“Like a scarfed nozzle?”
“Exactly. When we fire the main propulsion it will give us an off-axis thrust. If the scarf is oriented correctly, it will have tremendous control authority.”
“Maybe too much,” Dinah said. “We’ll end up overcorrecting.”
“One thing at a time,” Jiro said. “We scarf the nozzle, we do a little correction, we scarf it the other way, we kill the rotation. It might take several repetitions. It can be done. I have been modeling it.”
Dinah pulled herself into position before her triptych of flat-panels, and began opening windows, checking on the activities of her menagerie of robots: some sunning themselves on the outside to soak up power, others sipping juice from the reactors, some mining propellant for the next burn, others mending the nozzle. The latter group, mostly Nats, would be responsible for the nozzle-sculpting program. Until now, having an asymmetrical nozzle, delivering thrust at an off angle, had been a problem to be avoided, not a feature to be encouraged. Jiro had emailed her some diagrams of what the nozzle bell would need to look like. The alterations were surprisingly minor. In an engine that produced that much power, a little bit of off-axis thrust went a long way. “When’s our next perigee?” she asked.
“We just went through one. So, about eight hours from now.”
THE PARAMOUNT DUTY OF THE CLOUD ARK’S COMMANDER—SO IMPORTANT that Markus had broken character and described it to Ivy as “sacred”—was to stay on top of the Bolide Scan, which was a feed of information synthesized out of all of Izzy’s long-range radars and optical telescopes. A disproportionate number of GPop members devoted their lives to managing this, or to maintaining the equipment used to produce it. Because the stream of data was continuous, it needed to be broken down, for the consumption of someone like Markus or Ivy, into reports that showed up on their screens at regular intervals. A Triurnal Bolide Scan was issued at the top of each shift: dot 0, dot 8, and dot 16. Ivy read one of them when she woke up, another in the middle of her “afternoon,” and the third just before going to sleep. Each of these summarized what was known about bolides that might come near them during the next eight hours, and made recommendations as to what maneuvers the Cloud Ark should execute in order to avoid them. Typically they made small burns several times a day for this purpose. The policy was “default go,” which meant that the maneuver would be promulgated to the Cloud Ark via Parambulator, and carried out automatically, unless the commander vetoed it. The only reason this was ever likely to happen was in cases where two dangerous rocks were headed their way at about the same time and they needed to make a decision. Such events had occurred twice during the Hard Rain so far, but they had been simulated and war-gamed hundreds of times before that. The name of the game was to avoid getting cornered.
To be detected eight hours in advance, a bolide had to be pretty big. Smaller ones came along all the time, and weren’t picked up on the radars until minutes or even seconds before collision. Accordingly, smaller reports were issued at the top of each hour, listing all noteworthy rocks that had been detected during the last sixty minutes. This covered most of them, so the commander—or whoever covered for her while she was sleeping—could discharge most of her responsibilities in re the Bolide Scan by dropping everything else she was doing at the top of each hour and reading it. From time to time, however, they would become aware of a “hot rock” or “streaker” that had surprised them by coming in from a weird angle, or at unusually high speed, and then the commander would be notified immediately so that an alert could be issued and evasive action could be seen to. The Streaker Alerts combined elements of the small-town midwestern tornado siren with the red alert from Star Trek. All sleeping people were awakened, all nonessential personnel were evacuated from the larger tori, which were considered most vulnerable, and hatches were closed between different sections, in case of a breach. Similar precautions were taken by the Arkies. Arklets were, of course, more vulnerable to bolide strikes, but they were also more maneuverable. As the hot rock drew closer and its orbital parameters were determined more precisely, the data would be fed to Parambulator. Any arklets in danger of being hit would be identified, and a collective solution would be calculated that would enable them to move into safer trajectories without banging into anyone else. These events happened, on average, between one and two times a day, but as always the devil was in the statistical details. They had once gone three days without a single streaker. On another occasion they’d had five of them within a twelve-hour period. The first of these events had caused an upwelling of chatter on Spacebook to the effect that the powers that be were overstating the threat in order to cow the Arkies into submission, and the second had generated a hard-hitting blog post from Tav Prowse calling the GPop on the carpet for systematic incompetence.
