Commander Norton was sorely tempted but, as captain, his first duty was to his ship. If anything went badly wrong on this initial probe, he might have to run for it.
So that left his second officer, Lieut-Commander Mercer, as the obvious choice. Norton willingly admitted that Karl was better suited for the mission.
The authority on life-support systems, Mercer had written some of the standard textbooks on the subject. He had personally checked out innumerable types of equipment, often under hazardous conditions, and his biofeedback control was famous. At a moment’s notice he could cut his pulse-rate by fifty per cent, and reduce respiration to almost zero for up to ten minutes. These useful little tricks had saved his life on more than one occasion.
Yet despite his great ability and intelligence, he was almost wholly lacking in imagination. To him the most dangerous experiments or missions were simply jobs that had to be done. He never took unnecessary risks, and had no use at all for what was commonly regarded as courage.
The two mottoes on his desk summed up his philosophy of life. One asked WHAT HAVE YOU FORGOTTEN? The other said HELP STAMP OUT BRAVERY. The fact that he was widely regarded as the bravest man in the Fleet was the only thing that ever made him angry.
Given Mercer, that automatically selected the next man—his inseparable companion Lt. Joe Calvert. It was hard to see what the two had in common; the lightly-built, rather highly strung navigating officer was ten years younger than his stolid and imperturbable friend, who certainly did not share his passionate interest in the art of the primitive cinema.
But no one can predict where lightning will strike, and years ago Mercer and Calvert had established an apparently stable liaison. That was common enough; much more unusual was the fact that they also shared a wife back on Earth, who had borne each of them a child. Commander Norton hoped that he could meet her one day; she must be a very remarkable woman. The triangle had lasted for at least five years, and still seemed to be an equilateral one.
Two men were not enough for an exploring team; long ago it had been found that three was the optimum—for if one man was lost, two might still escape where a single survivor would be doomed. After a good deal of thought, Norton had chosen Technical Sergeant Willard Myron. A mechanical genius who could make anything work—or design something better if it wouldn’t—Myron was the ideal man to identify alien pieces of equipment. On a long sabbatical from his regular job as Associate Professor at Astrotech, the Sergeant had refused to accept a commission on the grounds that he did not wish to block the promotion of more deserving career officers. No one took this explanation very seriously and it was generally agreed that Will rated zero for ambition. He might make it to Space Sergeant, but would never be a full professor. Myron, like countless NCOs before him, had discovered the ideal compromise between power and responsibility.
As they drifted through the last airlock and floated out along the weightless axis of Rama, Lt. Calvert found himself, as he so often did, in the middle of a movie flashback. He sometimes wondered if he should attempt to cure himself of this habit, but he could not see that it had any disadvantages. It could make even the dullest situations interesting and—who could tell?—one day it might save his life. He would remember what Fairbanks or Connery or Hiroshi had done in similar circumstances…
This time, he was about to go over the top, in one of the early-twentieth-century wars; Mercer was the sergeant leading a three-man patrol on a night raid into no-man’s land. It was not too difficult to imagine that they were at the bottom of an immense shell-crater, though one that had somehow become neatly tailored into a series of ascending terraces. The crater was flooded with light from three widely-spaced plasma-arcs, which gave an almost shadowless illumination over the whole interior. But beyond that—over the rim of the most distant terrace—was darkness and mystery.
In his mind’s eye, Calvert knew perfectly well what lay there. First there was the flat circular plain over a kilometre across. Trisecting it into three equal parts, and looking very much like broad railroad tracks, were three wide ladders, their rungs recessed into the surface so that they would provide no obstruction to anything sliding over it. Since the arrangement was completely symmetrical, there was no reason to choose one ladder rather than another; that nearest to Airlock Alpha had been selected purely as a matter of convenience.
Though the rungs of the ladders were uncomfortably far apart, that presented no problem. Even at the rim of the Hub, half a kilometre from the axis, gravity was still barely one thirtieth of Earth’s. Although they were carrying almost a hundred kilos of equipment and life-support gear, they would still be able to move easily hand overhand.
Commander Norton and the back-up team accompanied them along the guide ropes that had been stretched from Airlock Alpha to the rim of the crater; then, beyond the range of the floodlights, the darkness of Rama lay before them. All that could be seen in the dancing beams of the helmet lights was the first few hundred metres of the ladder, dwindling away across a flat and otherwise featureless plain.
And now, Karl Mercer told himself, I have to make my first decision. Am I going up that ladder, or down it?
The question was not a trivial one. They were still essentially in zero gravity, and the brain could select any reference system it pleased. By a simple effort of will, Mercer could convince himself that he was looking out across a horizontal plain, or up the face of a vertical wall, or over the edge of a sheer cliff. Not a few astronauts had experienced grave psychological problems by choosing the wrong coordinates when they started on a complicated job.
Mercer was determined to go headfirst, for any other mode of locomotion would be awkward; moreover, this way he could more easily see what was in front of him. For the first few hundred metres, therefore, he would imagine he was climbing upward, only when the increasing pull of gravity made it impossible to maintain the illusion would he switch his mental directions one hundred and eighty degrees.
