Saturn Run (34 page)

The
Celestial Odyssey
’s trajectory was very tight and its speed was way too fast. The Chinese ship would hit closest approach at over fifty kilometers per second. The Chinese would have to kill more than half of that velocity to get into a circular orbit. Plus, their trajectory was still inclined fifteen degrees to the ring plane, and even if they achieved orbit, they’d need yet more delta-vee to turn their orbit into one that brought them into reasonable proximity with the alien depot.

The
Nixon
’s nav crew said the
Celestial Odyssey
’s approach would bring them through the ring system out of view of the
Nixon
on the first pivotal pass. At the Chinese ship’s velocity, the most critical part of the encounter was going to be over in less than an hour. The
Nixon
wouldn’t be able to see the ship again until well after it passed periapsis.

Joe Martinez had a fix for that. He and Sandy modified two recon shells, fabbing lens extenders for the standard camera lenses. Martinez launched his do-it-yourself reconnaissance satellites into polar orbits, a half an orbit out of phase. That way, at any moment, one satellite had a view above the ring plane and the other below. The solution wasn’t perfect: the two cameras gave them only ninety-five percent coverage, but it would have to do.

By that “night”—ship’s time—the Chinese ship was still in free fall, closing in on Saturn faster and faster when it should have been decelerating. The nuclear thermal engines, monstrous as they were, still only provided a fraction of a gee. With dozens of kilometers per second to shed, the Chinese ship’s burn should have started hours before.

“They don’t have the reaction mass,” Fang-Castro told Crow.

“I don’t think so. They’re not going to make orbit.”

The
Celestial Odyssey
finally began its retro burn. They were as far from Saturn as the moon from Earth, but at their velocity, that was nothing.

Navigation: “Admiral? They’re not correcting their trajectory. Periapsis is dropping. They’re barely going to clear Saturn’s atmosphere.”

“Mr. Crow,” asked Fang-Castro, “do you have any reports of trouble aboard the
Celestial
Odyssey
?”

“No.” Crow amended himself. “At least, not as of two hours ago.”

“Comm, keep monitoring for a distress call,” Fang-Castro said.

Nav was losing her voice: “They’re still not correcting their periapsis! They’re going to hit the upper atmosphere!”

Martinez: “Oh hell. I’ve got it.” He looked bemused. “They’re crazy. They’re going to try aerobraking.”

Crow: “What?”

“They’re going to try to skim through the atmosphere deep enough that they can shed some velocity through friction. It’s been considered standard operating procedure on any Mars mission. But they’re nuts. Mars is one thing. Saturn’s another. Different atmosphere, different gravity profile, and, uh, three or four times the velocity? It’s nuts.”

Twenty minutes before close encounter, the
Celestial Odyssey
cut its main engines. Everyone looked at Martinez.

“Oh, yeah, that’s right. They’ve got to get the orientation and angle of attack absolutely perfect. Can’t come in tail-first, they’ll burn off their engines. Even if they get their attitude right, they can’t come in too shallow or they’ll skip along the top of the atmosphere like a stone on a lake. There wouldn’t be enough friction, and they won’t kill enough velocity. On the other hand, if they come in too steep, they’ll just be another meteor.”

The Chinese ship’s image on recon shell’s camera’s IR channel, a bare handful of pixels, had dimmed sharply when the engines cut out and dimmed even more as the engines cooled. Now it began to brighten again.

“Hope they tied down everything good. Aerobraking’s a bumpy ride,” Martinez said. “These boys have got some major balls, I can tell you that.”

Nav: “They are definitely slowing down. They’re shedding significant velocity.”

Fang-Castro: “Enough to put them in a closed orbit?”

“Nowhere near, but probably more than enough, before they’re done, to shed the excess velocity they piled on with that midcourse burn.”

Fang-Castro looked over at Crow, an unvoiced message going between them:
Maybe we dodged a bullet.

“Uh-oh, that’s bad,” Martinez said. Fang-Castro and Crow looked back at the display. Trailing the IR blip of the
Celestial Odyssey
, there were sparkles. Bright pixels that quickly winked out.

“Something’s burned off. Nothing should be burning off,” Martinez said. “They wouldn’t have an expendable heat shield. They figured something wrong. They broke something.”

“Comm, any messages?”