It was in the wake of such an alert, while cleaning up her desktop of postaction chatter, that Ivy’s attention was drawn to a post that had just come up on Tav’s blog: an interview with Ulrika Ek.
“Ulrika has a lot to learn about bloggers” was Ivy’s verdict, after she’d finished reading it. She shook her head. “You’d think she of all people would know—she’s been through PR training.”
These remarks were delivered to a Banana that had been slowly repopulating itself, during the last few minutes, with people who had been called away on other duties during the Streaker Alert. Tekla was the last to arrive, bringing Tom Van Meter and other members of Markus’s security detail in her wake. Luisa and Sal were already present in the room. Doob had just texted his regrets, explaining that he needed to crunch some numbers about what had just happened.
“She probably dropped her guard,” Luisa suggested, “thinking she was just chatting informally.”
“You’ve read it then?”
“I scanned it.”
“Referring to what?” Tekla asked.
“Ulrika made a few off-the-cuff remarks about swarm theory, and which strategies we might wish to pursue in the future, and Tav is blowing them up into a cause célèbre,” Ivy said.
“What if anything would you like to do about it?” Sal asked.
“Nothing,” Ivy said. “Look, the longer this thing with Ymir continues, the more anxiety people have about the Big Ride. Every time a hot rock comes in it juices up that anxiety for a little while. Well, either it’ll work or it won’t. If it doesn’t work then we have very little choice anyway—we have to Dump and Run.”
Sal nodded. “But if it does work, it’ll change everything about the way people think.”
Ivy nodded. “Yeah. And I am growingly certain that it will. Even if the scarfed nozzle gambit fails, we still have that MIV we can send out as a backup plan. I think that in a week we’ll have a successful rendezvous with Ymir and we’ll be prepping for the Big Ride.”
Ivy made a gesture indicating that the new arrivals should find places for themselves around the table. “Which brings me to the topic of this meeting,” she continued. “We know what J.B.F.’s plan is. She’s recruiting some number of Arkies willing to strike out on their own. The general scheme seems to be that they’ll get a few arklets stocked with provisions for a few weeks’ journey. Then, on a signal, they’ll break away from Izzy and make burns that will take them to a higher orbit. An orbit that we can’t reach without expending a lot of propellant. We don’t know what their long-term plan is—or if they even have one—but I think Julia is basically playing the odds that these people will survive long enough to send back messages saying ‘Come on in, the water’s fine!’ and encourage other Arkies to follow suit. They all know that they can’t really be pursued once they have departed the swarm. Membership in the Cloud Ark is, under the current state of affairs, voluntary.”
“I infer you mean to change that?” Luisa asked drily, casting her gaze over Tekla and the members of the squad.
“They can’t make a break for it without hoarding certain critical supplies,” Ivy said. “We can’t allow people to just ransack our storage facilities for whatever the
y want. And we have clear evidence that this has been happening. There’s traffic on Spacebook about where to look if you want to score a box of fresh batteries or scrubber cartridges. So, our basic approach to this is going to be simple. We’ve identified the worst offenders, where hoarding is concerned. I’m going to make an announcement in an hour, explaining how the Cloud Ark Constitution works when it comes to theft of public supplies, and I’m going to offer a twenty-four-hour amnesty during which anyone can turn in stuff that they have been hoarding. As soon as that time is up, Tekla and her team are going to move on one arklet that we know is being used as a storage dump for contraband, and they are going to restore order. And then Sal will step in, as prosecutor, and take whatever action he deems justified.”
“How can you put people in jail when they are already confined to tin cans?” Luisa asked. “How can you fine them when there is no money?”
