Critical Mass, page 26
The map scrolled across the terrain and Ecklund highlighted a mound of regolith. “Finally, this structure here is an optional human-rated habitat, buried to protect against radiation. I say ‘optional’ because this base will be built and run mostly by teleoperated robots up at Clarke Station, using relay sats now in lunar orbit.”
He looked up at his audience. “Unlike the small lunar bases established by the US and the Chinese near the lunar south and north poles, Morra Base is going to have a sizable footprint—especially with the LEML track. Therefore, it will need to be constructed to withstand regular and fairly serious moonquakes without deforming, and in the case of the mass-driver, must also permit remote realignment and recalibration.”
Tighe frowned. “Moonquakes?”
Balter added, “I was under the impression the Moon was not seismically active.”
Ecklund replied, “Not tectonically, no. However, due to the dry, cold nature of the Moon, asteroid and meteor impacts tend to ring it like a bell—leaving it quivering for quite some time afterward. Then there are so-called deep quakes caused by tidal forces with the Earth. And also dawn quakes that occur as the heat of sunlight expands the Moon’s frigid crust after the two-week-long lunar night.”
Balter muttered, “Crikey . . .”
“But most worrisome are the ‘shallow moonquakes’—caused by crust shifts as the Moon cools. Seismographs placed on the Moon by the Apollo missions measured some at 5.5 on the Richter scale, and they last a long time—typically at least ten minutes. Occasionally longer.”
The team exchanged concerned looks.
Tighe asked, “And we can build this mass-driver to cope with these quakes?”
Ecklund nodded. “Absolutely.”
Chindarkar looked up from her notes. “Bob, at only 10 kilograms per shot, how much mass do you anticipate we’ll be able to launch into lunar orbit over, say, the course of a year?”
“In full operation with 50 megawatts of constant power through superconducting coils—moonquakes and meteor impacts aside—this machine can theoretically fire a 10-kilo cylinder into orbit once every two seconds. That amounts to 432 metric tons every twenty-four hours, about 13,000 tons per Earth month . . .”
The team whistled and Cadot and Lawler exchanged wide-eyed expressions.
“. . . just over 100,000 tons per year, if we factor in one-third downtime for maintenance and malfunctions.” Ecklund looked resolved. “Enough to keep you chemists and engineers busy up there.”
Chindarkar nodded appreciatively as she took notes on a virtual pad. “Excellent. Thank you.”
Ecklund studied the team’s faces. “You need to understand something, folks: lunar mass-drivers like this aren’t a new idea. Engineers have been proposing them to NASA for a long time. Decades—though with Type-II superconducting tape and nitrogen cooling, mine might be the most efficient and reliable. I’m only starting to grapple with the idea that you people may actually build it, but if you do, I will make certain it works. And if we pull this off, it’s going to be more than an architectural achievement—it’s going to alter the trajectory of civilization.”
CHAPTER 21
A Slender Thread
CLARKE STATION POPULATION: 10
DAYS TO RYUGU DEPARTURE: 1,213
Over the next few days, the crew of Clarke Station dug into their work. Jin Han, Priya Chindarkar, and James Tighe closely monitored the various efforts running in parallel because the failure of any one of them could sink the entire project. Passing by Monica Balter at her VR workstation in South Hab, Jin and Chindarkar stopped to watch her remotely pilot a mule spacecraft outside the station. Balter used the robotic arms on the front of the mule to gather solar power satellite components produced by Kerner’s CVD mill and convey them to the supply yard, where they would later be used by SPS-Alpha assembly robots. That is, once they arrived.
Balter’s telepresence skills with the mule appeared modest at best.
Standing behind her, Jin cleared his throat and asked, “Monica, did we allocate you enough building materials?”
“Oh . . .” She paused, still blinded by the VR glasses, but then nodded. “There’s not much margin for error, but if I account for every kilo, we should be okay.”
“Do you think we can still make the May completion date for the satellite?”
She answered, “Yes, I think it’s realistic.”
The master plan was a series of linked projects, and its success depended on the timely completion of each step. Without the power satellite, the mass-driver and regolith harvesting couldn’t work, and without a working refinery at L2, any regolith launched by the mass-driver into orbit couldn’t be transformed into useful materials—which meant they wouldn’t be able to finish building out Clarke Station. That, in turn, would mean they couldn’t bring up the scores of experts they’d need to construct the rescue ship—a ship they would then also not have the materials to build.
So their success would be hanging from a slender thread for the foreseeable future.
Chindarkar asked, “Does your mass estimate factor in repairs and maintenance?”
“There’s a contingency factor, but these SPS-Alpha sats are rather insubstantial. Just a linked collection of hexagonal metal frames that are easy to manufacture. A few station-keeping thrusters and fuel tanks. We’ve got silica and all the equipment necessary to produce the solar panels and thin-film mirrors that concentrate sunlight. I just need the automated assembly robots and the microwave transmitter components—which should arrive soon.”
Jin said, “Good. We are relying on your satellite to power everything on the lunar surface. So if you foresee any delays, let us know immediately.”
She nodded. “Will do, Captain.”
