Classic Fiction

by Hal Clement

  THE END of the contest was, in one way, something of an anticlimax. Imbriano had thought of nothing brilliant; Frake and Detzel had made no contribution; and Ingersoll had shown no sign of giving up and when the whole situation was changed—instantly and without warning.

  The doctor had suffered his closest shave yet, just barely escaping the charging treads, and had ducked around the front end of the train to its right side. Ingersoll made his closest turn thus far, cutting a trifle left to get his single attached trailer clear and then swinging around so as almost to graze the front of the motionless one. There was no collision; Detzel had his lights on the scene at the moment, and he, Frake, and Imbriano himself were all certain that nothing solid touched the stranded vehicle. Imbriano, who was actually touching it at the time, was sure he would have felt the impact.

  Nevertheless, something happened. It was not an explosion—at least, not exactly so. The tank which had been filled with “snow” opened almost deliberately, and sprayed over everything in front of it a furiously boiling, dense, misty vapor which glowed a bright blue-green, dazzling even against the background of the brilliantly-sunlit mountains. It covered Ingersoll’s cab completely; and blinded by the featureless glare, he brought his machine to a stop. That was enough for Detzel, who had been waiting for any sort of opportunity. He hurled his own tractor toward the other, angled it across Ingersoll’s front so that the geologist was cramped between Detzel’s tractor and the detached trailers. His own trailer, still attached, prevented him from backing without making a “cut” which his front end was not free to do. Ingersoll, or rather his machine, was pinned completely. Getting the man himself, at odds of three to one with the one under a steering wheel, was not too difficult.

  “I HOPE they can straighten him out on Earth,” Imbriano said soberly to Kinchen a dozen hours later. “He’s way beyond me. He had made a real discovery there in Newton—he must have made it on the first trip, to have planned the second as he did. Instead of reporting it, and getting all the credit he seems to have wanted so, badly, he pulls this incredibly complex trick. It’s like a kid who’s daydreamed all the details of a party he’s going to attend, and flies into a tantrum when the facts don’t follow his imagined program, I think Milt planned the plant discovery before we ever left Earth—he must have, to have brought the lichens with him—and wasn’t quick enough on the uptake to throw the game aside when he made the real discovery. Life moved too fast for him.

  “Of course, it moved too fast for me, too. I still can’t see what happened to his tank back there. As far as I can see, he was perfectly right about the snow still being soil and there not being enough energy to do anything.”

  “You surprise me,” grunted Kinchen.

  “Why?” asked the doctor.

  “Your admitting that you don’t know.” Imbriano flushed, started an angry retort, then calmed down.

  “Don’t rub it in, Chief. I feel enough of a heel already. I suppose it was that which helped push Milt as far as he went. I don’t say I’ll stop because habits are hard to break, but I’ll try. What did happen to the snow, though?”

  “I don’t know, either, the astronomer replied. “It will take analysis to make sure. I think, though, that your suggestion about the snow collecting from space—nebular material, comet’s tails, or what have you—is probably right. But it isn’t—or a lot of it isn’t—nice plain water, ammonia, and methane.

  “THERE’S a lot of radiation in space, and a lot of innocent molecules floating around there get knocked apart. What you have left is radicals—highly-reactive fragments of molecules: NH, OH, C2, CH2, and so on. I suppose equilibrium temperature there in Newton’s permanent shadow can’t be more than twenty or or -thirty degrees absolute, so the radicals were “frozen”—held below even their very low activation temperature. I’m a little surprised you were able to run the tractors over the stuff safely—but I suppose the treads were pretty cold by the time you got there.

  “As for what finally touched off that tank, my guess would be the exhaust from Milt’s safety valves. You say he was running the machine full blast for several minutes, and. even in that environment it wouldn’t take what water he had left very long to heat up—after all, it must have been more than half gone by then anyway.”

  “It was,” confirmed Detzel. “We transferred it to our own tank, and didn’t manage to fill up even then. Without it, we’d have walked the last fifty miles back here.”

  “Well, that’s my hypothesis, then. I’m glad we don’t have to salvage some of that snow for the ship, though I suppose we could get away with it—add it a tiny bit at a time and let it react. The products would be useable enough. They’d be largely the water, ammonia, and methane Milt thought they were. That cleans up practically everything, I guess.”

  “Practically?” Imbriano was curious.

  Kinchen looked at him narrowly. “Just how sure are you that the plants Ingersoll discovered are Terrestrial, and that he was faking the find?”

  Imbriano hesitated before answering.

  “I know what I think, but I’ve done enough damage broadcasting it already,” he said at last. “I wish some of those specimens had been saved, and I certainly wish I’d had a chance to see what exposure to moon conditions did to those I put out. If they’d survived, or even formed viable spores . . .”

  “They’d have been quite radical, wouldn’t they?” asked Frake.

  He wondered why he was sent to look for more lichens.

  SUNSPOT

  That really close-up observations of the Sun would be useful is certain—but getting really close to the Sun is something else. A man would not have the chance of a snowball in Hell . . . or perhaps that’s just the chance he needs . . .

