Saturn Rukh (34 page)

“How about fixing one of the lines and using the leftover coolant in the other two lines to top it off?” suggested Rod.

“A most ingenious suggestion, sir,” replied Seichi, but he wasn’t smiling as he said it, so Rod knew there was something wrong with his idea. “It was one of my first thoughts. Unfortunately, the sodium-potassium eutectic alloy reacts spontaneously when it encounters moisture, and there is a great deal of moisture in the clouds of Saturn. I have yet to think of a method whereby the mechbot could accomplish the necessary transfer without exposing the liquid to the atmosphere.”

By this time Pete and Chastity had joined them on the control deck. Dan and Sandra, who had stuck their heads out of their habitat doors during Jeeves’s warning, had gone back to sleep once they knew somebody was working on the problem. They knew it was important that some of the crew be fresh and alert when darkness came again in a few hours.

“Maybe we don’t need to fix the cooling loop,” said Pete. He turned and looked to the two pilots. “Can we make it with the fuel we have? I’d guess we have about fifty-one tons by now.”

“That would barely get us into low orbit,” said Chastity, rejecting the idea at once.

“He might have an idea there,” said Rod. “Jeeves! Suppose we stripped the ship of all nonessential items. How many tons of meta would it take to reach our refueling supply in Titan’s orbit?”

There was a pause as Jeeves went through the options. “Are you willing to go without washing water for the year-long trip back to Earth?”

“Sure!” they all replied.

“Can you go without habitats, bedding, hammocks, and all clothing except one jumpsuit?”

“Sure,” they all replied, although slower this time.

“Can you make do with one toilet?”

“Sure...” came the reply, but Pete was not part of the chorus.

“Then the mass of
Sexdent
can be stripped from fifty to thirty-six tons, and the amount of meta fuel needed at liftoff is approximately sixty-five tons.”

“Damn!” said Rod in disgust. “That’s so far from fifty-one tons there’s no use in working along that line any longer. Looks like we’ve got to find some coolant and get that reactor working again.”

“How about using another coolant to replace the ‘NAK’?” suggested Pete. “The chemsyns in my lab can make practically anything organic. How would you like a few dozen liters of ethylene glycol?”

“Only six liters of coolant would be required,” replied Seichi politely, but Rod noticed that Seichi still wasn’t smiling. Something was wrong with Pete’s idea too. “Unfortunately, the reason the sodium-potassium alloy was chosen was, not only does it remain liquid down to minus eleven C, it is highly conducting and can be circulated around the loop by an electromagnetic pump. Electromagnetic pumps contain no moving parts and require no physical access to the interior of the pipe containing the coolant. Both aspects contribute to long-term reliability and resulted in the selection of the alloy over other coolants, including ethylene glycol.”

“One thing ethylene glycol ain’t is conducting,” agreed Pete. “I could spice up some water with some ionizable stuff, like salt, to make it conductive.”

“For the electromagnetic pumps to work, the coolant must be highly conducting and remain liquid at the below-freezing temperatures the radiator fins experience here on Saturn,” replied Seichi. “I have looked carefully through the physical properties listings in Jeeves’s chemistry files, and the only known candidates are alkali metal alloys, certain gallium alloys, and mercury. Mercury would be ideal since it would not react with Saturn’s atmosphere.”

“Fat chance of collecting six liters of mercury up here in the clouds,” commented Chastity, her engineering brain trying hard with them all to find a solution to their problem.

“I have thought of one way to repair the reactor,” said Seichi solemnly. Again Rod noticed that Seichi wasn’t smiling. If anything he was looking even more somber.

“What!” exclaimed Pete and Chastity simultaneously.

Seichi replied slowly and solemnly. “Although I am unable to think of a method whereby Tabby could accomplish the necessary transfer without exposing the sodium-potassium alloy to the moisture in the atmosphere, I can think of a method whereby a human being could accomplish the task. This reactor is of my design. The design failed. The failure is therefore my fault. So it is necessary that I be the one to carry out the repair.”

“No way!” said Pete angrily.

“We can’t let you do that!” exclaimed Chastity, moving forward to touch him on the arm. “There
has
to be some other solution.”

