by Hal Clement
Theia was supposed to be nearly motionless. Crius was at standard observing airspeed, which was already rather too close to pipe-stall in the present turbulence. Belvew’s jet nosed up just a trifle as he entered an updraft, his reflexes tried to handle conflicting sets of input, his airspeed dropped further, and both his fires went out.
Mentally, he recovered instantly. Reflexively, he overcontrolled. This did not endanger the aircraft, which had plenty of altitude, or even bother the Waldo suit; this had built-in safety cut-out cut-outs to cover shivering, startle reflexes, and even convulsions. Its wearers were, after all, terminally ill people. The overcontrol was strictly in Belvew’s own body, and everyone in the group, including Xalco, heard his cry of pain.
“What’s wrong, Gene?” the commander cried. The answer came from Status, not the sergeant.
“His right ulna is broken some four centimeters above the elbow. He seems to have forgotten momentarily the background risk of his bone condition.”
“Gene! Can you fly?”
“ ‘Fraid not.”
“Cheru, take Crius.” snapped the commander. “Don’t worry about the pattern if you can’t follow it without practice—the aircraft itself is more important. Status, provide Akagewa with full-detail guidance for the current observing grid until he tells you it’s not needed. Gene, are you out of your suit yet?”
“Yes.”
“Good. Get onto your cot and let Status do what’s needed.”
“Does he know? I haven’t actually broken anything until now. Just expected it.’
“We’ll soon find out. Ginger, what’s your status?”
“Still taxiing, a couple of hundred meters south of the pool, nearly three hundred from the factory. I assume I carry on.” There was no question in her tone at first; then a thought struck her. “Or do you want Cheru to take over here and me to handle Crius? I’ve been in the turbulence already.”
The commander hesitated only a moment. “No,” she decided. “He has plenty of safety altitude if he needs it, and you’ve been down at the factory before, which he hasn’t. Pick up the cans, and at least a dozen labs. You said there were more than that, Status?”
“Yes. Everything previously suggested is ready to load when the jet reaches position. I assume the standing order to look for changes in Oceanus should be followed with Theia’s cameras as she taxis.”
“Right. What are you doing about Gene’s arm?”
“The bone ends are set and the elbow immobilized. There are few data on what to expect in the knitting process with his ailment, but it will certainly be many days before he can use a suit either for flying or environmental protection. I will maintain even closer watch than before on his blood calcium concentration and bone analysis. Do you have further suggestions?”
“Not right now.” She did not bother to add that anyone who had an idea which seemed promising, reasonable, or even slightly relevant should announce it; Status as well as the living crew would take that for granted. She went back to the basic problem.
“How do the chemistries of the three pools compare with each other and with any others you have on file?”
“All resemble each other in being essentially gels with apparently monovinyl alcohol as the dispersing agent. I have no basic data which would have let us predict that this compound would be so stable even at Titan’s temperature. The most up-to-date bonding data I have suggest that the activation energy for its conversion to water and acetylyne should be low enough to make the reaction almost explosively rapid even here. We are of course in a temperature range where tunneling effects greatly complicate rate calculations, but ordinary theory still does not seem to apply.”
“I suppose,” Yakama interjected at this point, “that this could be all to the good if humanity survives and we have nothing to do but unravel the universe’s pattern. I admit it complicates the survival problem, if this project is really a key part of it.”
Even Belvew chuckled at the words, and Maria briefly but uselessly pitied the computer, which went on, “Subject to countermanding, I am isolating the sample under study in the mausoleum, though the behavior of those still in the commander’s quarters at normal life temperature suggests that trouble is not likely.”
Humor and pity were replaced promptly by other feelings. Foreseeing biological contamination by Titanian samples was routine; not foreseeing possible explosion risk was more than embarrassing.
“When a situation is thermodynamically unstable, as when there is a lot of free oxygen around in contact with reducers, there’s always one reasonable explanation,” Yakama pointed out.
“I’m glad you didn’t say only one. The general word ‘life’, without more specific additions like ‘photosynthesis’, isn’t much better than ‘supernatural’ as an explanation,” the commander reproved him tactfully but firmly. “Have you any specifics?”
“Not yet, but I think something’s cooking. I want to get more comparisons.”
“Status is watching.”
“I think this may be a bit abstract for mere statistics—but give me anything you spot, Status.”
“Of course,” the nonhuman voice responded. This phrase meant explicitly that the command was superfluous because it was already in effect, but Seichi did not apologize. There wasn’t time, actually, as the computer went on, “there is a discrepancy heavily masked by turbulence effects but gradually becoming plain, between Crius’ power settings and airspeed. Move slowly, Sergeant Belvew, you have other bones at risk, and there is no obvious immediate danger to the aircraft.”
Belvew may have stopped moving, but began speaking.
“The pipes picked up something in the lake, remember? Something that burned out later. Show us the wings. You can override the programming that keeps the plane itself off the screens, can’t you? You can watch all the camera fields.”
“Yes.”