“We will have to evolve solutions as we go,” Sal said.
Tekla stared him down, then drew her thumb across her throat.
“WELL, THAT SEEMS DEFINITIVE,” JULIA SAID.
She and Spencer Grindstaff were hovering in the middle of the White Arklet. Drifting near them was a laptop whose speakers had been playing the audio feed from the Banana. They could hear the sounds of the meeting breaking up, and people separating into smaller conversations as they moved out of the room. Spencer pulled it closer and whacked the volume button a few times to mute the sound.
“As I said before: hook, line, and sinker.”
“Unless,” Julia said, “they are somehow aware of the fact that we have surveillance on the Banana, and everything we just heard was a sort of radio play staged for our benefit.”
Spencer beamed. “Now, that is paranoid! I thought I had it bad, but—”
“Just kidding,” Julia said, a little too quickly. “This is actionable, Spencer. I believe we are justified in taking everything we just heard at face value. Which means I am comfortable giving good news to the Martians. Are they ready?”
“Yes, they’ve been waiting,” Spencer said, and thumbed out a text message to summon them.
The Martians all had to come via the same hamster tube, so it took a few moments for the core members of the first human expedition to the Red Planet to filter in: Dr. Katherine Quine, whose professional role was obvious; Ravi Kumar, who would be the expedition’s commander; Li Jianyu, who would act as a general science officer; and Paul Freel, an American MIV expert, the head engineer. They, as well as a score of other Arkies waiting in the wings, had sworn an oath that they’d not spend the rest of their lives sealed up in tin cans, but would walk on the surface of Mars or die in the attempt. In their wake came several other members of Julia’s “staff.”
Julia opened the meeting with a few words of greeting and a solemn announcement to the effect that the Mars mission was a go. Once the ensuing round of zero-gee high fives and embraces had trailed off into an awkward silence, she singled out Paul Freel. “Paul, no doubt you’ve briefed these others on the very latest while you were so patiently cooling your heels, but might I know what has been going on with the MIV?”
“Of course, Madam President. As you know, they’re trying to stabilize Ymir with—”
“A Rube Goldberg scheme in the form of an ice sculpture. Yes, I know about that.”
Paul chuckled, showing a lot of gum. “Not surprisingly, the powers that be are a little nervous about that and so word came down from on high that we ought to be preparing a backup plan, so we can go pull Ymir’s fat from the fire if need be. Well. That couldn’t be better, from a Martian point of view! As you know, we have been planning this mission for years. After Zero, I kept it going as a side project all through the development of the MIV program, and we managed to grease it in as one of the use cases.”
“Use cases?”
“One of the hypothetical uses to which the MIV kit might eventually be put,” Spencer explained.
“Basically it just gave us an excuse to include a few components, like throttleable landing engines and aeroshield material, that might not have made it in otherwise,” Paul went on. “So, stabilizing Red Rover’s design has been a piece of cake.”
“Red Rover?”
“Yeah, that’s what we’re calling her.”
“I would like to propose something a little more suggestive of a higher purpose,” Julia said. “Spearhead or some such thing.”
This led to an uneasy silence terminated by Camila, who said, “I’ll draw up a list of options and submit it to you right away, Madam President.”
“Thank you, Camila. You understand, Paul, that this mission will have symbolic as well as scientific value, and we want to send the right message to the other Arkies so that they will feel inspired to follow in her wake.”
“Of course! Consider it a working title only,” Paul said. “A code name.”
“It’s not even good as a code name,” Spencer pointed out, “because anyone can—”
“Let’s move on,” Julia said. “You were talking, Paul, about the design.”
“Done. It took, like, a man-day. We just had to make a few tweaks to a preexisting use case to reflect the materials and supplies we actually had on hand.”
“Excellent.”
“But a design is not a ship, of course,” Paul continued, “and until a couple of days ago it would’ve been pretty darn hard to put the actual propulsion system together without bringing down the wrath of Ivy!”
