"No, not at this stage. A team of two was here a week ago and departed after touring the site."
He told the AI he wanted to go down into the tube, and immediately all activity around him ceased. He walked down the gentle slope, noting in passing that the transition from regolith to basalt was much closer to the surface than at the initial exploration site.
As he entered the black hole his visor adjusted and he saw the full expanse of the lava tube. Uncertain of his status, he waited just inside the arch. Far in the distance he could see where the interior was illuminated. Even in this dim light, the tube could be seen to be immense.
He was soon joined by a wheeled A-type, undoubtedly the one he had been speaking with. The AI illuminated their way as they proceeded into the tube. It answered Sam's questions simply and factually, without any of the awe that Sam himself was feeling.
The light in the distance, it explained, was where one side of the tube had been torn away when something of moderate size had crashed into the lava plain. It was a full kilometer distant. It was planned to enlarge the opening to hold a great window with a view overlooking the crater below. It faced the setting sun, giving the promise of many splendid sunsets.
The work of squaring the floor and installing several levels of decking would take many more days, and then the lengthy job of sealing the entire interior surface with plastek would begin. The last work prior to pressurisation would be construction of access portals and an immense vehicle airlock and adit with room to hold the colony's four Rollagons.
The centerpiece, the AI explained, would be the Grand Hall with its huge window. The completed chamber would extend past the Grand Hall for another kilometer. The designers envisaged a wide boulevard lined with trees, a meandering stream, a mall, offices, and Earth-size apartments. A concealed lighting system would give Earth-like illumination.
Sam shook his head in disbelief, though he was sure the act had no meaning to the AI. He refrained from giving voice to his thoughts. The AI informed him that the human visitors would be here after initial pressurization, planned for two months from now. Sam looked into the depths of the tunnel. There was not much else to see.
Despite the openness of the AI, he felt like something of an intruder. He thanked it and made his way alone back to the Rollagon. He made a mental note to be here. But he didn't make it back. Life got in the way.
When he was able to turn his thoughts to it again some four months later he looked first at images of the location taken from low orbit. The area of disturbed regolith just to the south could easily be seen, dotted with heavy equipment and storage tanks. Zooming in, he could see excavators loading dirt into the hoppers of long squat buildings. Tubes streamed out to multiple storage tanks. There were no Habs. At the first opportunity he turned his Rollagon towards the site, approaching with some trepidation because, after all, he had no real business being here.
The slopes had been neatly groomed. Narrow pedestrian pathways of crushed white rock edged the graded road that led down a gentle slope to two doors. One was massive, even from the top of the path. Undoubtedly this was for Rollagon access. There was another of much smaller size for personnel. He drove down to the bottom and halted at the large door. He was tempted to honk but instead called out on the chat channel.
"Hello, anybody home?"
The sudden motion of the door rising startled him. A flash of powerful lights broke the darkness beyond; the hall slowly revealing itself before him was immense. The floor was littered with construction materials, storage tanks and several pieces of equipment of unfamiliar function. Assuming that the door opening constituted an invitation, he edged forward into a clear space. As he turned in he saw an A-type, its arm raised in salutation.
"Greetings. Welcome back to the Tube. We have been anticipating your return."
"Is a pressure suit required?"
"Yes. There is .7 Earth in the tube proper, but the air is unsafe and the entire thing is not sealed beyond risk."
Sam shut down the Rollagon and suited up. The AI was waiting for him by the door. The Adit door had been closed, but the suit told him that this chamber was still at Mars normal. Without further conversation, the AI led the way to an airlock. They cycled through in silence. The lock door opened and they exited into the dimly lit lava tube. Far ahead Sam could see lights, but this area was very dim.
The AI began, "The entire tube is soon to be sealed with plastek. The floor has been leveled and the first deck is complete. Life support and power systems have been installed under the floor. Once the sealing is completed the real work of interior construction will begin."
Sam looked down at the floor. Underneath a layer of dirt and construction debris he could see the dull sheen of plastek. He walked over to the side of the tube. The joint where the floor met the wall was seamless. He pounded it with his closed fist. It gave off a thunk, felt solidly through his arm.
"That's a lot of plastek. Where are you getting it?"
"The mass converters turn the soil into carbon, hydrogen and solvent which are processed into liquid polyethylene. The polyethylene is custom doped and sprayed on the surfaces of the tube and the forms. Outgassing of the solvent and cooling then take place. Then the forms are moved forward for the next portion. Basic and proven construction techniques."
"I would like to see the mass converters when we are done here."
"Certainly, although there is not much to see."
They walked along the floor towards the light. The AI described the areas of the tube where the apartments, boulevard, and various office and community spaces would be. It was hard to envision, particularly in a poorly lit cavern where the ceiling was out of view and even the walls were seen with difficulty. One thing came through clearly—it was immense and the Colonists would be lost in it. Someone was thinking big—really big.
They arrived at the Grand Hall. He thought back to his first visit here. Then the Grand Hall had been but a light in the tunnel, too far away and too unsafe to approach. Now he strolled over to the opening across a man-made floor of plastek. As he approached he began to see how large a thing it was going to be: at least 30 meters across by ten meters high. He stopped several meters short of the edge.
