Saturn Run (13 page)

Becca responded, and when she ran out of breath, Vintner asked
cheerfully, “All done? ’Cause, you know, you were repeating yourself there at the end. I think you said ‘bitch’ at least four times and ‘motherfucker’ five or six.”

“Funny. What in the hell is she doing?” Becca asked. She could feel the heat in her face: she must be glowing red on Vintner’s screen.

Vintner filled her in on the Chinese mission status and the planning session on the night before. “So that’s the size of it. I’m sending you Howardson’s new trajectory model right now.”

Becca blinked up the plots and the time markers, read through them. “Okay, that’s clever. Cutting it a little close to the sun, aren’t we?”

“Yeah, the ship design guys’ll have to rig up a heat shield for the close approach, so we don’t overload our cooling systems. Shouldn’t be a big deal. We’ll deploy an aluminized plastic film parasol that will reflect ninety percent of the extra sunlight. We’ll jettison the parasol on the way outbound. And speaking of heat, how will this impact your cooling system?”

Becca hummed for a minute. “Well, absent any clever tricks, it’ll diminish my thermal outflux by, I’m guessing, maybe twenty-five percent for about two weeks. Only while we’re within about a quarter AU of the sun. We’ll have to cut back on thrust, but that shouldn’t cost us more than a couple of days and we’re picking up, what, four months, after we add back in the extra flight time? Couple days one way or another won’t make a difference.”

Vintner nodded. “I’ll leave it to you to coordinate with the propulsion engineers and get a modified thrust profile to Howardson to plug into his model.”

“Jacob, do we need all five months? I mean, do we really have to launch at the beginning of the launch window?”

Vintner sighed. “Honestly, I don’t know. Probably not. But this is turning into more of a race than we had planned, and we don’t know what we’re going to find out there or how long we’re going to have to stick around investigating it before heading back to Earth. We don’t want to collide with the Chinese—that’s a party Santeros wants to avoid.”

“Okay.”

“Which leaves the big question. Can you complete your part of the project in nine months?”

Becca asked, “What happens if I say no?”

“Santeros doesn’t like to be told no. If I have to tell her you’re not up to it, she’ll send me off hunting for a replacement,” Vintner said. “If I hunt long enough, eventually I’ll come across someone who’ll say yes, just for the opportunity.”

Becca sighed. “No doubt. But they won’t be able to do it. There’s not enough time for them to come up to speed on my design and not enough time for them to come up with one of their own.”

Vintner nodded. “That’s pretty much my take on it. Even if you don’t think you can do it, the odds are still better if you do it than if someone else tries. So, what the hell. Say yes.”

Becca fidgeted. Buying into a schedule she didn’t believe in was a plausible path to professional suicide. On the other hand, quitting in midstream would also trash her reputation.
Game theory,
she thought.
If I quit now, I keep my professional integrity and it’s a sure loss. If I stick it out, there’s a chance I might be able to pull it off and no one will know that I was blowing smoke. A guaranteed loss vs. a possible win.

“I’ll give it a try.”

“Thanks. I’d love to be able to tell you that nobody will hold it against you if you can’t pull it off, but we both know that’d be a lie. If we don’t beat China to Saturn, we’ll all be pilloried. The President will tank and she’ll make sure we’re all in the handbasket with her. Talk to you later.”

Vintner hung up.

Becca threw her coffee cup across the room where, unsatisfactorily, it bounced without shattering off a whiteboard and landed in a corner of the carpeted floor. Fuck it, she was done for the night. She shut down her workslate, pushed back her chair, and walked out of the office. Tomorrow was going to begin an unrelenting hell. Tonight she was going to study some
margaritas.

Sandy had spent a week working on the vid for the first test of the
Nixon
’s power plant. In fact, he’d worked right through New Year’s Eve, three days earlier. Fiorella, as it turned out, was a genius at explaining complicated technical matters in terms that anyone could understand, and occasionally even laugh at.

As with Becca Johansson’s solution for dissipating waste heat from the reactors . . .

Sandy launched his egg from the central axle and took it a kilometer out. In the past year, the metamorphosis of USSS3 station into the
Richard M. Nixon
had come a long way. He’d documented all of the major construction activities, the vid instantly relayed groundside. If anything went wrong, if there were any problems, analysis of the vid might give clues for possible fixes.

The
Nixon
was obviously a reworked USSS3. It still had three parallel tubes, side by side and spaced a hundred meters apart. The two outer tubes, each a hundred meters long, still contained the ship’s living quarters and were still known as Habitats 1 and 2. The center tube, the axle, contained storage and the shuttle bay.

