Carter climbed aboard as Nelson circled the vehicle, his eyes passing from the neon checklist to the vehicle and back. He moved in closer and got down on his knees to check the under-carriage. Everything appeared to be in order.
“
Liberty
,” he said as he sat down next to Carter, “Olympus Mission Alpha is under way.”
“Best of luck,” Endicott replied.
Nelson slapped his hand on Carter’s knee. “You know what to do,” he said.
Carter had the vehicle up to its cruising velocity of thirty-two kilometers per hour within seconds of starting. The rocks were everywhere. They spread out before him like tombstones, and, much to his annoyance, he often had to slow down just to avoid them. The tortuous path he was forced to take would more than triple the distance to the cliff. He relied on Nelson to keep him on course. At the center of the control panel was a computer screen that presented a variety of navigational data. Nelson had his choice of radar images, two- and three-dimensional topographical maps, geological maps, and photographic overheads. The position of the rover was marked by an X, with a black solid line winding back to the
Shepard
and a green dotted line stopping at the base of the volcano. Their longitude and latitude, within thirty-eight centimeters of their actual position, was displayed at the bottom of the screen along with a recommended heading. A geostationary satellite, which had arrived two years earlier, updated their coordinates. In the event the communications link was lost, the onboard computer kept track of their location by dead reckoning. The computer was also capable of directing the rover without the aid of a human driver. The digital cameras just above the halogen headlights were used to locate and determine the size of obstacles. A safe course would then be calculated. Carter took solace in the knowledge that the rover’s speed was drastically reduced without a human at the helm.
At a distance of twenty-seven kilometers the base of Olympus Mons dominated the horizon. It stood five and one-half kilometers high and blocked from view the peak of the volcano that lay behind it, and with each kilometer that bounced underneath them it grew even larger. Bit by bit the sky was disappearing. They knew, when they reached the volcano, they would have to look straight up to see the sky.
“Bear due north for the next one-point-seven klicks,” Nelson said. “The detour will take us about five and a half klicks out of our way. The ground is broken up pretty bad. Several lava tubes have collapsed in this region.” He was pointing at a spot on the screen. Carter did not take the time to look. He had spotted a large rock in the horizon that was due north and was doing his best to head toward it. For the moment it was somewhere off his left shoulder.
While training in Hawaii, Nelson had stood inside a lava tube that was nearly ten meters wide; it was, the instructor had told him, one of the largest on Earth. He was impressed until the instructor had also told him that it was a dwarf compared to the tubes of Olympus Mons, which were over two hundred meters wide. He was tempted to direct Carter toward the tubes, but their schedule was tight. They were to be at the first collection point in less than twenty minutes.
Upon examining the topographical on the screen, Nelson searched his surroundings in an attempt to confirm his position. With the exception of the volcano, there were very few distinguishing landmarks. He was looking for boulders positioned in recognizable patterns. But the patterns he viewed on the screen were from a top-down perspective, and he was among the rocks, not above them, so the patterns took on a different aspect. He wasn’t that concerned. There was really little need to identify the boulders—it was highly unlikely that the coordinates displayed by the navigational subsystem were incorrect.
The twenty minutes passed quickly. Nelson motioned to a spot thirty meters up ahead, an opening among several larger rocks, two of which were almost half the size of the rover. He signaled for Carter to stop when they arrived.
“
Liberty
, Collection Point Alpha has been achieved. It is twenty-three hundred hours GMT and . . .” he added, looking up at the sun, “. . . just about high noon here. Over.”
“One hour is scheduled for this collection point,” Endicott replied.
The surface drill resembled a thin jackhammer. It was powered by the silver-zinc batteries on the rover, and was capable of digging through dirt and sand, but not through dense rock. Nelson was growing frustrated as he bore down on the drill. It was not going anywhere. He carefully removed it from the soil. He was surrounded by holes of failed attempts. His space suit was beginning to bother him.
