Before breakfast, Tae had taken a pair of scissors to her gown and produced something that almost looked like a one-piece summer dress. Now she went to the Topaz hatch and peered into the passages leading to the other modules. “Is this the whole base? It's about the size of four buses. You spend a whole year here?”
“I think the floor area is bigger than it looks,” said Sohya. “I remember the specifications said three hundred square meters.”
“You must mean the habitable volume. That's three hundred cubic meters,” corrected Cui. “In zero gravity, the walls and ceiling can double as floor space, so volume means something. But here we have gravity, even though it's only one-sixth of Earth's, so the metric we use is floor area. Leaving out shelving and subfloor space, the total area of the base is about 160 square meters.”
“A hundred and sixty meters of floor spaceâ¦Yes, that's enough for a family of three,” said Sohya. “But then again, you have all this equipment.” Sohya was trying to understand the base arrangement in terms of his construction background. That was his mission; his number one goal was to understand Kunlun as a structure.
Cui glanced at the time readout on his wearcom. “Wherever you live, that's home. Space isn't much of a problem. Black Tortoise has everything people need for life.” Cui spread his arms wide toward the space around them. The ceiling was nearly three meters above the floor, the width of the room was three meters, its length nearly fourteen meters. Cui walked along, pointing to various devices along one wall, as Tae and Sohya followed.
“Advanced oxygen generator. Two CO
2
scrubbers. Climate control keeps the base temperature at a constant twenty-four degrees Celsius. Power supply units are connected to the external solar panel array, which provides plenty of power. The water-treatment device lets us recover 60 percent of the water we use. We have 220 different food items and enjoy a varied diet. With an always-on, high-speed comm link with home, we can watch as many movies as we like. That control panel on the wall allows us to control all the important devices on the base. The sleep stations up top provide personal space. And most important of all, we have this.”
Cui pointed to the table around which they now stood, near the north end of the module. It served as a meal table but could be converted for other uses with extension panels. Cui placed both hands on it. “This table is where the three of us gather and socialize as a family. It's important for promoting group harmony.”
Cui's delivery reminded Sohya of a sales pitch for a new housing development, but he was still impressed by the man's sincerity. He decided this was a good opportunity for some questions. “This is such an advanced installation. The structure must be quite something too.”
“The structure?”
“The framework. Let's seeâ¦the insulation. Seismic reinforcement, that sort of thing,” said Sohya.
“Oh, I understand. Of course, very advanced. The pressure hull is comprised of two layers of three-millimeter aluminum alloy over five-millimeter ribs. We've added Whipple panels and a layer of regolith on the exterior to protect against micrometeor strikesâ”
“Hold it. Three millimeters?”
“What about it?”
“Well, I mean⦔ Sohya was nonplussed. On Earth, a metal structure with such thin walls might be usable as a storage unit. Any rigid-frame structure, whether made of wood or steel, required a certain thickness, if only for insulation. For a box frame structure with load-bearing walls, an even greater thickness would be required. Of course, Sohya was well acquainted with monocoque construction in aircraft, cars, and ships, but even so, three millimeters of aluminum skin was just too thin.
“Is that enough? What about heat and cold?”
“Of course, the environment gets very hot,” replied Cui. “The sun is up for fourteen days. It's dark for the same amount of time. During that cycle the outside temperature ranges from 160 degrees Celsius to minus 120 degrees. The outer skin is covered with a heat shield, but that alone isn't enough to keep the inside temperature constant, so we circulate coolant to the hull during the day to maintain constant temperature.”
Sohya remembered the network of pipes next to the outer skin that he'd seen in the air lock.
“You don't have to worry about structural strength either,” Cui continued. “Material strength is proportional to the cross section, but with one-sixth gravity we make do with one-sixth thickness. And there are no moonquakes to worry about.”
“What about the foundation? Where the module contacts the surface.”
“Each module is wedged with rock to prevent rotation, but that's just in case.”
In other words, the modules were just sitting on the regolith. Maybe the rock wedges could be considered a type of mat foundation, but without measures to prevent the modules from settling unequally. Gradually, Sohya realized what sort of structure the base represented. It was nothing more than a temporary installation. He was amazed it had lasted even a year.
“This is a permanent facility. Shouldn't it be built to higher specs?”
“Not practical.” Cui shook his head. “Mass limits apply to everything brought to the lunar surface, you know. Oxygen, water, food, solar panels, and other life-support supplies get first priority. Next are supplies required to carry out our research mission. As far as structural aspects of the base go, the minimum is enough.”
“Of course, when you improve the quality of a building it usually adds more and more weight,” said Sohya.
“Mr. Aomine? Is there something about this base that concerns you?” Cui's eyes narrowed as he regarded Sohya, who was deep in thought.
“Oh, nothing,” Sohya said casually. There was something about Cuiâhe was the tallest and brawniest of the base crewâthat made him difficult to approach. Sohya was beginning to feel uncomfortable around him. It would probably pay to avoid sounding critical.
“If you're satisfied with this orientation to the habitation module, shall we move on?” said Cui, glancing again at his wearcom. He stared at Sohya and Tae. Sohya suddenly realized that Tae, usually so full of curiosity and questions, hadn't said a word during Cui's explanation. She stood with her hands clasped in front, looking down uncomfortably.
“Tae, is there something wrong?” asked Sohya.
“I-I haven't been to the toilet since we got here.”
This was thoughtless of Sohya. The previous night before going to sleep, he'd gone to get an explanation of the toilet's location and how to use it, but Tae had been too shy to bring it up.