He grasped the first rung and gently propelled himself along the ladder. Movement was as effortless as swimming along the seabed—more so, in fact, for there was no backward drag of water. It was so easy that there was a temptation to go too fast, but Mercer was much too experienced to hurry in a situation as novel as this.
In his earphones, he could hear the regular breathing of his two companions. He needed no other proof that they were in good shape, and wasted no time in conversation. Though he was tempted to look back, he decided not to risk it until they had reached the platform at the end of the ladder.
The rungs were spaced a uniform half metre apart, and for the first portion of the climb Mercer missed the alternate ones. But he counted them carefully, and at around two hundred noticed the first distinct sensations of weight. The spin of Rama was starting to make itself felt.
At rung four hundred, he estimated that his apparent weight was about five kilos. This was no problem, but it was now getting hard to pretend that he was climbing, when he was being firmly dragged upwards.
The five hundredth rung seemed a good place to pause. He could feel the muscles in his arms responding to the unaccustomed exercise, even though Rama was now doing all the work and he had merely to guide himself.
“Everything OK, Skipper,” he reported. “We’re just passing the halfway mark. Joe, Will—any problems?”
“I’m fine—what are you stopping for?” Joe Calvert answered.
“Same here,” added Sergeant Myron. “But watch out for the Coriolis force. It’s starting to build up.”
So Mercer had already noticed. When he let go of the rungs he had a distinct tendency to drift off to the right. He knew perfectly well that this was merely the effect of Rama’s spin, but it seemed as if some mysterious force was gently pushing him away from the ladder.
Perhaps it was time to start going feet-first, now that “down” was beginning to have a physical meaning. He would run the risk of a momentary disorientation.
“Watch out—I’m going to swing round.”
Holding firmly on to the rung, he used his arms to twist himself round a hundred and eighty degrees, and found himself momentarily blinded by the lights of his companions. Far above them—and now it really was above—he could see a fainter glow along the rim of the sheer cliff. Silhouetted against it were the figures of Commander Norton and the back-up team, watching him intently. They seemed very small and far away, and he gave them a reassuring wave.
He released his grip, and let Rama’s still feeble pseudogravity take over. The drop from one rung to the next required more than two seconds; on Earth, in the same time, a man would have fallen thirty metres.
The rate of fall was so painfully slow that he hurried things up a trifle by pushing with his hands, gliding over spans of a dozen rungs at a time, and checking himself with his feet whenever he felt he was travelling too fast.
At rung seven hundred, he came to another halt and swung the beam of his helmet-lamp downwards; as he had calculated, the beginning of the stairway was only fifty metres below.
A few minutes later, they were on the first step. It was a strange experience, after months in space, to stand upright on a solid surface, and to feel it pressing against one’s feet. Their weight was still less than ten kilograms, but that was enough to give a feeling of stability. When he closed his eyes, Mercer could believe that he once more had a real world beneath him.
The ledge or platform from which the stairway descended was about ten metres wide, and curved upwards on each side until it disappeared into the darkness. Mercer knew that it formed a complete circle and that if he walked along it for five kilometres he would come right back to his starting point, having circumnavigated Rama.
At the fractional gravity that existed here, however, real walking was impossible; one could only bound along in giant strides. And therein lay danger.
The stairway that swooped down into the darkness, far below the range of their lights, would be deceptively easy to descend. But it would be essential to hold on to the tall handrail that flanked it on either side; too bold a step might send an incautious traveller arching far out into space. He would hit the surface again perhaps a hundred metres lower down; the impact would be harmless, but its consequences might not be—for the spin of Rama would have moved the stairway off to the left. And so a falling body would hit against the smooth curve that swept in an unbroken arc to the plain almost seven kilometres below.
That, Mercer told himself, would be a hell of a toboggan ride; the terminal speed, even in this gravity, could be several hundred kilometres an hour. Perhaps it would be possible to apply enough friction to check such a headlong descent; if so, this might even be the most convenient way to reach the inner surface of Rama. But some very cautious experimenting would be necessary first.
“Skipper,” reported Mercer, “there were no problems getting down the ladder. If you agree, I’d like to continue towards the next platform. I want to time our rate of descent on the stairway.”
Norton replied without hesitation.
“Go ahead.” He did not need to add, “Proceed with caution.”
It did not take Mercer long to make a fundamental discovery. It was impossible, at least at this one-twentieth-of-a-gravity level, to walk down the stairway in the normal manner. Any attempt to do so resulted in a slow-motion dreamlike movement that was intolerably tedious; the only practical way was to ignore the steps, and to use the handrail to pull oneself downwards.
Calvert had come to the same conclusion.
“This stairway was built to walk up, not down!” he exclaimed. “You can use the steps when you’re moving against gravity, but they’re just a nuisance in this direction. It may not be dignified, but I think the best way down is to slide along the handrail.”
“That’s ridiculous,” protested Sergeant Myron. “I can’t believe the Ramans did it this way.”
