by Cixin Liu
Then came an opportunity for her to leave chemical rockets behind. The United Nations began to create all sorts of agencies related to planetary defense. Unlike UN agencies from the past, these new agencies reported directly to the PDC, and were staffed by experts from various nations. The Chinese aerospace system sent many people to these agencies. A high-level official offered Cheng Xin a new position: Aide to the director of the Technology Planning Center for the PDC Strategic Intelligence Agency. Humanity’s intelligence-gathering work against the Trisolarans had so far focused on the ETO, but the PDC Strategic Intelligence Agency, or PIA, would focus their efforts directly on the Trisolaran Fleet and the home world of Trisolaris itself. They needed people with strong backgrounds in the technical aspects of aerospace technology.
Cheng Xin took the job without hesitation.
The PIA Headquarters was located in an old six-story building not far from the UN Headquarters. Dating from the end of the eighteenth century, the building was thick and well-built, like a solid block of granite. When Cheng Xin entered it for the first time after her trans-Pacific flight, she felt a chill, as though entering a castle. The place wasn’t at all what she had expected from an intelligence agency for the whole world; it reminded her more of a place where byzantine plots were hatched through whispers.
The building was mostly empty; she was among the first to report for duty. In an office full of unassembled furniture and just-unsealed cardboard boxes, she met her boss, PIA’s Technology Planning Center director.
Mikhail Vadimov was in his forties, muscular, tall, and spoke English with a heavy Russian accent. It took a few moments before Cheng Xin even realized that he was speaking English. He sat on a cardboard box and complained to her that he had worked in the aerospace industry for more than a dozen years and had no need for any technical assistance. Every country was eager to fill the PIA with its own people, but much less willing to give cold, hard cash. Then he seemed to realize that he was talking to a hopeful young woman who was growing rather dejected from his speech, and tried to comfort her by saying: “If this agency manages to make history—a big possibility, even if it probably won’t be very good history—we two will be remembered as the first to show up!”
Cheng Xin was cheered by the fact that she and her boss had both worked in aerospace. She asked Vadimov what he had worked on. He carelessly mentioned a stint on the Buran spacecraft; then that he’d served as the executive chief designer for a certain cargo-carrying spaceship; but after that, his explanations turned vague. He claimed that he had done a couple of years in diplomacy, then entered “some department” that “did the same kinds of things we do now.”
“It’s best if you don’t probe too much into the employment histories of your future colleagues, okay?” Vadimov said. “The chief is here also. His office is upstairs. You should swing by and say hi, but don’t take up too much of his time.”
As soon as Cheng Xin walked into the PIA chief’s spacious office, she was greeted by the strong smell of cigar smoke. A large painting hung on the wall. A leaden sky and the dim, snow-covered ground took up most of the painting; in the distance, where the clouds met the snow, a few dark shapes lurked. A closer examination revealed them to be dirty buildings, most of them one-story clapboard houses mixed with a few European-style houses with two or three stories. Based on the shape of the river in the foreground and other hints in the geography, this was a portrait of New York at the beginning of the eighteenth century. The overwhelming impression given off by the painting was coldness, which Cheng Xin thought fit the person sitting under the painting rather well.
Next to the large painting was a smaller picture. The main subject in the painting was an ancient sword with a golden cross guard and a bright, shining blade, held in a hand enclosed in bronze gauntlets—only the forearm was shown. The hand was lifting the sword to pick up a wreath woven from red, white, and yellow flowers floating over the water. In contrast to the larger painting, this picture was bright and colorful, but it nonetheless radiated eeriness. Cheng Xin noticed that bloodstains covered the white flowers in the wreath.
PIA Chief Thomas Wade, an American, was far younger than Cheng Xin had expected—he looked younger than Vadimov. He was also more handsome, with very classical features. Later, she would conclude that the classical appearance came mostly from Wade’s expressionless face, like a cold, lifeless statue transplanted out of the cold painting behind him. Wade didn’t look busy—the desk in front of him was completely empty, with no sign of a computer or paper documents. He glanced up as she entered, but returned to contemplating the cigar in his hand almost right away.