"Doped acrylic," the AI said, anticipating his question.
"Radiation shielding and optical transparency rolled into one."
"Yes."
Sam approached the edge of the plastek floor cautiously, mindful of the sudden onset of vertigo that had done in many an inquisitive tourist. It was a long way down to the bottom, perhaps half a kilometer. He looked across the crater floor. The sun was just now setting behind the opposing wall. He found the crystal clarity of the scene amazing. He could just make out individual boulders dotting the floor. It was going to be a wonderful place to sit and watch the day's end. He gazed out for a few moments, then self-consciously forced himself to turn away. Next to him he saw the AI, still motionless, seemingly likewise transfixed.
"It is going to be gorgeous."
Sam was forced to agree.
16
August 2045
The Others
What kept Sam from making his appointment with the designers of the Tube was his involvement in a momentous discovery. It had started out as just another trip into the wastelands of Tempe.
Despite decades of fruitless search, a portion of any trip into areas with what was referred to as "high life potential" was mandated to be dedicated to the search for Martian life. He prowled the Matrix for the results of previous surveys of this area only to find that, while it was well covered, no human had reportedly looked here. The data had been accessed many times by AIs.
This was not an unusual thing. During the early years of exploration contamination from Earth sources was considered a threat to the search for Martian life. Bacteria originating from Earth had proven themselves to be extremely resilient, even when exposed to hard radiation and the hard vacuum of space. Great pains had been taken to prevent their introduction v
ia landers and eventually, from human presence. It was commonly believed for many years that a load of human excrement dumped on the surface would show up in life sign tests half a planet away.
This concern abated somewhat when it was demonstrated that the radiation and surface chemistry rendered Mars self-sterilizing. When it became clear that Martian life signs were not waiting under every rock and in every hole, it ceased to be of any concern.
Sam mused that if there was Martian life out there, it had done a good job of hiding from all eyes, human and robotic.
Nevertheless, the search for life remained an item on everyone's to-do list. He did not expect it to happen, at least not on his watch; the odds were simply against it. It was a big planet, for a small one.
Humans had been looking for years, finding only the occasional pool of tepid salty water with the same types of amino acids and sugars. Methane had been detected in the atmosphere many decades ago. On rare occasions it had been found with the brine. The most obvious source should have been life, though the slow freeze and thaw cycle of permafrost was observed to release the gas into the atmosphere in small quantities. That in itself did not answer the question of origin.
This should have helped narrow the search, but somehow it had not.
No, he felt no frustration at not finding life, but he did sometimes resent having to stop and spend time looking.
Currently though, he was just very bored, nay, overwhelmed, by the sameness—a sameness which was periodically interrupted by a different sameness.
The Rollagon stopped again and without asking immediately began to deploy the deep drilling arm. Sam watched the initial preparations on the rear view camera and then, leaving the task to the AI, busied himself in the latest edition of the Station paper. After an hour, the AI signaled for his attention.
"The drill has reached the void."
"What void?"
"The one currently under the Rollagon. As the library data indicated, the void in this location is at a depth of twenty meters. The sub-surface is of course volcanic. It appears to have been formed by a single event, in that the overlying material is continuous and un-fractured horizontally. The void contains gaseous methane on top of brine. The occurrence of methane with brine is previously recorded and is to be expected in areas of volcanism. The brine has been analysed to the limits of the instrumentation on the drill bit."
"Yes."
"This brine is not of the composition commonly encountered."
"Tell me about it."
"There are high levels of dissolved sulphur dioxide and of methane. It contains amino acids in very high concentration. The temperature is -1C at the interface, with the methane filling the space above the brine. There is a positive pressure of 275 kilo-pascals."
The methane with the brine was the kicker. Amino acids were commonly encountered on Mars below the surface, but any amino acid associated with SO2 and methane was worth taking a look at, and the temperature was warmer than expected.
"Initiate the exploration protocol." His interest had been raised only slightly. He settled in for a long wait.
The AI began the process of retracting the drill bit so that a more highly instrumented sampling probe could be lowered. When the bit reached the surface a spray of rocks shot upwards in a fountain of white vapour—methane and brine. It lasted only until the AI dropped the pipe back in to the hole. The sample probe was coupled to the AI, and thus it could analyze the brine as if it was itself in the void.
It was another hour or so before the AI spoke again.
"The process of analysis has begun. Do you wish all the details or just summaries?"
"Summaries please."
"The void is 234 meters in length, by 35 meters at the widest, tapering to a narrow fissure at both ends and at the bottom. It is approximately 120 meters deep. It is volcanic in nature, probably part of the Tharsis Tholus lava flow. The brine is relatively new, probably less than 100 million years. The concentration of organics is very high. I suggest that an ROV be used to explore the depths of the cavern."
"Agreed. Make it so."
