Saturn Rukh (46 page)
“Might as well be comfortable on our deathbeds,” said Rod grimly as he had the crew reinstall the habitats. He also knew that the activity would help keep their minds off their predicament. Sandra also helped by insisting that everyone take turns helping her take more images of the rings and moonlets as they passed over them on the way out. The scientists on Earth helped by giving them targets to look for. They had carefully scanned the ring images that Sandra and Dan had transmitted back during their climb down the rings and had predicted the locations of a number of “shepherd” moonlets. Soon the catalog of the “Moons of Saturn” exceeded one hundred, many of them now named for inhabitants of Saturn. In addition to names such as Peregrine, Falcon, and other members of the rukh flock, there was one moonlet seemingly completely covered with small craters of various different sizes that now sported the name “Millistoma.”
~ * ~
Two days later, they had left the rings behind, and Chastity and Dan were up at the science console taking high-resolution pictures of the region around the trailing Trojan point that they were approaching. Rod and Sandra were having a dinner together down in the galley.
“Haven’t you found anything that can get us out of this spot, Rod?” pleaded Sandra.
“Doesn’t look good,” said Rod with a shake of his head. “We’re in an elliptical orbit with the apogee at Titan’s orbit, but Titan isn’t going to be there to stop us. After we come down, the perigee penetrates the upper atmosphere, and when we hit that, we burn up.”
“Can’t we fire our rockets?”
“As I said before, we can,” said Rod. “And unless Chastity or I can think of something else to do with the remaining fuel, I will have her do an apogee bum, which will raise our perigee slightly and keep us from burning up. But I can’t raise it too much, or in our next pass we’ll smack into the C or D ring. Even if I stay below the D ring there’s a four percent chance we will hit a rock spiraling inward from the D ring. Even if that means that our chance of survival is ninety-six percent, those odds are multiplied each seven days, as we go through the ring passage segment of the orbit. Multiply that probability up over enough weeks and we’ll be holed before a rescue mission gets here. Even if we are lucky enough not to be holed, we’ll soon use up all our meta. Right now it looks like we’ll either starve or freeze to death. Compared to those lingering deaths, a fast hypersonic burnup doesn’t sound like a bad way to go.” “What are we going to do!” wailed Sandra, looking up to him for comfort. “I’m scared!”
“Why don’t we two go upstairs and take a little break in my tube,” said Rod, putting a comforting arm around her. “I’ve got some laser juice stored there. We can have a little party, just the two of us, and think about something else for a change.”
As he followed Sandra up the passageway, he looked up at Chastity and Dan, scanning the space ahead of them with
Sexdent
’s telescope. Rod had wanted to leave the telescope behind, but Dan didn’t have the proper tools to remove the specialized bearings from the welded frame.
“We’ve found some icebergs at the Trojan point,” Chastity said. “Should be easy enough to avoid them.”
“Can’t we use those icebergs to stop?” asked Sandra, turning around on the ladder to look down at Rod floating by one hand behind her.
“Won’t work,” said Rod. “Chass and I looked at that long ago. Let me show you.” They ottered to the top of the ladder and drifted over to Chastity’s console. After admiring the picture of the iceberg, Rod punched some icons and brought up a diagram and some tables.
“When we arrive at apogee, we’ll be traveling at 1.7 klecs, while the icebergs at the Trojan point will have Titan’s orbital velocity, which is 5.6 klecs. We’ll be going 3.9 klecs slower than Titan. It would be nice if we could use the tether to just swing around the iceberg. We would end up going the other way, only this time we’d be going 3.9 klecs
faster
than Titan. We’d soon catch up with it, and if we aimed our trajectory right, we could spiral into Titan’s gravity well, use the last bit of our fuel to do the perigee burn at Titan, as we had originally planned, and come out on a trajectory that would float us off to our return tank full of meta at the leading Trojan point.”
“Then why don’t we do it that way?” asked Sandra, puzzled.
“Playing ‘swing around the iceberg’ at the end of a two hundred-kilometer tether while you’re moving at a velocity of 3.9 klecs means pulling nearly eight gees,” interjected Chastity. “Although we humans can take it, the tether can’t. Can’t be done that way.”