“That is not a phrase calculated to strike fear into the heart of anyone except those most worshipful of her authority,” Julia remarked, speaking with the gravity that could only be summoned by one who had recently used nuclear weapons on live targets.
Paul cackled. “You know what I’m saying, though—everything happens in a fishbowl here! So, you can imagine the grin on my face when we got the order to begin assembling the Ymir rescue MIV.”
“Are the specifications similar?”
“Similar enough. They can both use the same main engine. The thruster packages, the control systems, life support—all of that stuff is completely standardized; it doesn’t change from one use case to another, it’s just a matter of punching different parameters into the code. It’s just a config file!”
Seeing that Julia didn’t necessarily know what a config file was, Spencer put in, “They can essentially download the DNA, if you will, of Red Rover, or whatever we end up calling it, into the Ymir rescue vehicle with a few keystrokes.”
Satisfied with that, Julia asked, “What of the arklets? The heptad and the triad?”
“Well, they’re already functional, independent space vehicles. Way more than enough space for twenty-four Martians and their vitamins. Obviously, we’ve been stocking up,” Paul said, waving his hands around at the bags of food and other supplies crowding the White Arklet.
“Yes,” Julia said, “but the critical part of the operation is going to be moving them from their default positions in the swarm—which will seem unremarkable as far as Parambulator is concerned—to the propulsion stack that you have been assembling. And that’s going to make a hell of a stink, is it not?”
The smile on Paul Freel’s face became a bit frozen. “We could just go for it,” he said.
“I have a workaround,” said Spencer Grindstaff. “I think we can make this happen. A Streaker Alert is all we need. It’ll go down tomorrow.”
“How do you know there’s going to be a Streaker Alert?”
“Such an event is nothing,” Spencer said, “other than a particular configuration of bits.”
DINAH HAD BEEN DREAMING OF MARS.
As an asteroid miner, she had never been that interested in the distant and inhospitable Red Planet. The politics of the pre-Zero space exploration world had obliged her to show skepticism, even disdain toward those who wanted to go there and to build colonies and terraform the planet. Mars colonists were siphoning attention and resources away from the asteroid miners, who wanted to use easier-to-get resources to make muc
h more human-friendly habitats: space colonies, rotating to provide full gravity, with plenty of water and fresh air.
In any event, it had been a dead issue for two years. But that didn’t prevent Mars from showing up in her dreams, and now infiltrating her daydreams. Almost three years had now gone by since she had walked on the surface of a planet, looked up into a sky, seen a horizon. Intellectually she knew that death would take her, sooner or later, before she did any of those things again. She and everyone else in the Cloud Ark would live out their lives in environments resembling bomb shelters, hospital basements, and research labs. The best they could hope for was to look out a small window at the starry sky. The view of the blue, green, and white Earth had once provided fascination and solace. The orange ball of fire they now circled was such a disagreeable sight that most people actively avoided looking at it. No one was ever going back there. For those who still aspired to go for a walk before dying of old age, Mars was the only hope, be it ever so impractical. People had been talking about it on Spacebook, and on some of the blogs that had been cropping up on the Cloud Ark’s miniature Internet. Before the loss of New Caird had severed Ymir’s data link to the Cloud Ark, some of it had trickled through to her tablet, and Dinah read it in idle moments.
At least she had some idle moments now. Since the decision to try the scarfed-nozzle approach, they had executed two burns, about twenty-four hours apart, each with a slightly different configuration of the ice nozzle: a canted lip, constructed by the Nat swarm, projecting almost imperceptibly above the aft surface of the shard and bending the torrent of steam slightly. The first of those burns had gotten them spinning the way they wanted to go, though “spinning” might be too strong a word for a rotation that took the better part of a day. During that day the Nats had decamped to the other side of the nozzle’s rim and built a lip there. The second burn, then, had stopped the rotation that the first one had started, and brought them close enough to their desired attitude that the surviving thrusters could handle the details.
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