Saturn Run by John Sandford, Ctein

washed and ironed, and the apartment was spotless. If she dropped a crumb from the always-available crumb cake, and left it on the counter, the crumb would be gone the next time she got home.
    The only thing the door, and the government, couldn’t get her was the one thing she most desperately needed: time. There was plenty of money—she’d told Vintner that she needed a better workslate, and six hours later, she got the best one that she’d ever heard of. He just couldn’tget her another three hours in the day, or an extension on the flight deadline.
    Planetary alignments defined the launch window. The shortest and fastest trip meant launching in November, only eight months away, or December of the next year. Santeros wanted to go this year, but every engineer involved had told her that was impossible. Doing it in twenty-one months would be hard enough.
    What was causing her sleepless nights, and obsession with integrals, was that she wasn’t convinced that twenty-one months was enough time. Pushed by presidential imperative, the DARPA engineers were proposing what at first glance seemed like a harebrained scheme: take the two habitat modules from U.S. Space Station Three, build it a new back end with a nuclear power plant and some heavy-duty electric-ion rockets called VASIMRs, strap on several thousand tons of water to provide oxygen and hydrogen for the VASIMRs, and off they went to Saturn.
    Except that they wanted to get this all built in less than two years and they wanted the trip to take less than five months. And that was mildly insane.
    No laws of physics were broken, it was simply an impossibly tight deadline and an unreasonably large amount of power. If they’d told her she had three years to get the ship built, and two years to get to Saturn, no sweat.
    That’s what she told them.
    In turn, they fed her details of the Chinese Mars mission, and just how good the Chinese were at large-scale orbital spaceship construction, and how long they thought they had before the Chinese might find out that something was up at Saturn, and how fast the Chinese might be able to get there once they did.
    With an ETA of a little over two years, the DARPA brains were pretty confident they could beat the Chinese. Five years? Might as well not even try.
    Rock and a hard place.
    The amount of power involved
was
unreasonable. Not impossible,just unreasonable, comparable to the amount used by the entire Twin Cities.
    The reactors themselves weren’t a problem. There were designs dating back to the twentieth century that could generate enough heat in a space not much bigger than her kitchenette. She knew how to get that heat out of the reactor with a pressurized liquid sodium cycle; that was also well-understood tech. Getting the turbines and generators down to a workable size was a bit of a do, but Vintner had people working on that and they claimed they had the matter in hand.
    But what came after the turbines?
    There are some laws of nature that can’t be ignored: thermal electric power plants generate lots of waste heat. Gigawatts of it have to go somewhere out of the system, and Becca didn’t have the luxury of building some honking big cooling towers to dissipate it. Size and weight were at a premium, and you couldn’t carry along all that cooling water to boil off. The water alone would weigh millions of tons.
    So now she was using the super-slate to run simulations for increasingly unlikely and experimental cooling systems and getting more and more frustrated with it. She heard the flight attendant talking about the flight schedule, but paid no attention. What to do with the fucking heat? How do you get it out?
    The possibilities were looking thinner and thinner: she almost didn’t notice that she was being spoken to, until the flight attendant touched her arm. “Everything okay, Dr. Johansson? You all set for takeoff? You look uncomfortable. Is the seat adjusting correctly for you?”
    “It’s fine. I was running