“We also looked at using the rockets to slow
Sexdent
down before we start the swing. If we lower the initial velocity enough so the tether isn’t snapped by the centrifugal acceleration, then there isn’t enough fuel left to do the perigee burn at Titan. It just goes to prove the old rocket pilot adage that it’s best to do your bums in the deepest gravity well you can find.”
“How about slowing
Sexdent
down using the electromagnetic brake on the tether—like we did at Helene?” asked Sandra.
“Won’t work,” said Chastity. “Remember? We did those calculations long ago, before takeoff, when we were trying to figure out a way to stop at the leading Trojan point. If we tried to slow down from an initial velocity of 3.9 klecs, the radiators would melt instantly. Even if we used the rockets to slow
Sexdent
down as much as we could before starting the braking process, the calculated radiator temperature is above four thousand kelvin, and tungsten melts at thirty-four hundred. That option is so far from being feasible, I stopped thinking about using it long ago. Tether braking is only useful when you’re moving at low velocity, like coming to a stop at the iceberg that’s shielding our return tank.”
“But before, when we were trying to find a way to reach the fuel tank at the leading Trojan point, we were trying to brake all the way to a stop,” said Sandra, not wanting to give up. “Now that circumstances have sent us to the trailing Trojan point, we no longer want to stop. We want to leave with enough velocity to get to Titan and the leading Trojan point. Have you tried combining braking, swinging,
and
rocket bums?”
Rod looked at Chastity, who looked back at Rod.
“Out of the mouths of babes …” said Rod. He turned to Sandra, took her head in both hands, and gave her a big kiss. “And what a babe she is!” Leaving Sandra floating in midair he turned and settled himself down at the commander’s console to join Chastity as they took Jeeves through another round of trajectory calculations. Dinner that night was a celebration, with Pete staying sober enough to prepare cherries jubilee again for them.
“Chass and I are calling it Sandra’s ‘Swoosh, Slide, and Swing’ maneuver,” explained Rod, sipping his after-dinner coffee from his squeezer. “It’s complicated, but if everything works, we’re on our way home.” He held up an ice cube rescued from his pre-dinner “scotch on the rocks” squeezer, and a baking powder biscuit saved from his special southern fried chicken dinner. The biscuit had a hole poked out of the center. He carefully placed the ice cube in free fall. “This is the iceberg at the trailing Trojan point.” A meter away he placed his globular coffee squeezer in midair. “Here is Titan ...” A meter farther he carefully placed the donut-shaped biscuit so it too was floating. “And here is our return fuel tank with the meta we need to take us home.” He took a cherry out of Sandra’s cherries jubilee and held it between his fingers. “And this is
Sexdent.
“
He moved the cherry below the “iceberg.” “As
Sexdent
and the iceberg pass each other going in opposite directions, I first use the rockets to slow down
Sexdent,
in the process using up nearly all of our fuel.” The motion of the cherry slowed. “Then Chass fires the penetrator …” From the hand holding the cherry he pulled out a length of dental floss he had been palming and brought it up to the ice cube. “And spears the iceberg. But only half the tether has been deployed.” Holding the floss taut, he started to swing the cherry around the ice cube.
“Sexdent
then starts swinging around the iceberg, but instead of keeping the tether locked, Dan allows it to unreel, while using the brake to extract energy from
Sexdent.
“ He moved the cherry up above the ice cube, pulling out more floss as he did so. “It takes us about two-and-a-half minutes to swing around the iceberg. By the time
Sexdent
has completed a half-circle, braking all the time as the tether is getting longer, it is moving much slower than it did when it arrived, and is going in the opposite direction—toward Titan.” He moved the cherry over to the squeezer. “It arrives at Titan a few days later, dives down the gravity well, I give a small perigee bum”—he twirled the cherry around the squeezer and then moved over to the biscuit with a hole in it—”and we end up at our fuel depot at the other Trojan point, where one tiny little jet burst brings us to a stop.” He looked around at his crew. His face, usually furrowed with the burdens of his command responsibility, was, for once, calm and at peace.
