As for the practice, the first full-scale test would give them a good idea of what worked, and what might not.

The power engineers had to bring the reactors online to produce enough heat and power to test out the turbines and the boilers and melt the alloy reservoir of the heat exchanger. But they couldn't go too far, too quickly, because the relatively puny auxiliary cooling system had to handle the thermal load until the main heat exchanger was fully operational. It was a delicate matter. Reactors of this design didn't really like being run at less than one percent of their rated output. If an instability got out of hand it could result in a core meltdown, and that would be the end of the mission, and possibly the space station.

From a cinematographer's point of view, the first days were mind-blowingly boring. When you've photographed one status display being monitored by a furrow-browed engineer, you've photographed them all.

But after a week, life got interesting again. The reactors were as happy as they were ever going to be; the heat exchanger reservoir was stable at its operating temperature of just over six hundred degrees Celsius; and all the guidance sensors were nominal. Becca had taken a deep breath and given the instruction to open one slot nozzle, at minimum operating pressure.

Slowly, slowly a tenth-millimeter-thick, meter-wide ribbon of metal crawled out of the boom toward one of the spars. It wavered for a moment, wobbled, and then the guidance sensors and control magnets latched onto it. Dedicated supercomputers analyzed the ribbon's hesitant path and issued instructions to guidance magnets to induce precisely formulated eddy currents into the ribbon. Electromagnetism did its part; the ribbon was forced back onto the straight and narrow toward the waiting spar.

After two minutes, the leading end of the ribbon reached the recovery spar, was picked up by the rollers, and fed across the spar and back down the mast.

Engineering broke out in cheers. Sandy was happy; it was dramatic. That languorous silver band creeping across four hundred meters of space was great for building tension, and Sandy planned to include every second of that footage in the final cut. Make the audience sweat the same way the engineers had.

The engineers opened the second nozzle and extruded a second meter-wide ribbon. It behaved much like the first. There were three hundred and fifty more of these to go. Allowing for pauses for status checks, the engineers would be at it for eighteen hours before all four sails were fully deployed. Sandy stuck a camera on a station-keeping pod to record the repetitive affair in real-time mode, and left for the day.

Back in the ship, he headed into a ladies' restroom, where he found Martinez gluing a toilet-paper holder in one of the booths, while Fiorella, standing outside, was getting her hair done. She said, "You're late."

"But not too late," Sandy said. "I was here earlier, I worked out the lighting."

The Reds he was using didn't need much light, but Sandy needed shadows-the light in the restroom was simply too flat and indirect to be interesting. He rolled his equipment case into the restroom and began sticking LED-light panels to the walls.

When they were ready, Fiorella sat on the toilet seat. On either side of her, at chest height, were two toilet paper rollers, one with a roll of toilet paper on it, the other bare; Martinez had installed the second one, and moved the first one to the right height for the shot.

They were about to start shooting when Fang-Castro stuck her head in the door and said, "I really didn't want to know about things like this, but then somebody had to tell me. Why did they do that? Why do people tell me about things like this?"

She shook her head and disappeared again.

"Heckled from the cheap seats," Martinez said.

Sandy had stuck his Reds to the restroom walls, controlling them from his slate, and said, "We're on."

Fiorella said to the cameras, "The problem was getting rid of the heat. The only feasible way to do that was to extrude extremely thin bands of molten metal into space, where, after they froze-thus getting rid of all the heat-they'd be gathered up and recycled into the ship's reactor, where they'd be remelted. . . .

"Think of it as working like this toilet paper roll." She took a tab of toilet paper between her fingers and began pulling it across in front of her, toward the bare roller. "The molten metal is extruded into space, in a ribbon, like this paper. It then crosses to the other side, where it is picked up by a roller."

Martinez had put a thin line of adhesive on the top of the roller, and Fiorella carefully stuck the paper to it, then began turning the empty roller, taking up the toilet paper.

