” asked Ginger. “There are a few more seismic lines to lay out, aren’t there? I mean the originally planned ones, not the stuff we’ve had to improvise around the new volcanoes.”
“You’ll need to restock on cans first,” Belvew spoke before the robot managed to do so. “The extra patterns cut into the rese
rves pretty deeply.”
“I know. There should be plenty at the factory—Status, you didn’t stop manufacture when the stocks we originally planned were finished, did you?”
“Yes, but I reset the unit for more after the change in operations was implemented. There will be a full load waiting when you reach the factory.”
“Then I’d better start back there now. Heading, Maria or somebody?”
“Do you still have labs aboard?” cut in Yakama.
“Sure. Why?”
“I’d like very much to make some comparisons between Arthur’s Pool, the one by the factory, and the one at Lake Carver where Gene set down and started to sink a few weeks ago. We dropped a lab there at the time, but it got blown into the lake when he found he was sinking and took off in such a hurry. There are a couple of units still working in Settlement Crater and lots at the factory site where the—where you’re going anyway, but I’d give a lot to be able to cross-check all three places where any of our stuff has touched Titan’s surface physically. D’you suppose you could drop another lab there by Lake Carver before you settle down at the factory, Ginger?”
“I don’t see why not. Wait a minute, though—we know we’d better not drop it in the lake, since we couldn’t hear the first one after it went in, and we know the ground there is pretty hard. Wouldn’t I have to land to get a lab down intact?”
“Gene landed, and you dropped labs from flight during Maria’s hike, and they stood it all right—”
“They landed in snow!”
“About four centimeters deep, as I recall.”
“That can make a big difference, especially under Titan gravity. But aren’t there any snow patches reasonably close to Carver? The labs can travel, after all.”
“I take it you’d rather not make an extra landing.”
“Is that criticism?”
“I’ll do it if you like,” Belvew cut in. Maria played this one safely, too.
“Ginger can do it if it needs to be done. I agree with the importance of having labs there, if only to get an analysis of that lake; we never found out why we couldn’t read from the unit blown into it—it could have been depth or composition of the lake or blast damage to the lab itself. Go ahead down, Ginger—but do check the area for snow patches first.”
“There were none nearby at that time,” Status reminded them. “All the ice we have seen has been massive, except the dust recently being produced from the volcanic vents.”
“I’ll look anyway. Heading, please?” Ginger relaxed; at least this should be a more comfortable ride. It was.
There was indeed no snow, and relatively little surface ice; Lake Carver was on Titan’s darker trailing hemisphere. Ginger was not, as she had tacitly admitted, eager to land, but had no intention of handing Belvew the responsibility. She made all reasonable delays, looking unsuccessfully for nearby snow patches, doing a careful wind run and even topping off her mass tanks at a nearby thunderhead—she had used rocket mode once or twice in the turbulence—but it seemed clear that dropping a lab even at minimum safe flying speed and altitude would probably only wreck the equipment. Even if the device remained in shape to heal itself, that would certainly take much longer than a landing.
The pilot rather hoped that Maria would decide to risk a drop anyway, but the commander felt that the balance favored making the landing. Ginger spotted Belvew’s Pool with the lake in the background, lined up Theia toward it, and began her approach.
She had detected no wind and observed no turbulence, so there was plenty of time to adjust letdown rate. She should touch just at the bottom of the near side of the gentle slope—she wondered suddenly why neither of the other named “pools” had shown such a bulge, but put the question firmly aside; this was no time for theoretical work. She was just above pipe stall speed—closer than Belvew had gone before shifting to rocket, she recalled; but he’d been enjoying a small head wind. Not that that made any difference with airspeed. Fifty meters above ground, six hundred from touchdown—
She closed the intakes and began to draw from Theia’s mass tanks. Her bare scalps—her nickname dated from many years before she had qualified for Titan, and even before her infection—she could feel trickling with perspiration, and she was fleetingly glad of her isolation. Belvew, his Aitoff and other instruments copying hers, hoped his relief at the mode shift was inaudible. Someone else gave a grunt which might have been approval; the change to rockets had barely shown on the accelerometers.
Thirty meters up and three hundred to go—descent had slowed a little, but now she had to watch for imminent wing stall. She was overshooting a little. Nose and power both down just a trifle, but watch that airspeed. The bulge of the pool now hid the lake. She should still land on this side, but might not stop sliding before the top. Still overshooting—was a tail wind picking up? If an updraft were starting to grow over the lake, that would be its effect. The thunderhead where she had juiced up was well behind her. No way to check without aborting the landing and going up to make another wind run, and she wasn’t going through all that again.