“Nothing, ma’am.”

“Hope they didn’t burn off their comm antennas,” Martinez said.

A minute or so later, the IR image of the
Celestial Odyssey
started to dim, as it left Saturn’s atmosphere. “Navigation, what’s their trajectory?”

“Still open, ma’am. They don’t have orbit, yet.”

Fifteen minutes passed, then twenty. No call. Nothing. Fang-Castro waited for the Mayday call. Nothing.

The image of the
Celestial Odyssey
suddenly brightened; simultaneously, Martinez called out, “They’ve started retro burn, again!”

Cheers broke across the bridge.

“Let’s keep the discipline, people,” Fang-Castro said, though she felt like cheering herself. It was space: it made a family of everybody.
The President doesn’t get that,
she thought.
She probably never would.

Zhang Ming-Hoa glanced at the date readout in the corner of his view screen: Tuesday, April 3, 2068. They were a billion, three hundred million kilometers from Earth and orbiting Saturn. That was the good news.

“Mr. Cui, cut those alarms off. They’re not telling me anything I don’t know and they’re making it hard to concentrate,” he said.

The captain of the
Celestial Odyssey
was a large, stocky man, with a reputation for being imperturbable, bordering on the impassive. He also had a reputation for being something of an irresistible force in the elite Chinese Yuhangyuan Corps. It went with his bulk.

The culture of the Corps favored
yuhangyuan—
astronauts—who were slight of build. In the early days of Chinese space travel, when each additional kilogram put into orbit greatly increased the cost and difficulty of a mission, this tradition had meant something. Small spacefarers made for smaller, lighter weight spacecraft. The Chinese space program could not have advanced as rapidly as it did with average or larger-than-average
yuhangyuan
.

That was decades in the past, but tradition changed slowly. The only group that put more of a premium on small size and weight were racing jockeys. Zhang’s imperturbability, merged with single-mindedness, had carried him through the training academy without any disciplinary incidents, despite the hazing of his classmates. The nicest nickname he’d ever had there was “big ox.”

His instructors, despite their skepticism over his physical suitability, knew officer material when they saw it. Faced with difficulty and even outright hostility, Zhang remained calm, quiet, and thoughtful. Very little fazed him.

For that reason, the bridge crew began to worry when he repeatedly muttered the obscenity
ta ma de
to himself. That was more what they expected of First Officer Cui. Cui Zhuo better fit the image of the
stereotypical
yuhanguan
: she was small and wiry, even by Corps standards, and entirely perturbable. Where Captain Zhang carefully pondered a course of action, First Officer Cui responded instantly and instinctively.

Her quick reactions were also what stood between her and a captaincy. Within hours of entering the academy, an upperclassman, noting her unusually slight build and reddish brown hair, dubbed her “Mouse.” Within a day that had changed to “Ferret,” and freshman Cui had the classes’ first disciplinary mark.

Her instructors noted her ability to command respect, but felt she needed thorough tempering before she’d be ready for command of her own. She wasn’t there, yet.

The alarms died, and Zhang said to Cui, “Well, we’re alive, anyway. For now. Is there any other good news?” He looked to Navigation. “Mr. Sun, what do you have for me?”

Sun checked her console. “We are in orbit about Saturn, sir. The aerobraking maneuver and retro burn were . . . successful.”

“You don’t look very happy, Lieutenant. I take that to mean it’s not a very good orbit.”

“I’m afraid not, sir. It’s very eccentric—we’re barely captured. Apoapsis will be, umm, about half a million kilometers. It’ll be about two days before we make a close pass by Saturn again and can do another retro burn to circularize our orbit.”

“Cui, you and Peng look even less happy than our navigator. Enlighten me.”

The first officer and helmsman had been worriedly conferring over his console. Cui looked up.

“Sir, the external tanks took a lot of damage during aerobraking. One or more of them may be repairable, but we’ve lost what reaction mass they still had. That’s about six hundred tonnes of liquid hydrogen gone. The internal tanks won’t provide enough delta-vee to get us into a proper orbit and rendezvous with the alien operation. We’re going to need to aerobrake again on the return pass, to shed enough velocity.”

Zhang’s mood turned grimmer than it already had been. “Those
ben dan
and their damned simulations. The plasma sheath was nowhere
near wide enough to protect the upside tanks. We’re fortunate the whole ship didn’t burn up.”