  RON Sacco’s hand reached gently toward his switch, and paused. He glanced over at the commander, saw the latter’s eyes on him, and took a quick look at the clock. Welland turned his own face away—to hide a smile?—and Sacco almost angrily thumbed the switch.

  Only one of the watchers could follow the consequences in real detail. To most, the closing of the circuit was marked a split second later by a meaningless pattern on an oscilloscope screen; to “Grumpy” Ries, who had built and installed the instrument, a great deal more occurred between the two events. His mind’s eye could see the snapping of relays, the pulsing of electrical energy into the transducers in the ice outside and the hurrying sound waves radiating out through the frozen material; he could visualize their trip, and the equally hasty return as they echoed back from the vacuum that bounded the flying iceberg. He could follow them step by step back through the electronic gear, and interpret the oscilloscope picture almost as well as Sacco. He saw it, and turned away. The others kept their eyes on the physicist.

  Sacco said nothing for a moment. He had moved several manual pointers to the limits of the weird shadow on the screen, and was using his slide rule on the resulting numbers. Several seconds passed before he nodded and put the instrument back in its case.

  “Well?” sounded several voices at once.

  “We’re not boiling off uniformly. The maximum loss is at the south pole, as you’d expect; it’s about sixty centimeters since the last reading. It decreases almost uniformly to zero at about fifteen degrees north; any loss north of that has been too small for this gear to measure. You’ll have to go out and use one of Grumpy’s stakes if you want a reading there.”

  No one answered this directly; the dozen scientists drifting in the air of the instrument room had already started arguments with each other. Most of them bristled with the phrase “I told you—” The commander was listening intently now; it was this sort of thing which had led him, days before, to schedule the radius measurements only once in twelve hours. He had been tempted to stop them altogether, but realized that it would be both impolite and impractical. Men riding a snowball into a blast furnace may not be any better off for knowing how fast the snowball is melting, but being men they have to know.

  Sacco turned from h
is panel and called across the room.

  “What are the odds now?”

  “Just what they were before,” snapped Ries. “How could they have changed? We’ve buried ourselves, changed the orbit of this overgrown ice cake until the astronomers were happy, and then spent our time shoveling snow until the exhaust tunnels were full so that we couldn’t change course again if we wanted to. Our chances have been nailed down ever since the last second the motors operated, and you know it as well as I do.”

  “I stand . . . pardon me, float . . . corrected. May I ask what our knowledge of the odds is now?” Ries grimaced, and jerked his head toward the commander.

  “Probably classified information. You’d better ask the chief executive of Earth’s first manned comet how long he expects his command to last.”

  Welland managed to maintain his unperturbed expression, though this was as close to outright insolence as Ries had come yet. The instrument man was a malcontent by nature, at least as far as speech went; Welland, who was something of a psychologist, was fairly sure that the matter went no deeper. He was rather glad of Ries’ presence, which served to bring into the open a lot of worrying which might otherwise have simmered under cover, but that didn’t mean that he liked the fellow; few people did. “Grumpy” Ries had earned his nickname well. Welland, on the present occasion, didn’t wait for Sacco to repeat the question; he answered it as though Ries had asked him directly—and politely.

  “We’ll make it,” he said calmly. “We knew that long ago, and none of the measures have changed the fact. This comet is over two miles in diameter, and even after our using a good deal of it for reaction mass it still contains over thirty billion tons of ice. I may be no physicist, but I can integrate, and I know how much radiant heat this iceberg is going to intercept in the next week. It’s not enough, by a good big factor, to boil off any thirty billion tons of the stuff around us. You all know that—you’ve been wasting time making a book on how much we’d still have around us after perihelion, and not one of you has figured that we lose more than three or four hundred meters from the outside. If that’s not a safe margin, I don’t know what is.”

  “You don’t know, and neither do I,” retorted Ries. “We’re supposed to pass something like a hundred thousand miles from the photosphere. You know as well as I do that the only comet ever to do that came away from the sun as two comets. Nobody ever claimed that it boiled away.”

  “You knew that when you signed up. No one blackmailed you. No one would—at least, no one who’s here now.” The commander regretted that remark the instant he had made it, but saw no way to retract it. He was afraid for a moment that Ries might make a retort which he couldn’t possibly ignore, and was relieved when the instrument man reached for a handhold and propelled himself out of the room. A moment later he forgot the whole incident as a physicist at one of the panels suddenly called out.

  “On your toes, all of you! X-ray count is going up—maybe a flare. Anyone who cares, get his gear grinding!” For a moment there was a scene of confusion. Some of the men were drifting free, out of reach of handholds; it took these some seconds to get swimming. Others, more skilled in weightless maneuvering, had kicked off from the nearest wall in the direction of whatever piece of recording machinery they most cherished, but not all of these had made due allowance for the traffic. By the time everyone was strapped in his proper place, Ries was back in the room, his face as expressionless as though nothing had been said a few moments before. His eyes kept swiveling from one station to another; if anyone had been looking at him, they would have supposed he was just waiting for something to break down. He was.

