“I thought the Nighthawk was destroyed on impact,” Kyra said.
Jonathan shook his head. “There was more than enough intact for an intel service to reverse-engineer. Imagery shows that the plane wasn’t vaporized.”
“Why not?” Mitchell asked, curious. “Most planes that fall from a few miles up just leave a smoking crater.”
“Nobody knows for sure,” Jonathan said. “My guess is that the fly-by-wire computers kept trying to level the plane after the pilot bailed out. Nighthawks have the aerodynamic properties of a brick. The only way one stays up is if the computers can make adjustments to the control surfaces fast enough, so the pilot uses the stick to tell the computers where he wants to go, and they figure out how to adjust the airframe to make it happen. I think the SAMs exploded close enough for the shrapnel to shred the airframe and damage the control surfaces. The pilot bailed out, but the computers kept trying to fly. They leveled the plane out enough to keep it from turning into a fireball when it hit.”
“That actually makes sense. You would think that the engineers could have come up with something that could glide in a pinch,” Mitchell mused.
Kyra stared at the iPad screen. “I read about this. Computers in the seventies weren’t powerful enough to calculate the radar cross sections of curved surfaces,” Kyra said. “They could only crunch numbers for flat surfaces, but flat areas are perfect radar wave reflectors. Right angles are the real killers because they reflect virtually the entire radar wave back to the receiver. So Lockheed had to build a plane with flat surfaces and no right angles. Now you could do the math on one of these.” She held the tablet computer up.
“The Air Force didn’t bomb the crash site?” Mitchell asked.
“Serb civilians overran the site too quickly,” Jonathan replied. “We’ve got pictures of little old Serb ladies dancing on wing sections still smoking from the impact. The idiots probably all died of cancer. And the Serbs don’t have the industry to build fighters, stealth or not, so they likely went looking to sell the technology for money. The Chinese would be the perfect buyers. They’ve got money, our technology in the Gulf War freaked them out, and they were trying to modernize their military. The Assassin’s Mace project was under way, and stealth bombers would be the perfect weapons to use against an aircraft carrier.”
“You think they’ve got a working stealth bomber?” Mitchell was engrossed now.
“Yes,” Kyra said. “Yes, they do.” She pulled the phone out of Jonathan’s hand.
The STU-III’s tiny display finally read “TS//SCI” and the secure voice button went red. Weaver had hoped that there were enough fiber optic lines between Beijing and Langley that the encrypted phones could make a connection quickly, but the wait had been painful. In truth, it probably had taken less than fifteen seconds.
The encryption stripped Stryker’s voice of life, as expected. “I hope you’ve got something for me, Mr. Weaver,” she said.
“Lunch, I think,” Weaver said. “I finished reverse-engineering the CAD app’s subroutine yesterday. I extracted the algorithm and converted it to standard mathematical notation. That took most of the night, but it’s oh so pretty. The problem is that I can’t match the equations to anything. I’m not good enough at math to know what I’m looking at,” Weaver said. He had earned a C grade in the required course for his computer science degree, and that had been a gift from a merciful professor. Weaver had never seen the point. He’d been a programmer for more than a decade now and had never needed any math beyond what he had learned in high school.
“I might be able to save you the trouble,” Kyra said.
“I’ll buy you a beer if you can.”
“You’ll be buying me more than that. Take a copy of the equations and run over to—” There was a pause as Kyra asked someone a question that Weaver couldn’t make out. The encryption stripped too much detail for him to understand quieter voices. “Run over to WINPAC.”—the Weapons, Intelligence, Nonproliferation, and Arm Control center—“You need to find a senior analyst who works air defense issues. If you can, they should be able to lay hands on a copy of a Russian science paper that will explain the algorithms.”
“It’s not on the web?”
“Only in Russian,” she explained. “You read Russian?”
“You have the title and author?”
“Theory of Edge Diffraction of Electromagnetics. Written by Pyotr Ufimtsev, 1966. The original Russian title is Metod kraevykh voln v fizicheskoi teorii difraktsii.” It sounded like Stryker was reading the titles off something. Weaver’s ear for accents wasn’t well trained, but he’d been sent to Russia on several occasions. Stryker’s Russian pronunciation sounded flawless, the accent nearly pure Muscovite as far as he could discern.
“Give me a second, I don’t have a Cyrillic keyboard,” Weaver said. He winced and hoped that Kyra appreciated sarcasm, but she sounded too tired to care. The tech stole an engineer’s graph pad from the next cubicle and hunted for a pencil. “Repeat the name.” Kyra repeated the Russian words again. “What’s the paper about?”
“Stealth.”
“I thought Lockheed Martin invented stealth in the seventies,” Weaver said.
“Ufimtsev worked out the math, but the Russians didn’t realize what it could be used for. Lockheed Martin did. We think the algorithms you extracted are Ufimtsev’s equations for calculating radar cross sections. He figured out that the size of the object reflecting the radar wave is irrelevant: all that matters is the shape. That’s why that number on the CAD program only changed when you loaded a new shape. It was the radar cross section. The actual dimensions of the object were irrelevant.”
“That’s counterintuitive,” Weaver said.
“The technology works.”
“I guess,” Weaver said. “If nobody in WINPAC has a copy of that paper, I’ll have to see if the librarians can track it down.”
“Whatever you have to do,” Kyra conceded. She disconnected the phone.
The CIA director’s secure phone rang. She enabled the encrypted connection. “Cooke.”
“It’s Burke. We’re in Seoul.”
“How were the potstickers?”
“Wish we’d had the chance to try some,” Jonathan said. “I need a favor.”
“Sure.”
“This might be nothing, but I want to rule it out if there’s no connection. Did the Taiwanese ever figure out what that chemical was that took down those SWAT officers in Taipei?”
“The Ops Center finally dropped that one on my desk yesterday, after you two started playing games with the Chinese,” Cooke said. “The chemical was something called chlorofluorosulfonic acid. Finding out what that is took another call. The common use is to inhibit water vapor from condensing at near-freezing temperatures. It’s used occasionally by DoD to break up contrails on aircraft so they can’t be tracked visually from the ground. Is that helpful?”
“You have no idea.”
“You going to tell me what this is about?” Cooke asked.
Jonathan told her. “Kyra and I need a flight to one of the carrier battle groups in the Strait,” Jonathan said.
“Not a chance. I am not sending you two into an active war zone,” Cooke declared.
“We know what the Assassin’s Mace is. I can either explain it to an admiral in person, or I can explain it in a cable and we can pray that he bothers to read it and loves my Shakespearean prose.”
“You’re not the most charming analyst.”
“Charming enough for you, I hope,” Jon answered.