He looked around the half-empty bridge: another brainstorm of the groundpounders in Beijing. The decision-makers had decreed that stripping the ship of all nonessentials, both people and equipment, was the path to beating the Americans to Saturn. By the time the designers had gotten done repurposing the
Martian Odyssey
, they’d turned it into one of the most automated ships that had ever flown. The
Celestial Odyssey
could get by with half the operational crew of a typical ship of its size.

It was a damned stupid idea, in Zhang’s judgment. That judgment, he’d kept to himself. Another tradition of the Yuhanguan Corps: you not only followed the orders that were handed down, you made believe you were enthusiastic about them. Once you were in space, you could pretty much do what needed to be done, but until you got there . . .

Zhang knew it was the same for the Americans who went to space, and the Indians and the Brazilians, when it came down to it. It wasn’t culture, it was politics.

Those same politics had him here at Saturn. He’d seriously considered turning the assignment down. He’d been told the choice was entirely his. What they hadn’t had to say was that if he did turn it down, his career would come to an end. He’d shrugged, maintained his placid exterior, and thanked them for the glorious opportunity.

Well, it was a glorious opportunity, and it had gotten him to a part of the solar system he never in his wildest dreams imagined that he would see. However, it would be nice to live long enough to enjoy the memories, and he was starting to have some concerns about that.

Zhang said, “Well, nothing to be done for it. Mr. Cui, see how much repair work the crew can manage in the next two days and send me a report. You have the bridge. I’ll be in my office.”

He pushed himself free of his chair, his weightless bulk moving easily across the bridge and down to his private office. Once settled at his desk, there were plenty of other reports to be studied.

The external tank situation was, indeed, bad. Beijing had been crazy to order that desperate midcourse boost. He’d been even crazier to
pretend to believe their reassurances that the aerobraking maneuver would come off without a hitch. But their best experts had been so confident,
ben dan
every one of them, and he wasn’t going to disobey a direct order on nothing more than a sinking feeling in his stomach.

They’d cut free the downside reaction-mass tanks. Those would’ve burned away during aerobraking anyway and probably taken the whole ship with them. That lightened the ship, but cost them a third of their storage capacity. They still had the three upside external tanks, plus the internal tanks. That would provide them enough delta-vee capability to get home in a little over two years. It was well within the safety margin of life support and supplies. Control thought it an entirely workable plan that would get them to Saturn nearly a month sooner. They might even still beat the
Nixon
if the Americans suffered more bad luck. Zhang suspected the
Nixon
’s troubles involved more than luck.

Except, Beijing’s plan hadn’t worked well enough. The Americans had beaten them to Saturn by over a week. The preliminary damage report stated that the aerobraking maneuver had irreparably breached one of the external tanks; maybe the other two could be repaired. The downside bay doors looked to be inoperable; half their complement of runabouts and service eggs were useless unless they could get those doors open. That was going to substantially slow down refilling the reaction-mass tanks. He hoped the repair team could do something about the doors, and do it quickly.

Worst of all, they hadn’t arrived at their destination, not really. They’d still need to make another pass through Saturn’s atmosphere before they’d be able to match orbits with the alien operation.

Zhang jotted off an order to have the ship’s stores re-inventoried and a rationing schedule drawn up, in case things got worse. He was fairly certain they weren’t going to get better.

He and the management team ran on stims, and by the next morning, had a better idea of the range of their problems.

“The external survey crew says at least one of the external tanks can be repaired,” Cui said. “That’ll take at least a week. The second tank we’re not sure about yet, but I think we can do it.”

“We have to do it,” Zhang said, “so let’s enter that as repairable.”

The third tank was a complete loss.

“We can’t do anything with the tanks before our next pass through the atmosphere. Since the bay doors don’t appear to be damaged, most likely heat warping has jammed the releases. Let’s get Maintenance to focus on that.”

More stims, and a few hours’ sleep, and another day.

The morning brought an extended contact with Beijing. He’d started it with as complete a report as he could provide, including specific data that showed they’d hit Saturn’s atmosphere precisely as the groundpounders had recommended: and they’d still been badly damaged.