Cheng Xin introduced herself and expressed her pleasure at having a chance to study from him, and continued until Wade lifted his eyes to look at her.
Cheng Xin thought she saw exhaustion and laziness in those eyes, but there was also something deeper, something sharp that made her uncomfortable. A smile appeared on Wade’s face, like water seeping out of a crack in the frozen surface of a river; there was no real warmth, and it didn’t relax her.
She tried to respond with a smile of her own, but the first words out of Wade’s mouth froze her face and entire body. “Would you sell your mother to a whorehouse?” Cheng Xin shook her head no, but she wasn’t even trying to respond to the question; she was terrified that she had not understood what he said. But Wade waved at her with his cigar. “Thanks. Go do what needs to get done.”
After she told Vadimov what had happened, Vadimov laughed. “That’s just a line that used to be popular in our... trade. I heard it started back during the Second World War. Veterans would use it as a joke on novices. The point is: Our profession is the only one on Earth where lies and betrayal are at the very heart of what we do. We have to be... flexible when it comes to commonly accepted ethical norms. PIA is formed from two groups of people: Some are technical experts like you; others are veterans of the various intelligence agencies in the world. These two groups have different ways of thinking and acting. It’s a good thing that I’m familiar with both and can help you adjust to the other.”
“But our enemy is Trisolaris. This is nothing like traditional intelligence.”
“Some things are constant.”
Over the next few days, other new PIA staff members reported for duty. Most of them came from countries that were permanent members of the PDC.
They were polite to each other, but there was no trust. The technical experts kept to themselves and acted as if they were on guard against theft every minute. The intelligence veterans were gregarious and friendly—but they were constantly on the lookout for something to steal.
It was just like Vadimov had predicted: These people were far more interested in spying on each other than gathering intelligence on Trisolaris.
Two days after Cheng Xin’s arrival, PIA held its first all-hands meeting, even though not everyone had shown up yet. Other than PIA Chief Wade, there were three assistant chiefs: one from China, one from France, and one from the United Kingdom.
Assistant Chief Yu Weiming spoke first. Cheng Xin had no idea what kind of work he had done in China—and he had the sort of face that took multiple meetings to remember what he looked like. Fortunately, he didn’t engage in the habit—common among Chinese bureaucrats—of giving long, meandering speeches. Though he was just repeating platitudes about the PIA’s mission, at least he spoke succinctly.
Assistant Chief Yu said that he understood that everyone in the PIA was sent by their own country, and so they had dual loyalties. PIA didn’t demand, and didn’t even hope, that they would place their loyalty to the agency above their duties to their own nations. However, since the PIA’s task was the protection of the entire human race, he hoped that everyone present would at least try to balance the two appropriately. Considering that the PIA was going to work directly against the Trisolaran threat, they ought to become the most united of the new agencies.
While Assistant Chief Yu was giving this speech, Cheng Xin noticed th
at Wade was kicking the table legs and slowly maneuvering his chair away from the conference table as though he didn’t want to be there. Later, whenever anyone asked him to say a few words, he shook his head and refused.
Finally, after everyone who wanted to make a speech had done so, he spoke. Pointing at the pile of boxes and fresh office supplies in the meeting room, he said, “I’d like the rest of you to take care of these matters on your own.” Apparently, he was referring to the administrative details of getting the agency up and running. “Please don’t take up my time or theirs”—here he pointed at Vadimov and his staff. “I need everyone in the Technology Planning Center with experience in spaceflight engineering to stay. The rest of you are dismissed.”
About a dozen people remained in the now much less crowded conference room. As soon as the heavy oak doors closed, Wade dropped his bomb. “The PIA must launch a spy probe at the Trisolaran Fleet.”
