Thomas Hoover: Project Daedalus

"Androv, you idiot. What in hell are you doing? Defecting to the capitalists?" The voice laughed. "We don't know what the devil you're flying, but when you pulled that Immelmann, my IR thought you were an An-124 Condor transport turned into a high-performance Foxbat. One incredible son-of-a-bitch."

"It's a spaceship, Arkadi. Excuse me, Colonel Arkadi. Congratulations on the promotion."

"Spacebo," he said, laughing again. Then he sobered. "Yuri, I don't know what this is all about, but I'm instructed by General Sokolov to escort you and that thing you're flying back to Hokkaido. If you're stupid enough to refuse, then I have orders to shoot you down."

"Is that any way to treat an old friend?"

"Yuri Andreevich, we go back a long way. To the Ramenskoye Flight Test Center. You were the best we ever had. Don't make me do this."

"I'm thinking I may spare you the trouble."

"Thank God."

"Give me five minutes. If I don't turn back by then, give it your best."

"Pull up. Show yourself on IR. We have no idea what your vector is."

"I'll take her to three thousand meters. You'll have a lock on me. But I still want five minutes."

"That's all I can give you, Yuri. After that…" His voice trailed off.

"I'm going off this frequency. Talk to you in five."

"Five minutes. Starting now."

Androv pushed a switch on the console, then said, "Petra, stabilize at three thousand."

“Three thousand,” she repeated. “Confirmed.”

He rose from the pilot's seat, motioning for Vance. There was a surge of acceleration as the vehicle changed pitch, the cockpit rotating to adjust for the G-forces. The weight of two and a half G's weighed against them as the altimeter screen started scrolling upward.

Vance walked across to the central seat, studying the console. The throttle quadrant and sidestick he understood, but most of the other controls were new to him. Maybe it didn't matter.

"Does Petra understand English?"

"Of course," Androv nodded. "Russian, Japanese, and English. Interchangeable. She's programmed such that if you command her in Russian, she replies in Russian. If you use English, that's what you get back."

"So far, so good." He looked at the large screen at the end of cabin, the one that displayed Petra's mindstate. She was dutifully announcing that she'd just taken the vehicle to three thousand meters. She also was reporting the IR interrogation of a wing of MIG 31s flying at twenty thousand feet, with a closure rate of three hundred knots. When Daedalus made her move, would she be able to outdistance their air-to-air missiles?

We're about to find out, he thought, in-he glanced at the screens-three and a half minutes. Eva was zipping up her pressure suit now, readying to strap herself back into her seat. The helmet made her look like an ungainly astronaut.

"Like I said, the scramjets become operable at Mach 4.8," Androv went on. "At forty thousand feet, that's about three thousand miles per hour. I've never taken her past Mach 4.5." He was grasping the side of the console to brace himself. "You probably know that scramjets require a modification in engine geometry. In the turboramjet mode, these engines have a fan that acts as a compressor, just like a conventional jet. However, when we switch them over to scramjet geometry, the turbines are shut down and their blades set to a neutral pitch. Next the aft section of each engine is constricted to form a combustion chamber-the shock wave inside becomes the 'compressor.' " He paused. "The unknown part comes when the fans are cut out and the engine geometry is modified. I've unstarted the fans and reconfigured, but I've never fed in the hydrogen. We simply don't know what will happen. Those damned turbines could just explode."

"So we take the risk."

"There's more," he continued. "The frictional heat at hypersonic speeds. Our liquid hydrogen is supposed to act as a heat sink, to dissipate thermal buildup on the leading edges, but who the hell knows if it'll work. We're now flying at about fifteen hundred miles per hour. When you give Petra the go-ahead, we could accelerate to ten, even fifteen thousand miles per hour. God help us, we may just melt."

"If you were willing to give it a shot, then I am." Vance looked up at the screens. "We're now at ten thousand feet. I kick over to scramjets at forty thousand?"

"The computer simulations all said that if we go hypersonic below sixty thousand feet, we could seriously overheat. But maybe if we climb out fast enough…"

"We'll have to take our chances. We need to minimize that window of AAM vulnerability."

"I agree." Androv gestured for him to sit, then glanced up at the screens. "We have two and a half minutes. I've set Petra for full auto. All you have to do is just talk her through the key intervals of the sequence."

Vance settled in and examined the huge flight helmet looming above him, making him look like an alien insect from science fiction. Now the cabin had taken on an eerie quiet, with nothing but silent screens flashing data. He'd never talked to an airplane before, and the thought gave him some disquiet.

Two minutes.

"What do I do first?"

"You probably should start by attaching that nozzle there on the legs of your G-suit to the pressure hose on the console. When the G-forces go above eight, tubules in the legs automatically inflate using bleed air from the engines. It's going to squeeze hell out of your lower extremities. If you begin to gray-out, try to grunt as hard as you can. The M-l maneuver, I think you Americans call it. If your vision begins to go entirely, just try and talk Petra through."

"What else?"

"Once you start pushing through the hypersonic barrier, keep an eye on screens B-5 and B-6, which report engine strut temperature and stress loads. Those are the most important data for the scramjet mode. But first check the C-2 screen. Core rpm has to be zeroed out before the scramjet geometry modification, since the compressors need to be completely shut down. If it's not, then instruct Petra to abort the sequence. It could cause a flameout."

"And that's when I switch over to liquid hydrogen?"

"Exactly. Petra will set the new engine geometry, then sample compression and temperature and tell you the precise moment. But the actual switch-over is manual. I insisted on it." He pointed. "It's those blue toggles right behind the throttle quadrant. Just flip them forward."

"Got it."

"After you toggle her over, just ease the throttle forward, and pray." He settled himself into the right-hand seat, tugging at the tourniquet. "When we enter the hypersonic regime, I don't know what will happen. Above Mach 6 or Mach 7 we may begin to critically overheat. Or the airframe stresses could just tear this damned samolyot apart. Whatever happens, though, you've got to keep pushing her right on out, to stabilize the shock wave in the scramjets and bring them to full power."

Vance glanced up at the screen-thirty seconds-and fingered the sidestick and the throttles, trying to get their feel. As he began lowering the massive flight helmet, he noted that with the engines on military power they had exactly eighteen minutes of JP-7 left. When he kicked in the afterburners to push them into the hypersonic regime, the fuel readings would start dropping like a stone. But this was their ball of string, their way out of the maze. Would it work?

"Remember," Androv said with finality, "just talk Petra through any problems you have. And try to capture an attitude of sixty degrees alpha…"

"Yuri, are you ready for us to escort you back?" The radio voice, speaking Russian, sounded through the cabin.

"I'm still thinking it over," he answered.

"Don't be a fool. I have orders to down you with AA-9s. My weapons system is already turned on. Warheads are locked. You're as good as dead. If I push the fire button here under my left thumb, you're gone in fifty seconds."