by Hal Clement
“I might, but not if it were more than a dozen or two meters away. About getting up . . .” the commander’s voice trailed off.
“You can jump two meters—or are you worn out again?” Belvew made no specific reference to Maria’s ailment, though he was of course aware of it.
“I’m afraid that’s not it. This white coating has been stiffening up my joints, for quite a while now, enough to make walking difficult. I’ll try, but I’m not sure I can jump at all.” There was silence from the Station while she tried, reported failure, and tried again.
“I can’t get up half a meter. Check the maps you have so far. Is there any place which looks as though it might be anything but a vertical cliff? Surely you can’t just push a prism of ice up like this, especially if the ice is effectively rock, without some irregular cracking somewhere.”
Again Status took unintended parts of the remark literally. “Not enough is known about the mechanical properties of ice at these temperatures. Remember how Sergeant Inger was taken unaware by its expansion coefficient. Our only pictures of this new feature cover the minutes since it formed. There are several irregularities around its perimeter, on all six faces including the north one where you presumably are. If you can still walk, I advise you do so in either direction along the scarp.”
“If—” Belvew choked off the exclamation. Then, “I’m setting down. Go left, Maria. It’s clearest to the east. You can walk, I hope.”
“Oh, yes. But we must check the pool, and should check the lake, and they’re up top.”
The jet’s roar suddenly became audible over the sound of escaping vapor, and faded again. Belvew continued as though the commander hadn’t spoken.
“I can’t land up there.”
“Why not?” came the usual multiple voices.
“The area is just barely wide enough for a landing at all, approaching just above wing-stall. At that speed the turbulence from the fog blast—I felt it with the gages a hundred meters up—as I cross the edge would wreck the plane unless, by pure luck, updrafts under both wings were exactly equal. I know I’m safe up here, but once is more than enough.”
“I can get down again after I get up,” Maria replied calmly. “Don’t try to land anywhere until I’m through here. That’s an order.”
“How do you mean that word through?” Belvew let the question out, and immediately regretted it. Maria had tact as well as firmness, however.
“I think I see at least two ways of getting up,” she said, still calmly. “At the other fault, the updraft tossed me off the ground; this one seems a lot stronger. With luck, Bernoulli effect will keep me inside the stream until I get to the top.”
“And maybe longer. What will you do hanging a couple of meters out of reach of the ground?” A little to her surprise, the voice was Seichi’s, not Gene’s. She had to hesitate only a moment before answering.
“I’m a lot bigger than the lab, and can do things about my overall shape. I won’t be out of control.”
“What’s your other idea?” asked Belvew predictably.
“Build a ramp. The ‘snow’ is three or four centimeters deep.”
“How much snow will she have to move, Status?”
“It depends on the angle of repose of the particles, another unknown quantity. Its behavior under Earth conditions is irrelevant; it is sand or dust here, if it actually is ice. Assuming a twenty degree repose angle, the volume would be approximately thirty-two cubic meters. If the commander’s estimate of snow depth is correct and general, it would require all the snow within a distance of some sixteen meters of the climbing point. The material is apparently available, but the time required to move it without tools may be excessive. This ignores the problem of building against the updraft at the inner side of the ramp. The commander has about eighteen point two hours, extrapolating from the last two hours’ consumption, to suit emergency status.”
Long before this sentence was finished, Maria had approached the whistling crevice at the base of the scarp. By the time Martucci had pointed out that she could accumulate a large volume quite rapidly by the snowball-rolling technique, and Seichi had reminded him that snow did not self-weld readily at ninety Kelvins, she had leaned for the first time as closely as she could against the smooth ice face and been hurled backward with satisfying violence.
By the time she had tried again, backing against the wall and pushing as hard as she could with her legs, which was not very hard under Titanian traction conditions, Chem had pointed out that the stuff had at least stuck to the commander’s armor, so maybe snowballing would work after all.
Before the argument got any farther, Maria interrupted. “What I can see of my armor is now nearly clear of its white coating. I can move quite freely. Something in the vapor stream got rid of it, I guess,” she concluded.
“It was hot enough to melt it, and blow the liquid away,” Belvew proposed at once.
“The dust particles sand-blasted you clear,” Seishi came back at once with the obligatory counter-hypothesis.
“If they stuck in the first place because of altered surface tension, they’d have just added to the coating this time. It has to be temperature.”
“That couldn’t have been why they stuck. Surface tension won’t hold any size water drop liquid down at ninety-K.”
Maria again ended the debate without suggesting this was not the time for it; she was interested in the reason herself, but had not needed any of the recent reminders about her suit’s depletion or what work had to be done.
“I’m jumping—now!” There was a silence of two or three seconds.
“Make it? asked Belvew.
“Not quite. High enough, but I bounced off the fan of vapor—it’s all right, I was able to land on my feet. It must have been a matter of armor shape; I should have been pulled into the stream.”
“Pushed.” This was Martucci.