  To his surprise, nothing did. The flare ran its course, with instruments humming and clicking serenely and no word of complaint from their attendants. Ries seemed almost disappointed; at least Pawlak, the power plant engineer who was about the only man on board who really liked the instrument specialist, suspected that he was.

  “C’mon, Grump,” was this individual’s remark when everything seemed to have settled down once more. “Let’s go outside and bring in the magazine from the monitor camera. Maybe something will have gone wrong with it; you said you didn’t trust that remote-control system.”

  Ries almost brightened.

  “All right. These astronomers will probably be howling for pictures in five minutes anyway, so they can tell each other they predicted everything correctly. Suit up.” They left the room together with no one but the commander noting their departure.

  There was little space outside the ship’s air lock. The rocket had been brought as close to the center of the comet as measurement would permit, through a tunnel just barely big enough for the purpose. Five more smaller tunnels had been drilled, along three mutually perpendicular axes, to let out the exhaust of the fusion-powered reaction motors which were to use the comet’s own mass to change its course. One other passageway, deliberately and carefully zigzagged, had been cut for personnel. Once the sunward course had been established all the tunnels except the last had been filled with “snow”—crushed comet material from near the ship. The cavern left by the removal of this and the exhaust mass was the only open space near the vessel, and even that was not too near. No one had dared weaken the structure of the big iceberg too close to the rocket; after all, one comet had been seen to divide as it passed the sun.

  The monitor camera was some distance from the mouth of the tunnel—necessarily; the passage had been located very carefully. It opened in the “northern” hemisphere, as determined by direction of rotation, so that the camera could be placed at its mouth during perihelion passage and get continuous coverage. This meant, however, that in the comet’s present orbital position the sun did not rise at all at the tunnel mouth.

  Since pictures had to be taken anyway, the camera was at the moment in the southern hemisphere, about a mile from the tunnel mouth.

  Some care was needed in reaching it. A space-suited man with a mass of two hundred fifty pounds weighed something like a quarter of an ounce at the comet’s surface, and could step away at several times the local escape velocity if he wished—or, for that matter, if he merely forgot himself. A dropped tool, given only the slightest accidental shove sideways, could easily go into orbit about the comet—or leave it permanently. That problem had been solved, though, after a fashion. Ries and Pawlak attached their suits together with a snap-ended coiled length of cable; then they picked up the end of something resembling a length of fine-linked chain which extended off to the southwest and disappeared quickly over the near horizon—or was it around the comer? Was the comet’s surface below them, or beside or above? There was not enough weight to give a man the comforting sensation of a definite “up” and “down.” The chain had a loop at the end, and both men put one arm through this. Then Ries waved his free arm three times as a signal, and they jumped straight up together on the third wave.

  It was not such a ridiculous maneuver if one remembered the chain. This remained tight as the men rose, and pulled them gradually into an arc toward the southwest.

  Partway up, they emerged from the comet’s shadow, the metal suits glowing like miniature suns themselves. The great, gaseous envelope of a comet looks impressive from outside, seen against a background of black space; but it means exactly nothing as protection from sunlight even at Earth’s distance from the sun. At twenty million miles it is much less, if such a thing is possible. The suits were excellent reflectors, but as a necessary consequence they were very poor radiators. Their temperature climbed more slowly than that of the proverbial black body, but it would climb much higher if given time. There would be perhaps thirty minutes before the suits would be too hot for life; and that, of course, was the reason for the leap.

  A one-mile walk on the surface of the comet would take far more than half an hour if one intended to stay below circular velocity; swinging to their goal as the bobs on an inverted pendulum, speed limited only by the strength of their legs, should take between ten and twelve minutes. There
were rockets on their suits which could have cut even that time down by quite a factor, but neither man thought of using them. They were for emergency; if the line holding them to the comet were to part, for example, the motors would come in handy. Not until.

  They reached the peak of their arc, the chain pointing straight “down” toward the comet. Their goal had been visible for several minutes, and they had been trying to judge how close to it they would land. A direct hit was nearly impossible; even if they had been good enough to jump exactly straight up, the problem was complicated by the comet’s rotation. As it turned out, the error was about two hundred yards, fairly small as such things went.

  The landing maneuver was complicated-looking but logical. Half a minute before touchdown, Ries braced his feet against Pawlak and pushed. The engineer kept his grip on the chain and stayed in “orbit” while his companion left him in an apparently straight line. About fifteen seconds sufficed to separate them by the full length of the connecting snap line; the elasticity of this promptly started them back together, though at a much lower speed than they had moved apart. Just before they touched the surface, Ries noted which side of the camera the snap line was about to land on, and deliberately whipped it so that it fell on the other side; then, when both men took up slack, it snubbed against the camera mounting. Even though both men bounced on landing—it was nearly impossible to take up exactly the right amount of energy by muscle control alone—they were secure. Ries sent a couple of more loops rippling down the fine and around the camera mount—a trick which had taken some practice to perfect, where there was no gravity to help—and the two men pulled themselves over to their goal. The tendency to whip around it like a mishandled yo-yo as they drew closer was a nuisance but not a catastrophe; both were perfectly familiar with the conservation of angular momentum.