The axle, instead of stopping where it intersected the rear connecting elevator tubes, continued back for another two hundred and seventy meters. About halfway back on the extended axle—all of it still zero-gee—were the engineering section and the twin reactors of the nuclear power plant. At the aft end, another hundred meters away from the reactors, the VASIMRs were still under construction. Between the reactors and the engineering system were a cluster of spherical tanks that would hold the thousands of tons of water that would make up the reaction mass for the VASIMRs.

And then there was Becca’s answer to the waste heat problem. In the nine weeks since the Chinese had launched, she’d moved heaven, Earth,
and no small number of recalcitrant engineers. Between Engineering and the reactor modules, two four-hundred-meter-long masts projected out from the center axle, from Sandy’s viewpoint, one “up,” one “down.” At the end of each mast was what Sandy, who had done some sailing, thought of as a spar—but which also looked like the crossbar on a capital letter T.

Two more beams, the same length as the top spars on the T, projected out “horizontally” for a hundred meters on both sides of the axle. They held the extrusion nozzles for the molten radiator alloy that Becca Johansson would use to cool the reactors. The “T” spars would re-collect the now-frozen alloy, effectively thin sheets of foil, and send it back to the reactor.

Dozens of nearly invisible guy wires ran from the booms and masts to the axle. The guy wires were made of graphene composites that tied all the pieces into a rigid structure, far more inflexible and lightweight than any equivalent scaffold of metal. It reminded Sandy of an unfinished box kite, all balsa wood struts and string. At this moment, the struts were bare.

Shortly, there would be sails.

The engineers and design teams had fallen in line behind Becca Johansson’s scheme for handling the
Nixon
’s prodigious power demands. Not because they were happy with it; they just couldn’t think of anything else that would let them beat the Chinese to Saturn.

Grumbling, they designed a ceramic core reactor that ran at a glowing-yellow temperature and heated the primary coolant—pressurized liquid sodium—to over nineteen hundred degrees Celsius. The superheated liquid sodium ran through a heat exchanger where it boiled more sodium. That vapor drove the primary ceramic composite turbines at two hundred atmospheres and nineteen hundred degrees Celsius.

The sodium vapor condensed downstream of the turbine, in a secondary heat exchanger, where it heated steam to a supercritical eight hundred and eighty degrees. That drove the next set of turbines. Extreme as all of this was, it didn’t justify an epithet like harebrained.

The final stage was another matter.

Downstream of the secondary turbines, the steam, cooled to six hundred and fifty degrees Celsius, entered the heat exchanger for the ship’s radiators. It melted radiator alloy, a eutectic blend of aluminum, magnesium, and beryllium that liquefied at six hundred degrees Celsius. In doing so, it absorbed nearly two hundred watt-hours of heat per kilogram of melt. All Becca had to do was get rid of the heat in the molten alloy, and that was what merited the epithet.

Her heat exchanger extruded the alloy into space in molten ribbons a meter wide and a tenth of a millimeter thick. Cold rollers in the extrusion nozzles clad the ribbons in a skin of frozen and roughened alloy, just microns thick.

The rough skin improved the ribbons’ heat radiation properties and kept the thin, wide bands of liquid alloy from breaking apart into a spray of droplets. As they sped toward the spars four hundred meters away, the ribbons cooled and froze, radiating tremendous amounts of energy into space.

It was a brutally efficient scheme for dumping the vast amounts of heat, but it was tricky.

The nearly liquid ribbons of metal had to be guided electromagnetically as they squirted out from both sides of an extrusion boom, and then led to the spars over four hundred meters out. There, the solidified ribbon was fed by rollers mounted on the spars to the central masts and back down into the melting pot. Managing one ribbon was a technically challenging feat. For Becca’s system to get the
Nixon
to Saturn, it had to extrude and control hundreds of them, all at the same time.

Thus, sails—or, for the more poetic, a moth with huge wings and a tiny body.

Each of the sails comprised almost a hundred ribbons, running side by side from the boom that extruded them to the spars, across the spars and back to the heat exchanger reservoir. The alloy circulated perpetually, hundreds of semi-molten ribbons in constant motion, safely disposing of the reactors’ waste heat. When the ship was under full power, 150,000 square meters of the dull silvery metal—the equivalent of twenty-eight
American football fields—would radiate nine gigawatts of heat into space. So said the theory.

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.