They did it seven times before they had enough fragments of good vid that the editors could make it into one continuous segment; and it ended with Martinez on his back, under the toilet and between Fiorella's legs, providing invisible drag on the feed roller with his fingers, while Sandy focused on bringing up the gold flecks in Fiorella's eyes.

When they were done, and Fiorella and Martinez were back on their feet, Martinez said, "That was really pretty easy, except when the toilet paper broke."

"That's why we have editors," Sandy said. "The paper won't break on screen."

The next morning, back in his egg, Sandy watched as four giant frosted-pewter rectangles of metal, hundreds of meters in size, ran from the spars to the booms, like square-rigged sails. The alignment was so perfect that from a distance the sails looked like single sheets instead of hundreds of parallel ribbons of radiator alloy.

He recovered his automated camera and moved it, reset it, changed memory modules: the cameras had both internal memory and simultaneous remote recording capability that went straight into a dedicated memory core in the station. Some videographers thought the equipment was now so good that no backup was really needed. Sandy had never believed that: he backed up everything.

He was outside that morning because Becca Johansson and the other engineers were finding out if their baby could walk. The reactor managers would take their plants up to twenty-five percent of rated output, the first field test of the reactors under anything close to normal operating conditions. For the time being, they'd be bypassing the turbine-generator stage. Dumping all the power into the heat exchanger would test its capabilities to over fifty percent of full capacity.

Ramping up the heat exchanger-radiator system was simple enough in concept; it just required speeding up the extruders. The faster the metal got fed into space, the faster they could dump waste heat. Currently the extruders were streaming ribbons at a leisurely three meters per second, but in full operation the ribbon velocity would be over a hundred and sixty meters per second. The plan for the day would be to take the ribbons to ninety meters per second. If that worked, the system would be taken down while Sandy and the other engineers went over every bit of data produced by the dozens of recorders watching the event.

Even at the slower ninety meters per second, everything needed to work hand in hand perfectly. The heat exchanger needed sufficient heat coming in from the reactors to keep the alloy reservoir molten. If the extruders ran too fast for the reactors, the exchanger would dump too much heat into space and the reservoir would cool down. If the temperature dropped below the six-hundred-degree melting point of the radiator alloy, the reservoir would freeze up and the engineers would have to shut it down. So the reactors depended upon the heat exchanger to keep from melting down, and the heat exchanger depended upon the reactors to keep from freezing up.

Sandy, waiting for the test to begin, focused on giving Fiorella as many different views of the station as he could, using a variety of imaging techniques. He would switch from normal real-color imaging to thermal imaging, and the sails would go to a brilliant white, set in a framework of dim, dark gray masts and booms and other station components, with a dull gray Earth in the background. When he had enough of that, he thumbed through a variety of alternative modes, doing false-color mapping, which showed sail temperatures in a rainbow of hues. Fodder for the editing session later; anything to jazz up the presentation.

When the test began, it looked like nothing. Nothing changed.

Sandy slowly panned back and forth over the station, muttering notes to himself into his throat mike, the Red dutifully capturing all that as well as multiple channels of audio from Engineering.

In fifteen minutes, he had more vid than Fiorella would ever be able to use, so he picked the best spot, a kilometer out, set two cameras at different focal lengths, picked up his slate, and went back to a novel he'd been reading.

In an hour, the reactors were up to five percent, dumping nearly a gigawatt of heat into the exchanger and radiators. Ribbons streamed out at twenty meters a second. The reactor managers sounded happy. The heat exchanger engineers sounded happy. Dr. Johansson sounded slightly less stressed than usual. Sandy went back to his novel, a bit of undemanding popular science-fictional fluff about the first space mission to Jupiter. Set ten years in the future, he thought. How quaint: this mission would blow Jupiter's doors off.