He looked at his watch to check the time. Fifteen minutes left, and he had only extracted two of the desired eight core samples. He walked over to a rock and sat down. He held the drill up at eye level to inspect it closely, as if the drill were at fault and not the ground. He rotated it slowly. The shiny metallic surface glowed pink from the reflection of the horizon and the sand. He didn’t really expect to find anything wrong with it; it just gave him something to do while he rested. Carter came sauntering over.
“Something wrong with the drill?” Carter drawled.
“It’s not the drill,” Nelson said. “It’s the ground.”
“Maybe you’ll have better luck down the road.” Carter chose a rock next to his commander. “You hungry?”
“Depends on what you packed,” Nelson replied. “NAS-SPEC 5601.”
“Which is?”
“Don’t rightly recall. Rather keep it a mystery personally.” Carter pressed a small button on the chest panel of his soft-suit. He watched with crisscrossed eyes as a clear tube slowly made its way to his mouth from somewhere inside his space suit. At the far end of the tube was an aluminum canister containing a plastic bag packed with NAS-SPEC 5601. As he sucked, a mushy substance crept up the tube and into his mouth. It was slightly cold and lumpy and tasted something like tuna fish.
“It’s all in the mind,” he said, pointing at his head.
T
hey drove for an hour before they reached the next collection point. The ground was softer, and Nelson was able to extract all ten samples without too much difficulty. They rested and had their snacks and stared at the red wall of stone that dominated the sky. They could barely make out the twin towers through the high-powered binoculars. The towers appeared to be of a darker shade than the cliff behind them. They could not see the top of the cliff without leaning back on the rock they were sitting upon.
“We’re not even going to scratch the surface,” Carter said after a while.
Nelson looked at the volcano and wondered if anyone would ever climb to the top. It did not seem possible. But he knew that someone would eventually try. He would have liked to give it a try himself. They were to ascend a ridge along the side of the cliff for nearly six hundred meters before it broke off. The steepest grade would be approximately thirty degrees. The cliff itself was a sheer drop.
“How much farther?” Carter asked.
“Five klicks without detours, fifteen with. It shouldn’t take much longer than an hour.”
The cliff was composed of horizontal bands, which grew more distinct and intricate as they approached. Nelson was fascinated by the different shades that emerged. There was no longer any need to give directions—their destination was in sight. At five hundred meters the twin towers started to stand out. They stopped the rover once to look and take pictures. It was an unscheduled stop, but they were ahead of schedule, and Carter insisted. Seven minutes passed, and they were on their way again. The twin towers appeared man-made, or at least built by some form of intelligent life. Their shapes appeared too symmetrical to be created by the whims of nature. But neither Carter nor Nelson thought the towers were created by anything other than nature. The other possibilities were far too speculative to warrant much consideration. Through the binoculars, Nelson was able to make out irregularities in the formations. The two rocks stood alone. Nelson scanned the surface with the binoculars and was unable to locate any other formation vaguely similar to the towers. At one hundred meters, Nelson put the binoculars down. The two towers were approximately ten meters apart and stood twenty meters high. They were almost identical in height and approximately two and one-half meters in diameter, slightly wider at the bottom. They looked very much like columns from ancient Rome. The sight sent a shiver down Nelson’s spine. There was something very eerie about two rock formations that looked like Roman columns at the base of a volcano on a planet other than Earth. But as they got closer the columns looked more like something carved by water. They tapered in the direction of what might have been the flow of a river. Carter stopped the rover a respectful twenty meters from the formation.
“How do you suppose it came about?” he asked.
“Some sort of natural formation,” Nelson replied. “The rock is much darker, almost black. Takashi, would you care to speculate?”
“They appear to be basaltic,” Satomura said. He was studying the images from the
Gagarin
. With Brunnet gone, Satomura was the only geologist among the two crews. “There is some speculation that Olympus Mons was once even larger than it is today. I suspect you are looking at the remnants of a collapsed volcano. The cliff before you tends to support this. The rock was probably carved into columns by lava.”
“Which explains why they taper away from the volcano,” Nelson said.