“But we’ve got a lot to do to get ready,” he ended, taking charge again.
~ * ~
A day later they reached the peak of their escape trajectory from Saturn. Everything was in readiness to carry out Sandra’s “Swoosh, Slide, and Swing” maneuver. The habitats were stored, everyone was in their acceleration couches, the radiators for the electromagnetic tether brake were unfurled to the sky, and Tabby had the last penetrator checked out and ready in the open port of
Sexdent’s
nosecone. Rod watched the display on the commander’s console as the blue dot that indicated the approaching iceberg rapidly caught up with the much more slowly moving red dot representing the position of
Sexdent.
Rod lifted up on the joyball in his controller and the main engines at the rear of Sexdent ignited again. The red dot on the screen grew a reddish-purple tail and started moving faster in the same direction as the iceberg dot.
“One point five ... one point six …” counted Rod, then pulled the joyball down. “One point seven klecs,” he finished, his voice echoing in the silence that followed the loud roar of the engines. “That’s nearly all our fuel. It’s your turn now, Chass.” He switched the joyball to vernier jets and turned the capsule around so it was facing back along their direction of travel. In the viewport windows above them, the crew could now see the rapidly approaching mountain of ice. The holoviewport above Chastity grew partially opaque as crosshairs appeared, superimposed on a long-distance image of the iceberg. Chastity, her right hand in her controller, used the joyball to align the cross-hairs on the target, then activated an icon with her pinky. There was a swooshing sound from the nose compartment above. Spouting a reddish-purple meta flame from its rear, the penetrator jetted off into the distance. While Chastity guided the penetrator, Dan read off the length of tether deployed.
“Ten kilometers ... twenty ... thirty …”
The holoviewport above Chastity now showed the view from the video camera in the nose of the penetrator. The ice mountain began to fill the screen as Chastity focused the crosshairs on the center of a medium-sized crater.
“Ninety-five ... one hundred ... and five ...” continued Dan.
“Got it!” yelled Chastity as the screen above her went black. “Now hold!” she pleaded in a softer voice.
It was now Dan’s turn. Although Chastity had operated the electromagnetic brakes previously, handling both the tether and the brakes simultaneously required two hands, so now she controlled the tether while he controlled the brakes. Watching the displays on the scottyboard carefully, Dan slid the tether brake icons down with his fingers until the acceleration level in the capsule built up to almost four gees.
“If the penetrator pulls or the tether snaps, this’ll be the time,” muttered Chastity. The acceleration level slowly began to decrease as the tether rapidly unreeled, giving their swing around the iceberg a longer arc. Above them arose a brilliant light from the now whitely glowing radiator fins sticking out from the nose of the ship. The viewport windows darkened, protecting their eyes from the intense light, but soon the heat from the infrared began to make itself felt through their clothing.
“Three thousand K …” said Dan, reading the temperature indicator on his display, “... thirty-one hundred ... thirty-two hundred.”
“Isn’t that getting a little high?” asked Rod, slightly concerned. “The melting point of tungsten is thirty-four hundred. I thought we were going to keep the radiator temperature below thirty-one.”
“That was the plan,” muttered Dan. One of the three fingers on his hand made a tiny adjustment to its icon that controlled the amount of electric current flowing to that radiator. Above each icon were indicators showing their temperature and current ratio. “But one of the radiators isn’t working right and I’m having to ask the other two to carry more of the load so the braking power stays constant—”
“You’re making the right decision,” Rod assured him. “If we leave this iceberg moving too fast I won’t be able to stop us with the fuel we have left.” The seconds passed slowly. The acceleration level slowly fell as the temperature inside the capsule rapidly rose.
“Just one more minute,” said Rod, trying to encourage his crew. “Then we can turn this sauna off.”
The light above them grew until it was brighter than the Sun ... Suddenly there was a flash and then darkness— “Brake, Dan!” yelled Chastity. “We’ve not completed our swing!”
“Brakes are gone,” replied Dan grimly. “And I can’t activate the tether clamp while the tether is moving. Just pull off the nosecone if 1 tried. That’s why the end of the tether isn’t tied to the reel.”