She couldn’t touch now less than halfway up the near slope. The air must be moving. No matter, she could still—but yes, it did matter; beyond the top the slope was downward, and that was when even Belvew—cancel that “even”, blast you, Xalco—had had trouble. Not much, but some.
Her keels touched before Theia reached the top, but not very much before. There was a swelling black cloud at either side of her Aitoff, just as Gene had had, and she cut thrust the instant her meters showed the ground drag.
Not soon enough. The jet ballooned, probably only a few millimeters, but failed to touch again until it was halfway down the slope. It wasn’t much of a slope and the aircraft didn’t have much wing area, but Titan doesn’t have much gravity. Then she was firmly down and slowing rapidly.
Not as rapidly as the now very visible lake was approaching, however. There was a thunderhead growing over it, she thought in surprisingly detached fashion as the jet crossed the shoreline.
“Well, we had to find out sometime.” At least the remark hadn’t come from Belvew, and there was no way for anyone to tell how frantically the commander had striven to beat the sergeant to it. “What’s the lake density, Status? You have the Theia’s mass, shape, and volume parameters and can read how deeply she’s floating.”
“A little higher than expected for a ninety-ten methane-ethane mixture at that temperature, but not outside reasonable variations in such a mixture. If the Major will eject a laboratory we can—”
“Not ‘til you’re ashore!” Belvew did get that exclamation in first. “We know the lab won’t float, and we can’t hear its output from under the surface.”
“Strictly speaking, we don’t know it won’t float,” the commander pointed out. “The density of lab and lake certainly aren’t very different. We never really looked for the other on the surface, and it might have been damaged by the jetwash that blew it away. However, I agree it would be best to get ashore first. I’d suggest very, very gentle thrust in rocket mode, Ginger.”
“And expect it to be pretty bumpy even then,” pointed out Belvew. “The liquid will boil around the arcs and get blasted out the pipes. That’ll stop as the arc clears itself and resume when juice sloshes in again. It’ll be like pouring from a narrow-necked bottle, I’ll bet.”
“I’ll bet.” That was encouraging. So not even Belvew was completely certain what would happen with the pipes submerged and flooded. The point had been overlooked during design of the aircraft. Xalco wasn’t sure whether Gene’s uncertainty was a relief or an added worry.
The arc controls involved her hands rather than knees or toes, fortunately, but she activated them with even more caution than she had used in the landing.
The jerking wasn’t bad—Theia was massive and the lake offered plenty of resistance to motion—but the sergeant had been essentially right. She bumped away from the shore, experimented with cambering the vertical stabilizer in its ordina
ry steering use and found it ineffective. The obvious alternative was to cut power to one engine until Theia’s nose pointed back toward shore and hill. Then, even more slowly and carefully, she began to retrace her path.
“Hadn’t you better tank up?” asked Martucci. “You used juice to land, and will use more getting ashore.” Ginger didn’t answer directly, but followed the sensible suggestion.
“Status, check how much mass I take aboard, how far it sinks me, and cross-check the lake’s density,” she said. It took her a moment to remember the appropriate controls; all previous tank-ups had been made in flight from airscoops, and opening an inappropriate valve now seemed unlikely to be habit-forming. Again she fought off the temptation to let Belvew take over.
The mass change was small and the rise in fluid line perceptible only to instruments. Status reported a small change in the computed density and claimed it exceeded reasonable measurement error, but the collective human judgement dismissed the difference as unimportant. It was certainly minute. Theia resumed the bumpy drive shoreward.
She was close in when the keels touched; the slope of the lake bottom appeared steeper than that of Belvew’s Pool, now renamed by some of the party unofficially as Belvew’s Hill. Without consulting anyone, Xalco gently eased more energy into the arcs.
Theia bumped further inshore as though being tapped from behind by a giant putter on a wet green, and her bow began slowly to rise. Then forward motion and hammering stopped for fully a second. Before the pilot could decide what to do, even before Belvew could offer advice, there was a loud “thud!” and a stronger forward jerk. Both repeated themselves in a fraction of a second, but less violently. Motion and sound ceased again; then Belvew gave a cry of warning.
It was unneeded; the pilot had also seen the panel light and reacted properly, feeding mass from her tanks to both arcs. Another blast from the pipes, much more violent in terms of acceleration but much less noisy than the others, sent the jet completely ashore.