“Don’t be a purist. Here I go again—I’m in, this time. Bouncing around, as someone suggested, a meter or so above the top of the scarp. I can regulate my height with arms and legs—there. Now—blast, up again. I’m oscillating. I can vary the rate and amplitude by reaching—there. Resonance. I’m out, and on the right side. Oops—there’s a breeze trying to push me back into the current—”
“I told you so,” said Martucci. Maria ignored this.
“No traction to speak of—wait, I’m all right—I’m away from it now. The wind is only within a couple of meters of the edge. You were right, Gene; don’t try to land here. The visibility isn’t very good, either. I’m heading right to look for the pool.”
“It’s only about seventy meters,” Martucci informed her. “You can see me?”
“Sure. There’s contrast again, now your whitewash is off. Head along the edge to your right ‘til I tell you to stop, then turn straight away from it and hike about thirty meters. Not too close to the edge; remember that Bernoulli wind.”
“Is the seeing worse than outside?” asked Belvew. “That west wind is covering the hexagon with fog, or dust, or whatever’s blowing up on that side. Is the stuff blowing along the surface, or overhead?”
“Surface or both, I’m afraid. I can see the rim, but not the pool yet.”
“It’s time to turn,” called Martucci. “Right angle, away from the edge. Tell us when you see the pool, so we can give Gene a real measure of the visibility.”
There was silence for a few seconds.
“I think it’s there—yes, I can see its near edge.”
“Sixteen meters,” muttered one of the watchers.
“The color is funny, a lot redder than any I’ve seen. Certainly redder than the one you got stuck in, Ginger. I can see four of the labs, now; I hope they’re working. I’m right at the edge, now. The color isn’t the same all over; some of it, away from the rim, is almost black, and there are a few spots where the snow seems to be sticking. They’re all several meters from the edge, and none of the labs is anywhere near one; shall I get a sample to bring up?”
“You got loose.”
“From stuff that looked different. Don’t take any chances. Pick up one of the labs and toss it onto the white, but keep your feet out of trouble.”
Maria followed this suggestion, and scored a center hit the first time. She was getting used to the gravity, evidently.
“I won’t step on it, but I’m going to get a sample from the edge to take up. We can do more with it in the Station than the labs can manage.”
“Be careful!”
“Relax, Sergeant. I said I wouldn’t step in it.” There was silence for over a minute, a very tense one for the watchers in the Station; instrument resolution wasn’t quite good enough to show what parts of Maria’s suit were actually above the pool, especially when another shock tossed her upward. She landed feet down about half as meter onto the stuff but was off before it managed to stick to her boots—if this variety were going to. She did not report all the details to the others.
“I have a chunk,” she called at last. “It’s gooey, like the stuff that caught you, Ginger. I don’t have anything to put it in, but I can carry it in one hand—the piece is about fist size. I’ll leave the digger. I don’t know why I carried it this far. Now, Gene, I’m willing to make you happy. I’ll pass up the lake. Where can you land?”
“Closer than I thought. If I go into the wind, which isn’t really fast enough to matter, I can touch down half a kilometer from the corner at the east end of your edge—you’re at the west, about the same distance from it. Go back to the edge, turn right, start hiking, and please don’t let any new cliffs form in the next few minutes. I’ll skid to about three hundred meters of the corner, and can drive closer on rockets. Jump through the updraft when you hear I’m down. Don’t get down any sooner; if I have to abort and land somewhere else, it’ll be easier to cross the hexagon than go around it. I’m lining up now—slowing down near pipe stall—letting down slowly—I don’t want to get too low until I cross the crater rim.” There was half a minute of silence. “Over the rim. Rocket mode. Height one fifty—one hundred—” the pilot ceased reporting for several endless seconds. “Touched down, sliding as usual. I’m coming into the fog and can’t see very far ahead, but I made the approach a little north of your edge so there’ll be no trouble if I slide too far. There; stopped. Pete, how far am I from Maria? Should I push a bit closer?”
“You can go another hundred meters. Maria, you still have a way to go. Don’t hurry; getting picked up again by the updraft would waste time.”
“Your suit has seventeen point six hours.”
At least, walking was now easy.
“Your suit has seventeen point four hours.”
At last Martucci’s voice. “You’re there. Commander. Go ahead and jump. Try to land so you don’t pick up another coat of paint.”
“The updraft will have more to say about that than I, but here goes. I’m backing off—picking up speed as fast as I can—thank goodness ice isn’t slippery here—THERE! I’m through, but I’m somersaulting—don’t know how I’ll land—got a fair kick upward—coming down—feet first but leaning forward—good; I caught myself with one hand. Pete. I can’t see the jet. How far and which way?”
“One hundred thirty meters, the way you were travelling when you jumped—about forty degrees north of east. Just keep going, as fast as you can.”
“That’s not very fast. The ground’s shaking again.”
“So the accelerometers are saying,” Belvew agreed. “Status, record their readings. They should help make sense of the can reports.” Maria silently gave thanks that he could work as well as worry.
“I see Theia,” she called as the dark bulk loomed in front of her. “Good guiding, Pete. Twenty meters—the fog’s thinner—ten—I’m there. Climbing, aboard—hatch open—inside, sealed up.”