“Yes, the shape is much like we would have expected. It also explains why there are so few rocks about. They’ve been washed away by lava. A core sample of the column should settle the issue.”
“All in good time, Doctor,” Carter interrupted. “Right now we need to set up camp.”
“Yes, of course,” Satomura replied.
N
elson was staring at the triangular patterns stitched in the fabric of the tent. Two hours had passed since he had crawled inside his sleeping bag, and he had not yet fallen asleep. His excitement for the climb had kept him awake. The temperature outside the tent was seventy degrees centigrade below zero. The fabric of the tent crackled like paper. He was fine inside his sleeping bag. Carter was snoring. He had fallen asleep within seconds of lying down.
Nelson’s thoughts turned to the debate about whether they should climb the ridge. Those opposed said it was too dangerous, while those in favor fervently disagreed. No one had known about the ridge prior to their arrival. Scientists on Earth had discovered it while examining photographs of the landing. It presented a valuable opportunity to collect samples from different strata. There was a lot of speculation as to its origin. Most of it unscientific. Twin Roman towers at the base of a ridge that looked convincingly like an ancient roadway could only have been constructed by an intelligent race, or so the tabloids went. The scientists were able to demonstrate it had been caused by nothing more than a fault in the regolith. It was finally agreed that the first six hundred meters of the ridge were wide enough not to pose a risk. Nelson was thrilled with the decision. To climb Olympus Mons was something he had wanted to do from the very first day the landing site was selected, but had not even dared to suggest. But now, because of the ridge, he would be able to make the climb. He glanced at his watch. If he were to be well rested, he would have to go to sleep soon. He pulled the sleeping bag over his head and thought of the twin towers. The core samples they had taken supported Satomura’s belief that the towers were the remnants of a larger volcano. Recalling the sheer height of the cliff, which formed only the base of Olympus Mons, he found it difficult to imagine the volcano having been much larger.
T
he day was nearly half-spent, and the astronauts were growing tired from the climb. Although they had stopped several times to collect samples, they had not taken a break. Their muscles ached, and their life-support packs felt as if they were made of lead. Despite several hours a day on the stationary bike, they still were not in the physical condition required to tackle the thirty-degree slope before them. They were standing on a ridge, approximately six meters wide, that hugged the cliff like a small roadway. Carter approached the edge and looked down. They were two hundred meters from the surface, and the drop was nearly straight down. The top-heaviness of the softsuit made him feel uneasy about his footing. He cautiously stepped away from the edge.
“Another five minutes,” Nelson said, “and we should be there.”
Carter eyed the heads-up-display clock at the lower right-hand side of his helmet. The numbers flickered green. Another five minutes, he repeated to himself for the benefit of his aching muscles. He trudged forward, his eyes focused several meters in front of his feet. The ground was rocky and porous, and with each step the dust at his feet exploded into mushroom clouds.
“Hold up,” Nelson said, probing the ground with a sonar stick. “This must be some sort of overhang. We’d better move closer to the wall.”
Carter stopped and looked around. The edge was more than half a meter away, a distance he would have normally considered safe. As he took a step toward the wall, the ground underneath his feet began to crumble. Nelson was in front of him with his back turned. He attempted to throw himself forward onto the ridge, but there was nothing for his feet to push off against. His yell for help came much too late. He was falling backwards—the sky was bright pink. Nelson was shouting something into his helmet. He knew that he was going to die as soon as he hit the ground. But he did not want to die. He tried to think of what he should do. In parachute training they had taught him to roll to break the impact. He slammed against the side of the volcano and started to tumble.
He hit the ledge hard. There was a loud snap like a stick breaking. At first he couldn’t breathe. Short, white streaks twirled in front of his eyes. He realized he was about to pass out and struggled to maintain consciousness. His leg was screaming with pain. It felt as though an ice pick were tearing through the flesh. He looked down at the limb. It twisted out from beneath him at a weird angle. A compound fracture, he thought. He attempted to move his leg, but the pain was overwhelming. He lost consciousness.