The stunned staff members looked at each other. Cheng Xin was surprised as well. She had certainly hoped to get to substantive technical work quickly, but she hadn’t expected such directness or speed. Considering that the PIA had just been formed and there were, as yet, no national or regional branches, it seemed ill-equipped to take on big projects. But the real shocker was the boldness of Wade’s proposal: The technical challenges and other barriers seemed insurmountable.
“What are the specific requirements?” asked Vadimov. He was the only one who seemed to take Wade’s announcement in stride.
“I’ve consulted with the delegates of the permanent members of the PDC in private, but the idea hasn’t yet been formally presented. Based on what I know, the PDC members are most interested in one specific requirement—and this is something that they won’t compromise on: The probe must achieve one percent of lightspeed. The permanent members of the PDC have different ideas about other parameters, but I’m sure they’ll come to some compromise during formal discussions.”
An expert from NASA spoke up. “Let me get this straight. Given those mission parameters, and supposing we only worry about acceleration and provide no way for the probe to decelerate, the probe will take two to three centuries to reach the Oort Cloud. There, it will intercept and examine the decelerating Trisolaran Fleet. Forgive me, but this seems a project better reserved for the future.”
Wade shook his head. “With those sophons zipping about at lightspeed, spying on us constantly, and completely blocking all fundamental physics research, it’s no longer certain that we’ll make significant technological progress in the future. If humanity is doomed to crawl at a snail’s pace through space, we’d better get started as soon as possible.”
Cheng Xin suspected that Wade’s plan was at least partly motivated by politics. The first effort by humanity to make active contact with an extraterrestrial civilization would enhance the PIA’s status.
“But given the current state of spaceflight technology, it will take twenty, maybe thirty thousand years to reach the Oort Cloud. Even if we launch the probe right now, we won’t have gotten very far from Earth’s front door by the time the Trisolaran Fleet arrives in four hundred years.”
“That is precisely why the probe must achieve one percent of lightspeed.”
“You’re talking about boosting our current maximum speed a hundredfold! That requires a brand-new form of propulsion. We can’t achieve that kind of acceleration with current technology, and there’s no reason to expect a technical breakthrough within the foreseeable future. This proposal is fundamentally impossible.”
Wade slammed his fist down on the table. “You forget that we now have resources! Before, spaceflight was merely a luxury, but now it’s an absolute necessity. We can ask for resources that far exceed what was imaginable before. We can throw resources at this problem until the laws of physics bend. Rely on brute force if you have to, but we must accelerate the probe to one percent of lightspeed!”
Vadimov instinctively looked around the room. Wade glanced at him. “Don’t worry. There are no reporters or outsiders anywhere near here.”
Vadimov laughed. “Please don’t take offense. But saying we want to throw resources at the problem until the laws of physics bend is going to make our agency the laughingstock of the world. Please don’t repeat it in front of the PDC.”
“I already know you’re all laughing at me.”
Everyone held their tongue. The staff just wanted the meeting to be over. Wade looked at everyone in turn, then returned his gaze to Cheng Xin. “No, not everyone. She’s not laughing.” He pointed at her. “Cheng, what do you think?”
Under Wade’s keen gaze, Cheng Xin felt as if he were pointing a sword at her, not a finger. She looked around helplessly. Who was she to talk?
“We need to implement MD here,” said Wade.
Cheng Xin was even more baffled. MD? McDonald’s? Doctor of medicine?
“But you’re Chinese! How can you not know MD?”
Cheng Xin looked at the other five Chinese in the room; they looked just as confused.
“During the Korean War, the Americans discovered that even common Chinese soldiers taken as prisoners seemed to know a lot about their own field strategies. It turned out that your commanders had presented the battle plans to the troops for mass discussion, hoping thereby to find ways to improve them. Of course, if you become Trisolaran prisoners of war in the future, we don’t want you to know that much.”