Meanwhile, Sofia Boutros, the chemist, had set up the beginnings of a lab against the South Hab’s anti-spinward bulkhead on H2 level. There, she and several others connected an exhaust hood to a preexisting duct and constructed steel countertops and lockable cabinets. Soon she was able to produce chemical compounds critical to life aboard the station.
Boutros began by using monomer feedstock and equipment brought up from Earth to formulate synthetic fibers, which she then fed into a small textile printer that had been sent up weeks earlier to produce fabric in several shades of mauve. The rest of the team stretched this fabric over printed polymer wall panels, which they then affixed to the walls of their quarters on H1. Aside from privacy, the panels alleviated the maddening echo in the steel-walled hab—at least on the first level. They then did the same for North Hab, even putting the Space Force observers to work. For a while the smell of new fabric prevailed over the fetid water in the habs.
However, the station’s plumbing issues continued to grow worse. Since Jin Han and Sevastian Yakovlev were both engineers, they worked on the problem with mission control—but this pulled them away from urgent construction work on the station’s external regolith refinery. Almost immediately putting them behind schedule.
Water line clearing procedures didn’t fix the plumbing and, worse, caused a new problem: now turning off sink faucets triggered “water hammer,” a pounding noise that echoed throughout the hab and shook pipes. It was caused by the mass of a moving water column suddenly slamming against a closed valve. Unchecked, it could do serious damage to the pipes.
Jin and Yak stared up at the water lines running along the exterior of South Hab’s elevator tube, toward the station core.
Yak shook his head. “Ancient Romans had indoor plumbing. How can we not have this on a space station?”
“This is a new environment.” Jin studied where the pipes entered the compartment ceiling. “On the Konstantin, our water supply was local to each hab, but here the water lines are coming and going from the core—moving through different levels of micro- and spin-gravity.”
“So designers messed up?”
“Possibly. Maybe it’s just a blockage in the pipes, but either way, we need to fix it. Otherwise, this could get deadly serious.”
Yak thought for a moment. “You refer to station stability.”
“Yes. If the water levels get too imbalanced, and the mass equalization system cannot compensate, Clarke Station could start to wobble like a broken wheel. It could wreck the place, and we would not be able to easily evacuate.”
Yak nodded to himself. “I will locate cause of this problem.”
The next morning Jin climbed the spiral staircase into the open H2 level, and out of the corner of his eye spotted a shimmering object. He glanced up and saw a sizable water drop floating in the air 5 meters above the conference table and moving anti-spinward at several kilometers per hour. It resembled a translucent insect.
Alarmed, he followed it beyond the elevator column, heading toward Boutros’s lab.
Tighe’s voice called from behind him. “Where the hell is that coming from?”
“I do not know.” Jin followed the droplet, with Tighe falling in behind him. They soon watched it splash into a wet spot that had already formed on the compartment’s back, or anti-spinward, bulkhead.
Jin looked toward the LED lights mounted in the hull far overhead. “It is coming from up there.”
Tighe craned his neck alongside him. “We’d better find out from what. Before it gets worse.”
* * *
—
After another hurried consultation with mission control and an examination of the South Hab ceiling, it was determined that the dripping water was condensation from human activity—breathing, bathing, and so on—and also pressure and temperature differences between levels H1 and H4. This was expected, but the equipment to catch and process the runoff was not yet on station. Until it arrived, the crew would need to regularly wipe down the anti-spinward wall in both habs.
The fact that this was a surprise to the crew did not ease Jin’s mind.
The next morning Tighe stood on the lab counter, swabbing the bulkhead wall with a makeshift mop, and glanced back toward Chindarkar at the conference table. “Priya. Have you seen Ramón?”
“I’m guessing he’s in one of the server rooms.”
“I know we all have work to do, but everyone needs to pitch in with these hab chores, too. Ramón needs to be part of the team, not doing his own thing.”
After mopping up, Tighe went through the system logs, overlaying Marín’s RFID tag movements through the station since he’d come aboard a few days ago. It quickly became apparent that Marín moved only between the new server room here in South Hab and the computer core adjacent to the docking hangar. In fact, Marín either stayed up all hours, or he actually slept in the South Hab server room.
Tighe showed the logs to Chindarkar and Jin. “Lukas clearly has plans for this Cislunar Commodity Exchange of his, and his guy is executing them. We need to understand what those two are up to before it becomes our problem.”
Just then Jin noticed Major Lawler exit the elevator. Lawler was uncharacteristically grim-faced and beelined for the trio at the conference table. “Don’t look now, but here comes our minder.”
Lawler nodded. “Captain Jin. There’s a matter of some urgency we need to discuss.”
“What is it, Major? We’re in a meeting.”
“I just received word that CSpOC is tracking a radar contact on a trajectory that will bring it to EM-L2 within five days.”
Tighe frowned. “CSpOC?”
“The Combined Space Operations Center at Vandenberg. They track all objects in cislunar space.”
Jin asked, “Do they know what the contact is?”