“You want to fly out yourself?” asked Gene.
“No. You keep it.” The commander let it be assumed that she was acknowledging Belvew’s piloting skill; she was not going to mention any other troubles while worry might interfere with his flying.
“Fine. I don’t know what’s ahead well enough to risk a westward takeoff. It’ll have to be downwind. No matter, with that wind speed.” The right engine roared, and Theia slid slowly forward, turning gradually to the left until her nose pointed back along the landing approach.
“Ready, Boss?”
“When you want.”
Both pipes thundered and Maria gratefully felt the acceleration which Gene could only read from his instruments far above. Her own screen showed little detail, though it was set at a wavelength which gave several hundred meters of fog penetration, and she watched the center of the Aitoff ellipse tensely.
The ground was fairly smooth, but with bumps to let her know by their cessation when Theia was airborne. Her tension remained; the crater rim was not very far ahead, she knew. How far had the run up to flying speed taken?
She remembered the flight instruments, and glanced at them.
Less than two kilometers, and it was over three to the rim—good—altitude fifty meters—a hundred—a hundred twenty as the wall flashed into view below the center of her screen. At the same moment she felt, just barely, the slight jolt as Belvew cut the reaction mass flow and let ramjet take over.
“Want to fly now, Maria?” he asked.
“No, you’d better keep it. I’m not sure I can.”
“Why not? Fatigue again?”
“A little, but that’s not the problem. I can’t get this sample of the pool off my right glove. Do you think it would be smart to warm this compartment up?”
“Commander!” Martucci cut in excitedly. “We wondered why you were tossed upward from the low side of those faults. It’s just friction! The rising side dragged the other with it for a moment! Ice isn’t slippery there, remember!”
Belvew, speechless for once, gave his attention to Theia.
SIMILE
Hal Clement has been writing Science Fiction for more than forty years. His Novel, Mission of Gravity is considered to be one of the best, if not the best, Hard Science Fiction ever written.
No one, not even Major Xalco herself, thought of her as being in her own quarantine section within meters of everyone else, though they all knew the fact. For all practical matters except vulnerability she was driving Theia, seven hundred kilometers below and a third of the way around Titan’s globe from the station’s present orbital position, trying to hold the jet at standard observation true airspeed of one hundred meters per second.
Even after an Earthly year the illusion of actually being in the aircraft tended to take over at unfortunate moments. The fact that occasionally the pilot was really on board probably made matters worse. The optimists who had believed at first that random reality reminders from Status would eventually cease to be needed had finally given up the hope.
Ginger Xalco had never been an optimist. She was in fact known as one of the first to comment whenever things seemed to be getting worse, and her voice now was practically a snarl.
“I don’t—know what would—constitute a P-K catastrophe on this—silly moon.” She got the words out in spasms, when some of her attention could wander briefly from piloting. Theia at the moment was not so much flying as being blown around, four kilometers above the smog-stained ice of the surface. Turbulence was not new; it had been met by all the pilots in reasonable places, mostly within and under the thunderheads which commonly grew in the week-long daytime over Titan’s numerous lakes. Horizontal winds of more than a meter or two a second, however, originally rare, were now routine. So was the seismic—actually new volcanic—activity which had ended the first attempt to set up a surface base and was now racking four other areas on Titan’s surface.
One of these was centered less than a dozen kilometers from the first factory. This might, of course, be coincidence; no one but a pessimist could feel sure ei
ther way.
Gene Belvew, whose non-commissioned rank made him officially a mere observer rather than a theorist, seldom let that fact keep him quiet. He answered Ginger’s rhetorical remark with a more literal question. “Why should we assume this is something catastrophic? We’ve been here only a fraction of a Saturn year, and we’re near the equinox. That’s a stormy period on Earth.”
Ginger’s attention was not too occupied to permit a retort.
“You mean some parts—of Earth, where—the sun—makes a lot of—difference. And since when—were volcanoes seasonal—whoops!”
“Trouble?” Major Collos, informally Maria, legally group commander, cut in instantly.
“Downdraft. I overcorrected—and had a pipe—stall. No danger—plenty of altitude—there. Fired up again. Status, that’ll put a—kink in my line. Allow for it.”
“Checked,” came the robot’s deliberately unmistakable voice. “It may be relevant that the increasing turbulence of your last few dozen kilometers shows a rough correlation with increasing methane content of the air.”
“Probably is,” Belvew’s voice sounded thoughtful. “Most of the thermals I’ve ever run into are over lakes, where the evaporation would drop the air density—”
“And drop the—temperature too. I thought we’d—agreed not to call them ‘thermals’. Or are—you just reminding us gently—that you were a pilot long—before this affair started and can’t—bury old professional knowledge?”
Maria, nearly certain that this charge was justified, changed the subject. “Are there lakes below you, Ginger? I don’t see anything special on my mapping stuff, and haven’t been following your Aitoff screen. What part of the spectrum are you using?”
“Long enough waves to see the ground—I’m below most of the smog anyway. There are four—lakes I can see from here, but none right—under me and none specially big. There’s no obvious reason—for extra methane—wow!”