“Mr. Cui, is there a toilet?”
“Of course. It's on the other side of that clothes rack.” Tae nearly jumped in the direction Cui pointed. She peeked into the toilet, which was about the size of a tiny closet, and wailed. “The walls are so thin!”
“Don't worry about smells, it's ventilated,” Cui reassured her.
“It's not just smells. I mean, the sound⦔ she murmured feebly. Cui and Sohya had nothing to say. “We'll wait for you in the node,” said Cui. “Call if you need help.”
“Okay.”
The two men passed through the command center on the south side of the module, which was crammed with monitors and control equipment, and entered the Topaz node, the intersection of the four base sections. There they waited. After a few minutes, Tae appeared, her cheeks slightly red. Sohya recalled her expression from the night before, when she was about to remove her space suit. “Did everything go well?”
“Of course! I studied the manual before we got here!” she said heatedly, touching something at her throat. Sohya realized it was a wearcom suspended on a chain. She was absently fingering the tiny keyboard.
Suddenly the node was plunged into darkness. Tae yelped with fear. Sohya reflexively embraced her from behind to shield her. He had had a number of close calls on construction sites, but as his mind raced and he tried to remember the escape route, he suddenly felt a chill run down his spine.
Having put himself and Tae in the hands of the base members, he had forgotten that death was only inches away in this place. There was no escape route. The only way to escape was via the
Chang'e
spacecraft, and Sohya had no idea how to operate it. Iwaki never tired of saying it: keep the worst case in mind at all times. Sohya bit his lip as those words came back to him. He had been careless.
“Cui, where are you? Should we head for the backup vehicle?” Cui should have been right next to him, but when Sohya put out his hand, there was only empty space. Sohya exhaled sharply with frustration and started to go back into the habitation module.
There was a click, and light returned. Cui was leaning into the node from the west module, joining two cables.
“Sorry. One of the power connections came loose.”
“Really? Is that all it was?” asked Sohya.
“Yes. The cables have to be easy to disconnect, in case we need to seal off one of the modules.”
“Sohya?” Tae was trembling against his chest. “Isâis everything all right?”
“It looks that way. A cable just got loose.” He stroked her hair. Cui came back through the hatch.
“We were scared. You could have said something,” said Sohya. Cui looked away. “Really? It was just a minor problem.”
“Does it happen often?”
“Not often, no. Come with me.” Cui checked the time on his wearcom again and turned his back. They followed him uneasily into the next module.
WHITE TIGER, THE
life sciences research module, was comprised of two banks of multilevel racks lined with plastic cases in a variety of shapes and sizes. Some of the cases were brightly illuminated with air lines leading into them. Others were opaque and sealed against the light. Countless tubes and cables snaked among the cases. The room was filled with the hum of an air compressor. It looked just like a familiar business back on Earth. Sohya realized what it reminded him of: a pet shop.
Cui pulled a case down from one of the racks and showed it to them. “A New Zealand rabbit.” Inside the case, a plump rabbit lay curled in a ball.
“Oh, it's cute!” Tae reached for the lid, but Cui stopped her.
“We're keeping it in a germ-free environment.”
“You brought this all the way from Earth?” asked Sohya.
“No, we brought this specimen's grandparents up in the form of fertilized eggs. This is the fourth generation. We want to see how they breed and develop in low-G conditions.”
“It's the real rabbit in the moon,” said Sohya. “Where are her parents?”
“Once they breed, they're no longer needed, so we eat them.”
“Oh noâ¦so that's going to happen to this little one too?” Tae's eyes opened wide. She put her hands together in an attitude of prayer and bowed toward the rabbit. Cui replaced the case and went to another rack.
“These are plants. We cultivate sixteen kinds of edible plants, mainly grains and legumes. We're already harvesting barley as a staple year-round. The aquariums over there contain black tiger shrimp, tilapia, and other aquatic life.”
“You're prioritizing food sources?” asked Sohya casually. Cui frowned slightly.
“Yes, there is that tendency. But of course, we're doing pure science too. Some people have criticized Chinese space exploration as too practical, but that's not at allâ”
Cui was cut off by an electronic beeping from the far side of the module, like an alarm clock. Peng called out, “Damn it, I'm out of time.
Qian shao xia ren
is off the menu for tonight.” “
Qian shao
âyou can make Szechuan shrimp?” Tae called back. After a few moments, Base Commander Peng emerged from behind a worktable half-hidden by one of the racks, scratching his head. “Well, yesâ¦after I dissect the specimens we've raised.”
“I love Szechuan shrimp.”
“I'm sorry, but I've got to move on to my next task, so I won't be able to harvest shrimp today. Cui, can I ask you to look after our guests? I didn't finish the quail and the rhizopus fungi. The seaweed's gone badâyou can discard it.”
“Yes, Commander,” said Cui.
“Carry on then.” Peng spoke into his wearcom. “Beijing Control, Peng is moving to Black Tortoise CO
2
scrubber maintenance.” He strode away. Cui asked Sohya and Tae to wait as he attended to Peng's remaining experiments. Sohya realized why he had not seen Peng since early morning.
“It must be a lot of work to keep all these life science experiments running.”
“It takes up a third of our time. Excuse me,” Cui said as he moved quickly past with a container of seaweed. Sohya and Tae flattened against the wall to let him go by. In a few seconds he was back. He took a bag of something that looked like animal feed from beneath one of the floor panels and began scattering it inside several cases containing quail.
“What a job,” marveled Sohya.