A few of those present laughed. Cheng Xin finally understood that MD meant “military democracy.” The others in the conference room enthusiastically supported Wade’s proposal. Of course, these elite experts didn’t expect a mere technical aide to have any brilliant ideas, but they were mostly men, and they thought that by giving her a chance to talk, they would have a perfect excuse to appreciate her physical attributes. Cheng Xin had always made an effort to dress conservatively, but this sort of harassment was something she had to deal with constantly.
Cheng Xin began: “I do have an idea—”
“An idea for bending the laws of physics?” The speaker was an older Frenchwoman named Camille, a highly respected and experienced consultant from the European Space Agency. She looked at Cheng Xin contemptuously, as though she didn’t belong in the room.
“Well, more like getting around the laws of physics.” Cheng Xin smiled at Camille politely. “The most promising resource at our disposal is the stockpile of nuclear weapons from around the world. Without some technical breakthrough, these represent the most powerful sources of energy we can launch into space. Imagine a spaceship or probe equipped with a radiation sail, similar to a solar sail: a thin film capable of being propelled by radiation. If we set off nuclear bombs behind the sail periodically—”
A few titters. Camille laughed the loudest. “My dear, you have sketched for us a scene out of a cartoon. Your spaceship is filled with a pile of nuclear bombs, and there’s a giant sail. On the ship is a hero who bears more than a passing resemblance to Arnold Schwarzenegger. He tosses the bombs behind the ship, where they explode to push the ship forward. Oh, it’s so cool!” As the rest of the staff joined in the mirth, she continued. “You may want to review your homework from freshman year in college and tell me: one, how many nuclear bombs your ship will have to carry; and, two, with that kind of thrust-to-weight ratio, what sort of acceleration you can achieve.”
“She didn’t manage to bend the laws of physics, but she did fulfill the other aspect of the chief’s demand,” another consulting expert said. “I’m just sorry to see such a pretty girl fall under the spell of brute force.” The wave of laughter reached a crescendo.
“The bombs will not be on the ship,” Cheng Xin replied calmly. The laughter ceased abruptly; it was as if she had put her hand on the surface of a struck cymbal. “The probe itself will be a tiny core equipped with sensors attached to a large sail, but the total mass will be light as a feather. It will be easy to propel it with the radiation from extravehicular nuclear detonations.”
The conference room became ver
y quiet. Everyone was trying to think where the bombs would be. While the others were mocking Cheng Xin, Wade’s mien had remained chilly and unmoved. But now, that smile, like water seeping from a crack in the ice, gradually reappeared on his face.
Cheng Xin retrieved a stack of paper cups from the drinking water dispenser behind her and laid them out on the conference table in a line. “We can use traditional chemical rockets to launch the nuclear bombs in advance, and distribute them along the first segment of the probe’s route.” She took a pencil and moved its tip along the line, from one cup to the next. “As the probe passes each bomb, we detonate it right behind the sail, accelerating it faster and faster.”
The men now moved their gazes away from Cheng Xin’s body. They were finally willing to take her proposal seriously. Only Camille continued to stare at her, as though at a stranger.
“We can call this technique ‘en-route propulsion.’ This initial segment is the acceleration leg, and it takes up only a tiny fraction of the overall course. As a very rough estimate, if we use one thousand nuclear bombs, they can be distributed along a path of about five astronomical units stretching from the Earth to Jupiter’s orbit. Or we could even compress it further and distribute the bombs within Mars’s orbit. That’s definitely achievable with our current technology.”
The silence was broken by a few whispers. Gradually, the voices grew louder and more excited, like a drizzle turning into a rainstorm.
“You didn’t just come up with this idea, did you?” asked Wade. He had been listening to the discussion intently.
Cheng Xin smiled at him. “It’s based on an old idea in aerospace circles. Stanislaw Ulam first proposed something like it back in 1946. It’s called nuclear pulse propulsion.”
“Dr. Cheng,” Camille said, “we all know about nuclear pulse propulsion. But those previous proposals all required the fuel to be carried aboard the ship. The idea of distributing the fuel along the spacecraft’s route is indeed your invention. At least, I’ve never heard the suggestion before.”