“Chass is right,” said Rod, frowning. “Anything you can do, Tabby can do!”

“I think, in time, you will find my analysis is correct,” replied Seichi firmly.

~ * ~

In time, they all had to agree that Seichi was right. It took a number of days before all the alternate solutions were thoroughly examined by both the crew and hundreds of thousands of concerned people back on Earth, with suggestions coming in from South African youngsters new to the SolNet, to Brazilian auto mechanics working on the latest Grand Prix race cars, to nuclear engineers at reactor facilities in every major nuclear nation.

First, Sandra got Peregrine to leave the flock after a night’s climb to altitude and instead of joining in the hunting dive, to continue to climb to higher and colder altitudes. Although Uppereye had been able to elicit the cooperation of Lowereye for this departure from Peregrine’s normal way of life, it didn’t mean that Lowereye liked doing it. Lowereye had managed to learn a few words and he used them on this occasion. They had been climbing only a half-hour when Lowereye’s head flew its way up to the clearing to join Sandra and Uppereye. Lowereye was in charge of Body Peregrine, so he was experiencing the feelings of the body.

“Cold!” Lowereye announced. “Down now?”

Sandra looked up at the holoviewport above her, where Seichi stood at the scottyboard. “What’s the temperature, Seichi?”

“Minus twelve C in the air,” replied Seichi, “but only minus eight C on the radiator fins. There is still some residual heat stored in the mass of the reactor-radiator system. He needs to fly higher.”

“Up more,” said Sandra firmly, then added, “please.”

Lowereye activated his canards and flew his head back to its perch on the lower notch in Peregrine’s keel, where at least the head and eye would be partially protected by the warm feathers that surrounded the nesting site. As he disappeared from sight over the black feather forest canopy, Sandra heard the head rumble something, while at the same time the body below them echoed the rumble with many additional overtones.

“What Lowereye talk?” Sandra asked Uppereye.

Uppereye didn’t want to tell Sandra all of Lowereye’s list of complaints; how cold, hungry, tired, bloated, and bored he and Body Peregrine were, and how annoyed he was at being told what to do by an insignificant four-legged squinty-eyed blue-pink gizzard-worm.

“Cold,” Uppereye lied.

An hour later Seichi announced that the temperature of the radiator section had dropped to minus fifteen degrees centigrade. “The alloy should be frozen solid now. You can have Tabby start working on loop number two, Jeeves.” As he watched on the holoviewport, Tabby used the tools Seichi had made for it with the mechfab to cut the tubing of the two most damaged secondary cooling loops at their lowest points, clean the hardened sodium-potassium out of the end of the tubes, and crimp the tube ends tightly shut. To maintain the reactor’s neutron-scattering profile, the portions of the secondary cooling loops that passed through the heat exchanger section were also crimped off to prevent the alloy from leaking out once the reactor was heated up again. Next, the fins on the least-damaged cooling loop were cut loose at a straight portion of the tubing. The fins were warmed up with a meta torch until all the alloy dripped out. With the alloy gone, the fractures could be welded shut. The repaired fins were then reattached to the tubing with a mechfab-made butt-joint threaded tube coupling. The repaired loop now only needed refilling through the fill port at the top end of the radiator stack.

That night Seichi was just preparing his bed for sleep when he heard a tapping on his habitat door. He swung the door open to see Chastity—quite a bit of Chastity.

“I was wondering if you’d like a little company tonight,” she asked, reaching in a braceleted arm to scratch his cheek with her brightly colored long fingernails.

“I would be greatly honored,” Seichi replied. “But I am afraid the anti-radiation drugs and the sleeping pill Dr. Horning gave me have made me very sleepy. Perhaps tomorrow night?”

“Sure. Tomorrow night...” said Chastity, tears welling in her violet eyes as she gave his cheek a last pat and withdrew. Both of them knew full well that even if Seichi wasn’t killed on his mission, and managed to survive until “tomorrow night,” he would be facing months of pain, nausea, and probable death from the whole-body dose he would have received, and even if Doc pulled him through the first crisis period, he would likely die young from cancer.