Each time he scrolled the tab's screen, Sandy glanced up at the sails. The Reds would run fine on their own, unattended, he was just spot-checking. As the station moved in its orbit about the earth, the sun's light constantly changed angles and intensity. There was the especially dramatic transition from lightside to darkside and vice versa on the earth. Sure, it was repeated every two hours, but audiences lapped it up. More eye candy he could edit into the footage so that viewers wouldn't notice that nothing interesting was happening. Occasionally he panned across the earth to capture the sunset/sunrise terminator and its delicate rainbow, or the lights from humanity's bigger and brighter megaplexes.

Two and a half hours into the test, Fiorella and Martinez came out in separate eggs, Fiorella's egg slaved to Martinez's. Sandy spent an hour doing close-up shots of Fiorella in her egg, commenting on the sails in the background. Martinez hovered behind Sandy, out of camera range.

When they were satisfied with the vid, Martinez and Fiorella looped over to the far side of the test ribbons, so that Sandy could shoot them with the ribbons in the foreground, the earth in the background.

The reactors were up to twenty percent. The heat exchanger was happily dissipating 3.5 gigawatts, its ribbons zipping along at seventy meters per second. Out of the corner of his eye, Sandy caught a glimmer of light off one of the sails. Something different.

He said, "I'm seeing something different out there, what's . . . Hey! You guys! Joe! Cassie! Back up! Back up! Get out of there, get away!"

He started to zoom in on that section of that sail with Camera 1, his longest lens, when he saw more glimmers, then ripples of light starting to flicker across the sail. He zoomed Camera 2, catching the ripples, but carefully kept Fiorella's and Martinez's eggs in the shot, then thumbed over to object-lock, locking Fiorella's egg onto Camera 2. It would track her wherever she went, within the limitations of his egg's attitude and the Red's gimbals. Martinez was backing them off, as the ripples and flickers extended over all four sails.

A second later, the sails exploded.

That's what it looked like, anyway, from Sandy's vantage point.

The three hundred and fifty-two silvery metal ribbons making up the sails broke free of their lock-step, straight-as-arrow paths and went flying wildly into space, thin silver streamers spewing out in all directions like Christmas tinsel.

He'd dealt with any number of explosions in the Tri-Border area, and one of the things that he had learned was that if the explosion didn't kill you outright, you could get killed by the stuff coming down. Like bricks. He'd trained himself to look up after something blew: a flying brick was like a softball lofted into the outfield, and you could easily dodge it, if you could see it. Your mind would automatically scope out the vectors of the various flying pieces of rubble.

As the cloud of silvery threads grew, Sandy saw a hole forming in the expanding ball of chaff, and his explosion-trained brain told him the various object vectors wouldn't be passing through the hole. He jammed the egg into it, careful to keep the egg oriented toward Fiorella's and Martinez's eggs, so Camera 2 could track them. He put Camera 1, with the half-million-dollar lens, on the corner of the extruder where the ripples had started and thumbed the constant focus setting, and closed in on it, at the same time selecting both real-color and thermal settings, and the highest recording speed.

As he dove in on the extruders, Martinez started screaming at him: "Get out of there, you crazy motherfucker. Go north, go north. Get out . . ."

Fang-Castro's cool voice interrupted: "Mr. Darlington, do what you think best. Those vids will be valuable. Mr. Martinez, try not to distract Mr. Darlington any more than is necessary to warn him of a problem he may not be able to see."

Then another woman's voice, as cool as Fang-Castro's: "This is Johansson. Darlington, we're monitoring your vid. We could use a full scan of the extruder bar at your best resolution in both real color and thermal-"

"Doing that, real color and thermal, I'll need to close a bit more to get the best resolution."

Although he was focused on the technical video going into Camera 1, he made sure that Camera 2 stayed locked on Fiorella. He was shooting her through the expanding ball of silvery chaff, and though he knew at the back of his mind that the chaff represented a disaster, it was also one of the most beautiful things he'd ever seen, the metallic strands writhing in the sunlight, with the blue-marbled Earth far below: and Fiorella's egg right in the center of the shot.