“I doubt if they ever used this stairway—it’s obviously only for emergencies. They must have had some mechanical transport system to get up here. A funicular perhaps. That would explain those long slots running down from the Hub.”
“I always assumed they were drains but I suppose they could be both. I wonder if it ever rained here?”
“Probably,” said Mercer. “But I think Joe is right, and to hell with dignity. Here we go.” The handrail—presumably it was designed for something like hands—was a smooth, flat metal bar supported on widely-spaced pillars a metre high. Commander Mercer straddled it, carefully gauged the braking power he could exert with his hands, and let himself slide. Very sedately, slowly picking up speed, he descended into the darkness, moving in the pool of light from his helmet-lamp. He had gone about fifty metres when he called the others to join him. None would admit it, but they all felt like boys again sliding down the banisters. In less than two minutes, they had made a kilometre descent in safety and comfort. Whenever they felt they were going too fast a tightened grip on the handrail provided all the braking that was necessary.
“I hope you enjoyed yourselves,” Commander Norton called when they stepped off at the second platform. “Climbing back won’t be quite so easy.”
“That’s what I want to check,” replied Mercer, who was walking experimentally back and forth, getting the feel of the increased gravity. “It’s already a tenth of a gee here—you really notice the difference.”
He walked—or, more accurately, glided—to the edge of the platform, and shone his helmet-light down the next section of the stairway. As far as his beam could reach, it appeared identical with the one above—though careful examination of photos had shown that the height of the steps steadily decreased with the rising gravity. The stair had apparently been designed so that the effort required to climb it was more or less constant at every point in its long curving sweep.
Mercer glanced up towards the Hub of Rama, now almost two kilometres above him. The little glow of light, and the tiny figures silhouetted against it, seemed horribly far away. For the first time, he was suddenly glad that he could not see the whole length of this enormous stairway. Despite his steady nerves and lack of imagination, he was not sure how he would react if he could see himself like an insect crawling up the face of a vertical saucer more than sixteen kilometres high—and with the upper half overhanging above him. Until this moment, he had regarded the darkness as a nuisance; now he almost welcomed it.
“There’s no change of temperature,” he reported to Commander Norton. “Still just below freezing. But the air pressure is up, as we expected—around three hundred millibars. Even with this low oxygen content, it’s almost breathable; further down there will be no problems at all. That will simplify exploration enormously. What a find—the first world on which we can walk without breathing gear! In fact, I’m going to take a sniff.”
Up on the Hub, Commander Norton stirred a little uneasily. But Mercer, of all men, knew exactly what he was doing. He would already have made enough tests to satisfy himself.
Mercer equalized pressure, unlatched the securing clip of his helmet, and opened it a crack. He took a cautious breath; then a deeper one.
The air of Rama was dead and musty, as if from a tomb so ancient that the last trace of physical corruption had disappeared ages ago. Even Mercer’s ultra-sensitive nose, trained through years of testing life-support systems to and beyond the point of disaster, could detect no recognizable odours. There was a faint metallic tang, and he suddenly recalled that the first men on the Moon had reported a hint of burnt gunpowder when they repressurized the lunar module. Mercer imagined that the moon-dust-contaminated cabin on Eagle must have smelled rather like Rama.
He sealed the helmet again, and emptied his lungs of the alien air. He had extracted no sustenance from it; even a mountaineer acclimatized to the summit of Everest would die quickly here. But a few kilometres further down, it would be a different matter.
What else was there to do here? He could think of nothing, except the enjoyment of the gentle, unaccustomed gravity. But there was no point in growing used to that, since they would be returning immediately to the weightlessness of the Hub.
“We’re coming back, Skipper,” he reported. “There’s no reason to go further until we’re ready to go all the way.”
“I agree. We’ll be timing you, but take it easy.”
As he bounded up the steps, three or four at a stride, Mercer agreed that Calvert had been perfectly correct; these stairs were built to be walked up, not down. As long as one did not look back, and ignored the vertiginous steepness of the ascending curve, the climb was a delightful experience. After about two hundred steps, however, he began to feel some twinges in his calf muscles, and decided to slow down. The others had done the same; when he ventured a quick glance over his shoulder, they were considerably further down the slope.
The climb was wholly uneventful—merely an apparently endless succession of steps. When they stood once more on the highest platform, immediately beneath the ladder, they were barely winded, and it had taken them only ten minutes. They paused for another ten, then started on the last vertical kilometre.
Jump—catch hold of a rung—jump—catch—jump—catch… it was easy, but so boringly repetitious that there was danger of becoming careless. Halfway up the ladder they rested for five minutes: by this time their arms as well as their legs had begun to ache. Once again, Mercer was glad that they could see so little of the vertical face to which they were clinging; it was not too difficult to pretend that the ladder only extended just a few metres beyond their circle of light, and would soon come to an end.
Jump—catch a rung—jump—then, quite suddenly, the ladder really ended. They were back at the weightless world of the axis, among their anxious friends. The whole trip had taken under an hour, and they felt a sense of modest achievement.
But it was much too soon to feel pleased with themselves. For all their efforts, they had traversed less than an eighth of that cyclopean stairway.