~ * ~

Fifteen hours later as the dim sun rose behind the thick layer of water clouds high above, a well-rested Seichi with a deliberately very empty stomach stepped onto the “rungs” of the Hoytether that led to the now-cold reactor hanging below Peregrine. Although Body Peregrine also had a nearly empty gizzard and sent hunger signals to Lowereye, he kept the giant body moving in a slow circle as Uppereye had been making it do all night instead of climbing to altitude. They were well down in the atmosphere and the air was warm and moist. Occasionally the searching sonar from Peregrine’s wing would notice a larger-than-normal morsel of prey and Lowereye would smoothly adjust the trajectory of the giant body to swoop it into one of the rukh’s maws. The bits of food kept Petru’s hunger pangs down.

Seichi started down the Hoytether, followed closely by Chastity and Dan, with Rod and Pete staying on the wing edge, monitoring a well-anchored belaying line attached to all three of them. Seichi moved slowly and heavily. His backpack had extra bottles of gas attached to it, and the curved metal body shields on his helmet and underneath the torso of his saturnsuit added to his weight.

When they reached a point about two hundred meters above the reactor-radiator complex, Dan called a halt.

“My helmet dose meter is reading about five rems per hour,” said Dan. “Chass and I had better wait here for now. We’ll come down closer to help you up just as you finish the job.”

“Thank you for risking your lives to help me,” said Seichi. “If it had not been for my faulty design, you would not be placed in such a harmful position.”

“I told you once and I’ll tell you again!” roared Rod over the radio link. “You designed that radiator system perfectly for the job of floating under a balloon. Just because the fins weren’t able to cope with incoming jellyfish traveling at jetliner speeds is
not your fault!”

“You are very kind, sir,” replied Seichi. “But even if it is not my fault, it is still my duty to make the repair.” Taking a deep breath, he started down the last two hundred meters, moving as rapidly as he could to minimize his exposure time.

Tabby was waiting for Seichi when he arrived at the top of the three-lobed radiator stack. Precariously balancing on the top of the array, Seichi unfastened his safety line from a ring on the belaying line to Chastity above and replaced it with a hook leading from a package of folded gold-coated plastic film taken from insulating panels that had protected the walls of the meta factory from the heat of the rocket engines that had landed them on Saturn. He shook the package and a long tubular bell of glittering golden film fell all about him and down around the radiator stack and the reactor below, flashing brightly as mirrorlike film reflected his helmet light again and again until the whole interior of the bell was illuminated. Under the control of Sandra and Jeeves back on
Sexdent,
Tabby scurried down and around to unhook the skirt of the golden bell whenever it hung up on a snag. Tabby then drew in a drawstring at the bottom to turn the bell into a bag with a small exhaust hole at its base. Seichi reattached his safety line to the inside top of the golden bag, then removed two large tanks from the top of his backpack, and with a sigh of relief hung the tanks from the tubular frame that supported the radiator stack and opened the tank valves. The bag billowed out and stiffened as the tanks added their contents to the inside air.

“Dry nitrogen on. Humidity should be at acceptable levels shortly,” he reported brusquely as he moved quickly to his next task. He hauled up one of the two cooling loops that Tabby had previously disconnected from the reactor. Turning it end for end inside the closed confines of the bag was a complex task, but he had practiced it on a virtual simulator many times and completed the maneuver without tearing the bag or getting the radiator fins caught in the support frame or the fins of the other two cooling loops. He quickly opened the fill valve on the repaired cooling loop, then slowed himself down as he put the filling cone of the damaged loop up next to the filling cone of the good loop and slowly opened the valve on the damaged loop. He allowed himself a smile of satisfaction as he watched the bright silvery stream of sodium-potassium alloy trickle out and into the filling cone of the good loop.

The second loop went even faster because of the experience with the first one. As the stream of silver poured out and spiraled down the cone, Seichi clung to a glimmer of hope that he might get out of this without too much damage. The smile that was starting to appear on his face suddenly disappeared as the silver stream stopped and the last droplets fell through the hole in the bottom of the filling cone. He stared at the empty cone that was silently demanding more of the precious silver metal. He shook the cooling loop on his shoulder, but nothing came out.