As an honorary techie, he was appalled. Something had gone badly wrong. The test was clearly a failure. Was it a fatal one, in terms of either the mission or the people? He switched his headset over to the engineering channels the Red had been recording and caught the stream of reports coming into the chief reactor manager and Becca Johansson and quickly caught up on the status.

No permanent damage done to the station or to the mission, no human injuries of any kind, though Johansson sounded mightily pissed off. From what he could tell, the ribbon guidance system had cratered. As the speed of the ribbons increased, an instability appeared. From what he could hear over the audio links, the engineers didn't know if it was vibration in the extruders or some sort of feedback loop between the ribbons and the sensors and the control magnets, or if the computer controls hadn't been up to the task.

Whatever, those fast-flying ribbons had developed wobbles and the wobbles had grown uncontrollably until finally the whole control system collapsed under impossible demands and the ribbons started flying off in all directions.

He'd reached the end of the extruder bar and he clicked over to the engineering channel and asked, "You need another run on the extruder bar?"

Johansson came back almost immediately.

"If you can, give me a thermal image of the end of the bar where the instability started. Just leave it there for a while. Two minutes, anyway."

"Doing that now," Sandy said.

Fiorella called, "I don't want to seem crass," she began.

"Never bothered you in the past," Sandy said.

"I'm laughing inside," she said. "Tell me that you got at least a few seconds of our eggs floating in the background, when the thing blew."

"Camera two was locked on you the whole way, and still is. The chaff is clearing out. If you want to motor over this way, we could do a tracking shot of you coming in, right up to your face. Dodge around a few pieces of the metal-that should look pretty spectacular."

Fiorella asked, "Joe, can we do that?"

"Yeah, we can do it, but I still say he's a crazy motherfucker."

Crazy motherfucker I might be, Sandy thought, and it was all chaos theory in motion and one hell of a screwup: but, ohmigawd, that's entertainment!

Becca ran all night on coffee, junk food, and stims. If the spectacular radiator failure, recorded for all posterity by that goddamn videographer, turned out to be an unsolvable fatal flaw in her engineering . . . guess who'd be America's chosen dumbass for the next hundred years?

The vid of the heat exchange extruder bar had given them some clues to the problems, but not the details. The vid had been valuable-but she hadn't been aware that the videographer had also been doing news vid, even as he was recording the technical stuff.

All Becca had to do was close her eyes, and she'd see that gorgeous redheaded creature on the screen, gold flecks in her eyes, as she sat in her egg, unnaturally calm. "We've had a disaster here. The first trial of the critical heat exchangers in America's Saturn ship . . ."

And the vid flew backwards in time to show the ribbons of superheated metal exploding into space. It was, Becca had been told, the single most-watched vid of the current century except for those of the 9/11 Twin Towers attacks and the Houston Flash.

The logs on her work screens wandered in and out of focus. She rubbed her eyes; no sleep for the wicked. She'd eliminated the control sensors and magnets as the source of the problem. The data said they were up to the task, they just hadn't been provided proper control. The problem still might turn out to be an oscillation in the ejection nozzles for the heat exchanger, but she was betting on the supercomputer array.

At high ribbon run speeds, it was probably getting swamped with data and the granularity of the modeling just wasn't fine enough to deal with it. Which meant more supercomputers-easy enough to come by with an unlimited budget-and better, finer-grained control code. None of it would come with a snap of her fingers, but later today, she'd meet with the code monkeys and rake them over the coals.

She pulled up the logs for the nozzles. Even if it turned out that they weren't misbehaving, the cleaner they operated the easier it would be for the supercomputers to control the ribbons. She'd started looking for a signal in the noise, when she got beeped for a priority call that overrode her privacy block.

"Yeah, who? I'm busy and I'm not happy, so don't be wasting my time."