“Affirmative. It’s a Chinese-crewed spacecraft. A seven-man capsule. Launched two days ago from Jiuquan. It was in LEO but did a TLI as it passed through the lunar antipode.”
Tighe said, “Can you translate that into English?”
“It’s now headed up here.”
“Shit.”
Chindarkar asked, “Do they know what’s on it?”
“Negative.”
“We agreed to the presence of Chinese observers, but they were supposed to arrive via our lunar cycler. For security reasons.”
Lawler nodded. “They seem to have other ideas.”
Jin said, “They could be traveling to their own lunar space station.”
“If so, this is a highly inefficient trajectory, and their station has capacity for just four crew. Two are already in residence there.”
Tighe sighed. “And this incoming craft is a seven-man capsule? Christ. What if they’re armed?”
Chindarkar said, “But seven people in a small capsule for a week? That seems unlikely.”
Jin said, “We need to get Lukas on the line. It is time for him to earn his keep down there on Earth . . .”
* * *
—
“I thought we made an agreement with the Chinese, Lukas. Their observers were scheduled to come up on the lunar cycler next month.”
Gathered around the conference table was the entire Gold Team, Yak, and Majors Lawler and Cadot. An augmented-reality video screen displayed Lukas Rochat sitting in his office back on Earth.
Rochat said, “True, but the PLA says it’s unfair for an entire month to go by while two US observers are already on the station.”
“How many people are in that capsule?”
“They claim it’s just two. One taikonaut and one cosmonaut, and there’s no service module attached, only a propulsion module.”
“A Russian? So these are both China’s and Russia’s observers?”
“If they’re telling the truth—which we can’t verify—and we didn’t have an opportunity to scan them or their baggage for weapons. So we have no idea what they’re bringing up there. The entire capsule could be packed with explosives, for all we know.”
Lawler said, “That seems unlikely, given that there are US military personnel on this station.”
Jin asked, “Do you know the identities of the capsule crew?”
Rochat checked a document. “A Colonel Evgeni Voloshin . . .”
Yak responded, “I do not know him.”
“And . . . a Colonel Fei Liwei.”
Tighe looked up. “Where do I know that name from?”
Jin answered. “He was one of the taikonauts who rescued us in LEO when we came back from Ryugu.”
“Oh yeah. And also stole our ship.”
Yak snorted. “Salvaged, he would say.”
“Maybe he wants to ‘salvage’ Clarke Station, too.” Tighe turned to Jin. “You know this prick. What’s he up to?”
“He is a party man.”
“Sounds fun.”
Jin gave Yak the side-eye. “I meant political party.”
Tighe spoke to Rochat. “Tell them we won’t allow their capsule anywhere near this station.”
“They claim Clarke Station was built in violation of international law and demand the right to board it.”
“Who put them in charge? Tell them it’s a free universe.”
Rochat replied, “J.T., a response like that is likely to precipitate an international incident. More importantly, they claim to have life support sufficient for only eight days. Not enough for a return to Earth.”
“Oh, that’s convenient. What a load of horseshit.”
Chindarkar said, “We can’t take that chance.”
Jin leaned in. “Lukas, you negotiated this international observer deal. Tell them they must comply with its terms.”
“Our deal did not explicitly state the means by which the observers would reach the station, only that they would be permitted on the station after submitting to a thorough search for contraband.”
Jin glared. “You didn’t restrict outside spacecraft from docking here?”
“We did. There’s a 200-meter exclusion zone. However, they haven’t violated it yet.”
Tighe folded his arms. “And we can’t let them violate it either. Or we’ll soon be up to our eyeballs in ‘visitors.’ ”
The group sat in silent contemplation for several moments.
Chindarkar said, “I may have an idea how to resolve this . . .”
* * *
—
Five days later Tighe sat in a telepresence workspace on Clarke Station, his crystal glasses in VR mode as he operated a humanoid Talos robot, which was strapped into a jump seat inside a transit craft a kilometer away. The vessel glided toward a Chinese space capsule and propulsion unit that had recently arrived in their vicinity.
Tighe could hear a voice speaking in Mandarin on an agreed-upon hailing frequency. This was followed by a transmission in accented English. “Unidentified station, this is Jiuquan-five-nine. Do you read? Repeat: unidentified station, this is Jiuquan-five-nine. Do you read?”
Tighe spoke to no one in particular. “Give me a break. They know our station’s name.”
Jin’s voice responded in English close by Tighe’s real-life workstation. “Jiuquan-five-nine, this is Clarke Station. We copy you. Transit-02 spacecraft is now on final approach and will autodock with your forward hatch. Maintain your present position.”
After a pause, the voice came back in Mandarin only.
In his VR headset, Tighe looked around the mostly empty transit spacecraft. Very little had changed inside the vessel over the last month, other than the addition of first-aid kits and emergency breathing apparatuses. Otherwise it looked as Spartan as ever. After a few minutes he heard a klunk sound, and then noticed his robot lurch slightly before locking bolts sounded in the transit craft’s passenger compartment.
Jin’s voice nearby said, “Transit-02 docked.” A pause. “Good seal. Stand by to be boarded, Jiuquan-five-nine.”