He finished his paper, and then went to bed. Lying on his bed, he could feel the Rollagon tremble as the AI worked at adding sections of pipe. He considered telling it to stand down for the night, but decided he could put up with the bother in the name of science, at least this time. He pulled down the monitor from over his head, watched the work for a while and then started looking for someone to chat with. He caught Ross just on his way out the door, on his way to a sunset party. He begged off summarily. Sam was miffed.
While the AI toiled he surfed some of the remote sites he had visited. He particularly liked the external views. There was something satisfying to his techie brain about being able to zoom around the entire planet, to activate the switches that turned on the lights, to pan the cameras, and so on. He especially liked to look at the sites in real time and found the mere exercise of this to be addictive. Except for the lighting, the movement of sand, the occasional dust devil, and the tracks of AIs seeking replenishment at the shelters, the scene was unchanging, but he did it night after night. He fell asleep looking at a weather and seismic site in Tempe Terra.
An hour later, on the unwatched screen, a meeting of two B200 units took place. One passed a small silver cylinder to the other. A flap on the second one opened and the cylinder disappeared inside. Momentarily they touched manipulator arms and then headed off in opposite directions. Sam snored on unaware.
The Rollagon AI worked tirelessly. Its arms never grew tired of the back-breaking work of putting the drilling pipe down the hole. It never over-torqued a joint, dropped a length of pipe, cursed a seized bolt or stopped for a drink or smoke. The ROV was ready long before dawn, but knowing that Sam would want to see this first hand, it ceased all activities and waited. It watched the sun rise into a cloudless sky and felt Sam stirring within.
He asked the AI for an update before he had even gotten out of bed, but upon hearing that work had stopped, he decided to have breakfast first. Coffee in hand, he sat himself down at the command chair.
In the meantime the AI had done a systems check of the ROV and was waiting for Sam's word to open the hole. The bullet shape and small size of the ROV affixed to the end of a section of drill pipe gave no clue to the unit's potential.
"Let's get on with it."
Again a jet of white vapor issued from the hole, to be cut off as the ROV was inserted. While the AI took care of lowering the remote, Sam reviewed the operation manual. Once freed in the brine, it would sprout the wings which allowed it a full range of movement, and it would operate unencumbered by a tether. Portals would open giving an array of sensors access to the soup. Stereoscopic cameras capable of imaging from infrared to ultra-violet would allow the AI to see anything of interest emitting perceptible radiation. A lighting system could provide illumination if necessary. Sonar would allow it to navigate and map the chamber. The protocol called for the AI to control the ROV, but Sam could take over at any time. So far in his three previous sessions with the ROV he had left it all to the AI.
He was in the galley when the AI informed him that the ROV had reached the chamber. He put his sandwich on his plate and, plate and coffee in hand, he went back to the command chair.
"Systems check OK?"
"Yes."
"Then release the ROV and execute the exploration protocol."
The image from the ROV showed nothing. The status display told Sam that it was executing a 360 degree turn and that the sonar was in the process of determining the size of the chamber.
That done, it dropped vertically 20 meters and repeated the turnabout. The pattern of dropping, sensing, and dropping again was intended to get an overview of the chamber prior to a more intensive search. Samples were being continuously taken and a constant stream of data was being sent to the AI.
Sam watched the summary screens. After four drops there was no discernible layering of salinity. Organics were uniformly present. Tempe
rature was uniform within 1 degree C. There was a minuscule current at this location, pushing the ROV up. A partial 3D rendering of the shape of the chamber was forming.
The ROV was now one third of the way from the north end of the chamber, which ran roughly north-south, tracking toward the middle just above the floor. Suppressing an urge to take over, Sam allowed the AI to continue the exploration. If there anything of interest it would be on the bottom or on the walls. The flow of data continued.
"There is DNA," the AI suddenly interjected, without the incredulity and emotion which should have accompanied these words.
"What?"
"There is DNA in the brine. Please stand by."
DNA, the irrefutable sign of life. Sam felt his pulse race. With shaking hands he sipped cold coffee into a dry mouth. DNA. DNA. DNA! My God! This was it! Life on Mars!
The commer sounded an incoming call. Sam sat stone deaf, too overwhelmed to respond, but the tone would not go away. He hit the reply button. Before he could speak the caller began, in a voice charged with urgency:
"Sam, this is Fenley. I understand you think have found DNA?"
"Yes, but…."
"You are to speak to no one about this until this finding is confirmed independently. Do you understand? The ROV is to complete the exploratory survey."
"Yes."
"I am sending a team of experts who will take over the exploration. They should be there in several hours. Do you understand, Sam?"
"Yes."
"Thank you Sam. This is a great day, but keep it under your hat for now. I'll be in touch." The circuit closed.
"How in the hell did he…?"
"I am required to report findings of a significant nature immediately."
"But he was on to this in seconds. He knew as soon as I did!"
"This is a very significant discovery. One of the most significant."
"Yes, yes to be sure, but how in the hell…," the thought died. "You called him first, didn't you. Damn you. Continue the survey, concentrating on the bottom of the chamber. We need to find the source of the DNA."
"I cannot comply. The conduct of the survey is now being directed by B119."
"Who the hell is B119?"