"Dr. Johansson, President Santeros here. I'm even less happy than you are. Yesterday's fiasco looked bad. You need to-"

Becca cut her off. "That was not a fiasco. It was an experiment, a test. The first one on an untried system. The system failed. The data will tell me why it failed."

"Dr. Johansson, don't interrupt me again! Not unless you want to be looking for a new job."

Becca had heard about Santeros's temper; this was a small sample of it. But, ever since she'd been the fat little blond kid, she'd hated being pushed around. Now that she was a fat little blond adult, she didn't like it much better. It got her Midwest backbone up. She knew the smart thing would be to smile, apologize, and kowtow.

"Good luck with that," she snapped. "You want to find a replacement for me, you're welcome to try. At this late date, it's only gonna push your launch back by a year."

Santeros was turning red.

"One more thing," Becca said. "You're not my boss. You want me fired, call my boss. Right now, YOU are wasting MY time. Stop trying to bully me and let me do my job."

She hung up. Not my best career move. I should probably start packing my stuff. Or keep working on these logs until they come and kick me out. Eh, screw it. I need a break.

Becca kicked out of her chair and headed to the commissary. Reflexively she tried to shove the door behind her as she left, but it just slid closed with a soft hydraulic snick. Can't even slam a goddamned door in this place, she fumed.

A thousand kilometers down, Santeros looked at her science adviser. "That little bitch just hung up on me! She's history, Jacob. Get a replacement on board and get rid of her."

Vintner glanced over at Crow, who raised one thin, dark eyebrow. Otherwise his face remained a carefully composed blank. Vintner suppressed a smile. "Madam President, I say this with all due respect . . . Uh, no."

"That wasn't a request, Jacob."

"Planning to fire me, too? I'm your adviser-let me advise. First, she's right. The only thing replacing her will do is to set us back by more time than we can afford. You replace her, the Chinese get to Saturn first."

"Meaning I'm supposed to put up with that?"

"Yes. That's what I mean. You were elected President, not the Red Queen. You chop off her head, you'll be cutting off your own at the same time. Let it go."

Santeros looked like steam might start flowing off her forehead, but then she slowly cooled off, and finally smiled. "All right."

Crow raised a finger.

Santeros asked, "What?"

Crow said, "I don't think we should rule out sabotage as an explanation."

"Do you have any evidence to support that, Mr. Crow?"

He shook his head. "Nothing. Barely even a feeling. But there are so many holes a saboteur could slip something through, so many moving parts. And God help us, how many times have we proven in the past that it's impossible to vet everyone perfectly? Plus, everything-the hardware, the software, even the procedures and protocols, are prototypes that are getting tested and debugged in the field. So many places for things to go wrong, for an unwanted modification to be snuck in."

Santeros said, "Jesus. This radiator thing hurts. This really hurts. I don't see what we can do here."

"I don't know that I'll ever have more than a hunch, but in the meantime I'd be a lot happier, from a security point of view, keeping the devils I know," Crow said. "Minimize personnel changes. Like Johansson."

- After talking with Santeros, Becca was bouncing off the walls.

Literally.

In 0.1 gee, it wasn't hard to go careening about unless she paid a lot of attention to controlling her actions, and right now she wasn't feeling much like controlling anything. She was pissed. She wasn't really hitting the walls hard enough to hurt, but it felt good to be slamming something. The corridor was empty of other crew members, so all that got bludgeoned were the walls.

She lurched into the commissary and ran full tilt into a large male figure. They both bounced back in low-gee arcs, as their sticky boots lost their grips on the floor, like two cartoon characters. A lidded zero-gee coffee mug traversed its own lazy trajectory across the room.

"Oh, God, I'm sorry . . ." the guy said.

"Damnit, look where you're . . ." She landed, regained her footing, and looked at the human obstacle she'd just bounced off of. It was the Hollywood pretty-boy videographer guy. Oh, lovely.

"Uh . . . Are you okay?" Sandy asked her. "You don't look okay."