The Aitoff in Belvew’s quarters did not change, but smaller screens suddenly displayed much of the wings and stabilizers of Crius for examination. Maria quietly requested the same information, and both examined the areas carefully. Not even Belvew felt certain of what it was he saw, but he said thoughtfully, “Status, do you have camera viewpoints enough to get solid images of these fields?”
“Yes. I have them, but doubt that you could perceive anything significant without my setting in exaggerations which would destroy the image meaning for you.”
“But there are changes.”
“Yes.”
“Describe them if you can’t show me.”
“Irregular areas on the wings carry a coating, never more than a fifth of a millimeter thick and much less in most places, of a varnish-like material which would be colorless to human eyes, though if absorbs strongly in some infra-red bands. On that basis as well as the background events it is probably organic.”
Yakama smiled, knowing no one could see him.
“This is just on the wings?” he cut in. “Not on stabilizers?”
“Right.”
“And the stabilizers were not immersed in the lake, but the wings were.” This was not a question, and not even Belvew answered it. He did not remain silent, of course.
“Commander, I suggest we break off this grid run, slow the jet down enough to make it safe, and play with the wing camber. It would nice to know whether this stuff is frozen and will crack off, or—is different.”
Maria, silently thankful that Belvew had not given the suggestion as an order to Akagewa, asked the latter, “Cheru, did you hear that?”
“Yes, Maria.”
“How about it? Practical? You’re high enough.”
“I’m still in heavy—turbulence, and wouldn’t—like to slow—down much farther. Let—me finish this bar—of the grid and get—out into quiet air first.”
“Right.” Maria indulged in no superfluous nod; she, too, was at home in the Waldo suits.
“And Status!” added Belvew, “keep close track of the thickness of that stuff on the wings, starting right n
ow. Don’t wait until Cheru starts trying to stretch it.”
“I am recording and will make a general report of any change.”
Maria did not let the next few minutes go to waste.
“Seichi, how is your chemistry going? Or did this new item distract you?”
“The analyses are going well, and the event has distracted me. I want a chance to analyze whatever is on Crius’ wings. Can that be done without landing her near a lab?”
“I don’t see how,” the commander replied slowly and thoughtfully. “Any suggestions, anyone?” A silent pause ensued. “All right. Cheru, when you get out into quiet air, head for the factory—no, the lake is closer. Tell me when you’re clear and I’ll give you a heading. You haven’t made a landing before; do you want to swap with Ginger?”
“I don’t think so, unless someone thinks this stuff on the wings will cause problems I can’t foresee. If it’s just going to affect wing stall, I can handle that—land a little hot. Gene?”
“Probably no trouble. At transonic speeds even tiny changes in airfoil shape can be tricky, but not this time. You’ll be doing a lot more to the wing shape yourself as you make the landing.”
“That’s what I thought. Thanks.”
All remembered, but no one mentioned, the Oceanus’ last landing. Status would give warning now of hydrocarbon ice on the wings, but neither the computer nor anyone else would know what other warning might now be appropriate. Akagewa began to plan in detail just what flight tests he would make once out in quiet air, but did not bother to discuss them with Belvew; his own piloting experience might not be as great as the sergeant’s, but he was sure he knew enough relevant physics. Belvew’s higher rank seemed irrelevant just now; like everyone else in the group Akagewa was more scientist than soldier.
Belvew himself was a little uncertain about what he should be doing. He was by rights an observer, specifically an aircraft handler though like the rest he could put his skills and mind to almost anything. He had, however, come over the months to think of himself as THE pilot, and his present inability to fly was, to put it mildly, frustrating. It even left him feeling embarrassed about giving flying advice.
This was actually a healthy attitude; Cheru Akagewa could make stall tests, and Ginger Xalco could load and take off again, just as well without his looking over their shoulders. Perhaps even better, since they were actually handling the controls.
The question of what was coating Crius’ wings was up to Seichi and Status. Gene himself was not a chemist—for that matter, neither was Seichi, though he had inherited that aspect of Arthur Goodell’s work. No one there was actually a chemist, or a physicist, or an astronomer, or a geologist, or a biologist; they were all generally well informed people, but the knowledge was mostly in Status’ memory. The living minds were there to think and decide.
Even those of the mere observers. Belvew smiled at that thought. Then, after another two or three minutes’ brooding, he told Status to abstract at a level somewhere between “franchise” and “specialist” and to begin feeding him biochemistry.
Ginger looked a little uneasily at the remains of Oceanus as she slid past, but did not allow the memory of Belvew’s landing misfortune to distract her seriously. Loading items from the factory was straightforward but required care; one had to get close enough for the loading handlers to reach the jet, but not too close.
Wings could not be allowed to damage themselves against ground structures, and getting into a position which could not be escaped without exposing the factory to rocket exhaust would be highly embarrassing. The factory could, of course, be replanted, and a new version might in the long run be an improvement, but if the wasted time meant that they were all dead before their job was done the incident would still have to be counted a net loss.
She inched the aircraft slowly into position, wincing slightly as the tank gages forced themselves on her vision, and signalled the factory to start loading. A tube promptly reached out from a low extension of the main structure, passed over and along her right wing, and approached the fuselage. She relaxed slightly as the proper hatch opened to accept it, and her instruments showed that the seismic cans were settling into the right magazine. She felt even better as this filled and labs began to come aboard.
