Wednesday 2:25 A.M.

_

_Yuri Andreevich Androv stood facing the bulkhead that sealed the forward avionics bays, feeling almost as though he were looking at a bank vault. As in all high-security facilities, the access doors were controlled electronically.

Since the final retrofits were now completed, the Japanese maintenance crews were only working two shifts; nobody was around at this hour except the security guards. He'd told them he'd thought of something and wanted to go up and take a look at the heavy-duty EN-15 turbo pumps, which transferred hydrogen to the scramjets after it was converted from liquid to gaseous phase for combustion. He'd been worrying about their pulse rating and couldn't sleep.

He'd gone on to explain that although static testing had shown they would achieve operating pressure in twenty milliseconds if they were fully primed in advance, that was static testing, not flight testing, and he'd been unable to sleep wondering about the adhesive around the seals.

It was just technical mumbo-jumbo, although maybe he should be checking them, he thought grimly. But he trusted the engineering team. He had to. Besides, the pumps had been developed specially for the massive Energia booster, and they'd functioned flawlessly in routine launchings of those vehicles at the Baikonur Cosmodrome.

Of course, at Baikonur they always were initiated while the Energia was on the launch pad, at full atmospheric pressure. On the _Daedalus_ they'd have to be powered in during flight, at sixty thousand feet and 2,700 miles per hour. But still . . .

The late-night security team had listened sympathetically. They had no objection if Androv wanted to roll a stair-truck under the fuselage of _Daedalus /, _then climb into the underbay and inspect turbo pumps in the dead of night. Everybody knew he was eccentric. No, make that insane. You'd have to be to want to ride a rocket. They'd just waved him in. After all, the classified avionics in the forward bays were secured.

He smiled grimly to think that he'd been absolutely right. Hangar Control was getting lax about security in these waning days before the big test. It always happened after a few months of mechanics trooping in and out.

That also explained why he now had a full set of magnetic access cards for all the sealed forward bays. Just as he'd figured, the mechanics were now leaving them stuffed in the pockets of the coveralls they kept in their lockers in the changing room.

Time to get started.

There was, naturally, double security, with a massive airlock port opening onto a pressure bay, where three more secure ports sealed the avionics bays themselves. The airlock port was like an airplane door, double reinforced to withstand the near vacuum of space, and in the center was a green metallic slot for a magnetic card.

He began trying cards, slipping them into the slot. The first, the second, the third, the fourth, and then, payoff. The three green diodes above the lock handle flashed.

He quickly shoved down the grip and pushed. The door eased inward, then rotated to the side, opening onto the pressure bay.

The temperature inside was a constant 5 degrees Celsius, kept just above freezing to extend the life of the sensitive electronic gear in the next three bays. The high-voltage sodium lamps along the sides of the fuselage now switched on automatically as the door swung inward. He fleetingly thought about turning them off, then realized they weren't manually operated.

Through the clouds of his condensing breath he could see that the interior of the entry bay was a pale, military green. The color definitely seemed appropriate, given what he now knew about this vehicle.

He quickly turned and, after making sure the outer door could be reopened from the inside, closed it behind him. When it clicked secure, the sodium lights automatically shut off with a faint hum.

Just like a damned refrigerator, he thought.

But the dark was what he wanted. He withdrew a small penlight from his pocket and scanned the three bulkhead hatches leading to the forward bays. The portside bay, on the left, contained electronics for the multimode phased array radar scanner in the nose, radar processors, radar power supply, radar transmitters and receivers, Doppler processor, shrouded scanner tracking mechanism, and an RF oscillator.

He knew; he'd checked the engineering diagrams.

He also knew the starboard equipment bay, the one on the right, contained signal processors for the inertial navigation system (INS), the instrument landing system (ILS), the foreplane hydraulic actuator, the structural mode control system (SMCS), station controller, and the pilot's liquid-oxygen tanks and evaporator.

The third forward bay, located beneath the other two and down a set of steel stairs, was the one he needed to penetrate. It contained all the computer gear: flight control, navigation, and most importantly, the artificial intelligence (AI) system for pilot interface and backup.

He suddenly found himself thinking a strange thought. Since no air- breathing vehicle had ever flown hypersonic, every component in this plane was, in a sense, untested. To his mind, though, that was merely one more argument for shutting down the damned AI system's override functions before he went hypersonic. If something did go wrong, he wanted this baby on manual. He only needed the computer to alert him to potential problems. The solutions he'd have to work out with his own brain. And balls. After all, that's why he was there.

As he walked down the steel steps, he thumbed through the magnetic cards, praying he had the one needed to open the lower bay and access the computers. Then he began inserting them one by one into the green metallic slot, trying to keep his hand steady in the freezing cold.