Mid-morning had brought a long message from the chairman and his scientific counsel. That had been an exercise in tap-dancing, everybody agreeing that nobody was to blame for anything, that everything had been done according to the best protocols.

That ended with the chairman turning to the screen and saying, “Zhang, you know how much I wish I could be there with you. I have nothing but admiration and respect for the way you and your crew have conducted yourselves. . . .”

When he’d finished, Zhang thought that he’d actually sounded sincere, and that he may actually have been.

Midday brought the inventory reports.

Zhang looked them over glumly. On the plus side, they weren’t going to run out of food or water. Hydroponics could provide them with a nutritionally adequate diet for an indefinite time. Oxygen and water could be regenerated. The problem was that spaceships didn’t have perfectly closed recycling systems; some chemicals were consumables they couldn’t produce on board.

Zhang supposed the mission planners had done well. They’d taken a ship designed for multi-month trips and fitted it to support a crew for years. Since they had no idea what would be found at Saturn or how long it would take to explore, they’d been able to squeeze in almost five years’ worth of life support. There was a good fifty percent safety margin over the optimum mission duration built into that.

The mission, though, was no longer running at anything like the optimum profile. If they couldn’t get back to Earth in three years, max, they’d be in trouble. They really needed the two salvageable external reaction-mass tanks to hold through the next aerobraking.

Zhang drifted from his office down the passageway to the bridge. Seventeen months in zero-gee had been a hard regimen to live with. He’d been skipping days in the gym while confronting their difficult situation, and the ship’s physician was going to beat him up if he didn’t get back on schedule.

He’d told the doc, “If the aerobraking doesn’t work, I’m going to die. So are you. Why spend our last moments worrying about whether our hearts would be healthy back on Earth? Once we know we’re going to survive, I swear, it’ll be an hour a day, every day.”

“I don’t believe you . . . sir,” the doctor said.

“Remind me to have you pushed out the air lock for insubordination,” Zhang said.

Now he floated into the bridge, strapped himself into the captain’s chair, and brought up the status screen. Everyone at their stations? Yes. All sections reporting everything that could be locked down, was locked down? Yes, except for the maintenance team in the downside bay. They’d been working on the door mechanisms and reporting good progress.

“Cui, tell Maintenance to have the team in the bay finish what they’re doing and strap down. This is going to get bumpy.”

Again.

He’d pressed the geniuses on Earth to provide a better set of navigation parameters for the next pass through Saturn’s atmosphere. They’d been both sympathetic and largely unhelpful. Their computer models still suggested much the same trajectory and angle of attack that had caused them grief on the first pass.

Chedan!

From their viewing ports, Saturn looked less like a planet than a landscape. The horizon line was nearly flat at this close distance, the cloud tops below them streaked with tawny shades of yellows, oranges, and dusty greens. Far ahead, the broad bands of the ring system filled
the rest of the sky, their knife-like precision contrasting sharply with the fuzzy fringes of Saturn’s atmosphere. The whole image looked unreal, an airbrush fantasy.

Cui said quietly, “Here we go.”

The ship began to vibrate; just a bit for the first few seconds, then more strongly. The view through the port was obscured by a faint reddish haze that quickly yellowed and brightened, and negative gee forces pulled the crew forward in their seats.

The incandescent plasma sheath made the ports almost too bright to look at. Atmospheric friction did its job, converting the kinetic energy of the
Celestial Odyssey
into heat and sound. The scream of the wind penetrated the hull as a rattling roar. For minutes that seemed much too long, the cacophony continued, then the ship bucked violently, and simultaneously a new alarm fired.

Through chattering teeth, Zhang called, “Helm, status.”

“We’re losing more pieces of the external tanks! I don’t think they’re going to hold.”

“Navigation, how much more of this?”

“We’re most of the way through, sir. Another two minutes and we’ll have shed enough velocity to handle the rest of the re-orbiting on our own.”

“If we make it that long,” Zhang whispered to himself. If they didn’t burn up. Even if they didn’t burn up, they might not have external tanks. If that was so, he thought,
We are screwed
.

Time dragged on, until it seemed impossible that the ship wouldn’t fly apart: but it didn’t. Gradually the buffeting diminished, the incandescent glow outside the windows dimmed, and the roaring wind quieted.

The
Celestial Odyssey
was free of Saturn’s atmosphere for a second time.