She was almost completely happy when the tube withdrew and left her free to fire up once more. Almost, because the mass gages were still looking at her. There were also chunks of fallen ice from the western cliff to be avoided. She felt quite proud of managing this without sending exhaust anywhere near the factory, but the gages still wore an increasingly more reproachful expression.
She considered the wind, and decided that even a slightly downwind takeoff would use less mass than taxiing to a better spot. She swung around to the southwest, carefully lined up with no visible ice fragments directly ahead and within several hundred meters, and pumped liquid into the arcs. She noticed on her Aitoff an ice boulder behind Theia caught in the exhaust and shattered to flying fragments, wished briefly that this could have happened early enough to warn Barn Inger, and really relaxed as her keels left Titan’s surface. Looking for a thunderhead was routine.
Cheru was not particularly tense as Lake Carver came into sight ahead. It would of course be his first live landing, but he had followed through on many others. His recent tests indicated that the stuff on his wings would not affect the procedure.
He was coming in from the south; he didn’t want either to overshoot and end in the lake, get involved with Belvew’s Pool, or have the job complicated by even the tiny crosswinds Titan might furnish. He was taking a very small chance of ending his landing slide on the hill—he was aiming to stop between it and the lake—but felt sure he could taxi out of danger in time even if the patch were in a sticky or polymer-eating mood.
He assumed incorrectly that Belvew would be watching, and felt relieved when Crius slid to a stop within a few meters of the spot he had intended. The hydrocarbon lake was a little over ten meters to its left, the pool/hill a little farther to the right, and the three surviving labs in clear sight twenty meters or so ahead. He had known before starting the approach that the fourth had now been completely absorbed by, or submerged in, the whatever-it-was. Akagewa was developing a sympathy for Seichi’s view.
“Shall I save mass by letting a lab come here, or taxi closer to them?” he asked, rather expecting Belvew to answer.
“We have more mass than time. Taxi over,” came the commander’s voice. He obeyed, without actually being casual about his tank content.
“That’s about as close as I can get without overshooting,” he finally reported. “Seichi, can that thing climb up on my wing from there?”
“Definitely not. We’ve faced that before. Even the wing roots are a couple of meters above ground, and no one ever figured these things might have to climb access ladders.”
“Does that mean someone will have go down in person? We should have thought of this earlier.”
“I did. I think we can manage, but I should have spoken up before you got so close. Let me walk the labs a little way ahead—sorry about your tanks—to keep them out of your wash, and then taxi a little farther. Slant toward the pool so your starboard keel gets a little way uphill, but keep an eye out so the left wing tip doesn’t actually dig into the ground.”
“Do you think the slope is steep enough to bring it that close?”
“Status says so.”
“And that I have juice enough to get off after all this?”
“With a safety factor better than four, as experience goes so far, yes. Relax, Cheru. If you don’t bet you can’t win.”
This aphorism had become an accepted code in the group for use when a colleague was becoming too cautious, so Akagewa lighted his engines without further remark. Two or three minutes later Crius’ left wing tip was half a centimeter from the ground and Yakama happily directing one of the labs toward it. The device could not walk or roll up really steep heights, but irregular surfaces had been fore
seen. The pro tem chemist maneuvered it onto the airfoil and worked it, with Status’ help, over to a patch of coating which the human beings could not see.
It seemed unwise to use the sampling scrapers on the wing surface, but the labs were equipped to mop as well as dig. Within two minutes, Yakama had ten samples from as many different spots on the left wing and had started the lab back toward the tip, five meters out from the fuselage.
By the time it got there, the end of the wing was nearly three centimeters from the ground; the right keel was sinking. Neither chemist nor pilot would have known, but Status was on the job and gave a warning which caused Seichi to send his equipment tumbling off the wing and travelling as fast as it could toward the lake. Akagewa, by effort of will, kept his engines cold until the chemist reported the lab at the lake’s edge and presumably as safe as possible. He had not yet risked another lab in the liquid, and was not going to take the chance with this one until the new specimens were analyzed—no one wanted to repeat the whole risky and time-consuming process.
On Seichi’s word, however, he lit his fires and gave Crius all the thrust he dared. For a moment Cheru held his breath as the right keel stuck, but then the craft lunged forward. For another moment the chemist held his as the lab’s thermometer suddenly climbed. His heart might have suffered as well had he been watching the jet’s dials and recognized the slight swerve caused by the pool’s brief grip on the keel, which momentarily sent the rocket blast directly at the lab. The instrument started back down in less than a second, however, and in a few more Cheru reported his charge to be airborne.
There was at the moment no thunderhead visible over the lake, a fact which Maria noted as needing explanation sooner or later, but the pilot circled slowly as he climbed, spotted a likely mass source a dozen kilometers away, and headed toward it. General attention shifted from aircraft to analytical instruments.
“Any phosphorus?” asked Maria, recalling Goodell’s readings of weeks before.
“More likely C-N-O.” Belvew’s return to the conversation was less surprising than his choice of subject.