Finally one worked. The three encoded diodes blinked, and a hydraulic arm automatically slid the port open. Next the interior lights came on, an orange high-voltage sodium glow illuminating the gray walls.

This third bay, like the two above it, was big enough to stand in. As he stepped in, he glanced back up the stairs, then quickly resealed the door. Off went the lights again, so he withdrew his penlight and turned to start searching for what he wanted.

Directly in front of him was a steel monolith with banks of toggle switches: electrical power controls, communications controls, propulsion system controls, reaction-control systems. Okay, that's the command console, which was preset for each flight and then monitored from the cockpit.

Now where's the damned on-board AI module?

He scanned the bay. The AI system was the key to his plan. He had to make certain the computer's artificial intelligence functions could be completely shut down, disengaged, when the crucial moment came. He couldn't afford for the on-board system-override to abort his planned revision in the hypersonic flight plan. His job tonight was to make sure all the surprises were his, not somebody else's. There wouldn't be any margin for screw-ups. Everything had to go like clockwork.

He edged his way on through the freezing bay, searching the banks of equipment for a clue, and then he saw what he was looking for. There, along the portside bulkhead. It was a white, rectangular console, and everything about it told him immediately it was what he wanted.

He studied it a second, trying to decide where to begin.

At that moment he also caught himself wondering fleetingly how he'd ever gotten into this crazy situation. Maybe he should have quit the Air Force years ago and gone to engineering school like his father had wanted. Right now, he had to admit, a little electrical engineering would definitely come in handy.

He took out a pocket screwdriver and began carefully removing the AI console's faceplate, a bronzed rectangle. Eight screws later, he lifted it off and settled it on the floor.

The penlight revealed a line of chips connected by neat sections of plastic-coated wires. Somewhere in this electronic ganglia there had to be a crucial node where he could attach the device he'd brought.

It had taken some doing, but he'd managed to assemble an item that should take care of his problem beautifully when the moment came. It was a radio-controlled, electrically operated blade that, when clamped onto a strand of wires, could sever them in an instant. The radio range was fifty meters, which would be adequate; the transmitter, no larger than a small tape recorder, was going to be with him in his flight suit. The instant he switched the turboramjets over to the scramjet mode, he was going to activate it and blow their fucking AI module out of the system. Permanently.

He figured he had ten minutes before one of the security team came looking to see what he was doing; he'd timed this moment to coincide with their regular tea break. Even the Japanese didn't work around the clock.

Now, holding the penlight and shivering from the cold, he began carefully checking the wires. Carefully, so very carefully. He didn't have a diagram of their computer linkages, and he had to make sure he didn't accidentally interrupt the main power source, since the one thing he didn't want to do was disconnect any of the other flight control systems. He wanted to cut in somewhere between the AI module's power supply and its central processor. The power source led in here .

. . and then up the side over to there, a high-voltage transformer . .

. and then out from . . .

There. Just after the step-up transformer and before the motherboard with the dedicated CPU and I/O. That should avoid any shorting in the main power system and keep the interruption nice and localized.

The line was almost half an inch thick, double-stranded, copper grounded with a coaxial sheath. But there was a clear section that led directly down to the CPU. That's where he'd place the blade, and hope it'd at least short- circuit the power feed even if it didn't sever the wires completely.

He tested the radio transmitter one last time, making sure it would activate the blade, then reached down and clamped the mechanism onto the wire, tightening it with thumb screws. When it was as secure as he could make it, he stood back and examined his handiwork. If somebody decided to remove the faceplate, they'd spot it in a second, but otherwise . . .

Quickly, hands trembling from the cold, he fitted the cover back on the module and began replacing the screws with the tiny screwdriver. It wasn't magnetized, a deliberate choice, so the small screws kept slipping between his bulky fingers, a problem made more acute by the numbing cold.

Three screws to go . . . then he heard the noise. Footsteps on the aluminum catwalk in the pressure bay above. . . . _Shit_.

He kept working as fast as he could, grimly holding the screws secure and fighting back the numbness and pain in his freezing fingers.

Only one more. Above, he could hear the sounds of someone checking each of the equipment bays, methodically opening and then resecuring them.

First the starboard side bay was opened and closed, then the portside bay. Now he heard footsteps advancing down the metal stairs leading to the computer bay. They were five seconds away from discovering him.

The last screw was in.

He tried to stand, and realized his knees were numb. He staggered backward, grabbing for something to steady himself . . . and the light came on.

"Yuri Andreevich, so this is where you are. What are you doing here?"

It was the gravel voice of his father. He felt like a child again, caught with his hand in his pants. What should he do? tell the truth?

"I'm--I'm checking over the consoles, passing the time. I couldn't sleep."