Tears of Selene
Page 24
“Not much, I would think. The plants will die, any of them that are still in the ground. Thank heavens we never started a tree, for instance. But I don't know about the soil. Bacteria and such will die. But beyond that? No idea.”
Lisa looked at McCrary. “Is it really that important?”
McCrary shrugged his shoulders. “I honestly don't know. Part of me says it is, but I don't engineer according feelings, only data. Nobody's thought about this.”
“Well, we've got a lot of work to do up here. Are you going to be in Germany long, McCrary?”
“Until you land, Harel. Until you land.”
“You don't know how good that makes me feel,” said Harel.
The conversation continued on for quite some time.
***
One by one, the various subsystems of the Perseus were brought down to idle or shut off completely. The nuclear drive shock absorption system, unused since the Perseus warped into Earth orbit, was drained of fluids and secured with cabling out of the way.
The thorium reactor was carefully throttled over the course of a month, with the vital Uranium-233 slowly removed from the molten salt solution, purified, cooled until it solidified, then stored in special leaden cells. The thorium salt ran through the THOREX purification process, removing all high-level rad waste. Automatic machinery consolidated and vitrified it into impervious glass blocks. In a special equipment room, crew in spacesuits loaded the bricks into an empty radiothermic generator casing. The RTG was just like the one on the Lunar Disco. The electricity went immediately to power a long-life LED array. As long as the RTG converted the radiation from nuclear waste into electricity, and the LEDs kept converting the electricity to light, the Perseus would have a constant light source set approximately in the center of the fore hemisphere.
The fourth ERV glider had no propulsion beyond the small Mooncan engines for fine tuning. It had to be thrown out of the back of the Perseus, and only the Baby Flinger could do it. The Flinger normally operated directly from reactor power, and the reactor was shutting down.
Harel called back down to the surface.
“It's all like this, McCrary. We can't line up enough RTGs to power anything beyond lights. How do we run Baby Flinger?”
“The same way we tossed the Tank off the Moon. Make yourself a momentum generator.”
“I read about that—a disc spun up very fast, and a bunch of generators around it.” Harel paused, unsure how to continue.
Two seconds later, McCrary finished the description. “Correct. When you're ready to go, then the motors spinning up the disc turn into generators, and the momentum is pulled out of the spinning disc and becomes electricity again, only it’s fed directly into Baby Flinger and away you go. If the computer control is done well, the disc will have residual momentum left, and that might be enough to close the Cup after your leave.”
“Oh, yeah, the Cup. Damn, I know I'm going to forget something and regret it for the rest of my life.”
McCrary laughed, something so rare that nobody had ever heard it.
“Doncha worry, laddie. Just send down your checklist, and I'll go over it. Make sure it's as complete as you can make it. I'll get the rest of the crew back together so we don't miss a trick.”
Two seconds can seem like an eternity, Lisa mused.
“Thank you, McCrary!” The relief in Harel's voice was clear, even at six hundred kilometers away. “We'll get it together. Perseus out.”
McCrary turned back to Lisa. “We'll get them down safely, ma'am. Don't you worry.”
***
At long last, Harel and Dave Otheng performed a final walkthrough of the Perseus. Mothballing the giant habitat was quite a bit more involved than anyone could imagine. Most of what they had to do fell into a few categories:
Preserve volatiles
Secure base power for essential systems like the radio
Reduce restart time for the returning crew
Prevent catastrophic failures
After intense discussions both Earthside and on the Perseus, the soil was removed from large sections of the inner surface, ferried up to the central axis, and loaded into metal boxes. The air was pumped out of them, and a fine spray of liquid oxygen played over the contents. These boxes were then arrayed in one of the storage cells that once held cometary water.
“That way, if we ever get back up here, the soil can be thawed, the bacteria and mini-critters inside it revived, and we can mix it with the rest of the soil to farm again. Any dirt left on the inner surface is probably going to get sterilized from vacuum.” McCrary was quite positive about these procedures.
The shutdown of the Perseus took a little over two months. At the end, the solar cells covering the hollowed asteroid, all twelve and a half square kilometers of them, would become the main power supply of the ship. Debris impacts would destroy a lot of the panels, but in the meantime, the Perseus would be a laser platform in the sky, blasting any debris that came near with terawatts of laser light.
Most of the remaining crew had already embarked on the final ERV, the rest were systematically performing final shutdown procedures. Harel and Dave Otheng started at the central encampment, performing a final walkthrough of the camp area. The single RTG-powered 'theater light' was on and the overhead lighting remained, but already the habitat seemed filled with shadows.
“Place is giving me the willies,” said Harel. “But we still have to be thorough.”
Slowly, they made their way through the camp. Harel smiled at some of the touches the crew left—greetings to whoever entered this space next.
“You know,” said Otheng, “if we somehow manage to destroy ourselves before we ever get back up here, the next beings in here are going to be a bunch of aliens. I bet they're going to have an odd view of humanity.”
“Thanks,” said Harel. “Now I'm three times as spooked.”
Two hours later, they met at the controls for the elevators to the central axis. “All the other ones sent to the axis?” Harel asked.
“Yup,” said Otheng. “Ready for use. Of course, there's always the Helix.”
“True. I wonder if we should leave a couple of elevators on the ground.”
“Couldn't hurt,” said Otheng.
“Head up to the axis,” said Harel. “Get me a headcount on the glider. I'm off to drop one at each support leg.”
Otheng agreed and started for the nearest elevator.
Harel jogged around the support legs, circumnavigating the little world for the last time. Elevators set, he moved to the communications tent. Once inside, he took a memory strip from his pocket and loaded it into the console.
“All right, McCrary, this is for you.” He punched a button and loaded the program into the system. When the console blinked green, he smiled, removed the strip, and jogged back to the main elevator, taking it up to the central axis.
As he rode it, he marveled at the sensation of decreasing weight. Coriolis effect tried to throw him to the side of the cage, but Harel subconsciously thrust against it. A subway straphanger braced against the random thrusts of a moving train would understand completely.
The elevator slowed, and Harel pulled his body to the floor with the expertise borne of long practice. He smiled, remembering the crack on his skull the first time he rode the elevator up.
He found Otheng at the platform, floating effortlessly in the freefall conditions at the center of their world. “All up?” Harel asked.
“All present,” said Otheng. “The last of the closeout crew are suiting up.” A low roar, almost like a jet engine starting up, invaded their senses. “Let's go, they started up the pumps!”
Harel nodded, and they both made their way to the changeout room. Behind them, the roar increased in intensity, and Harel felt a perceptible breeze along the axis.
“Better hang on before you get sucked into the pumps!” shouted Harel. They gained the relative safety of the changeout room; the roar cut off as the hatch slammed shut.
�
��That could have waited until we were in here,” complained Otheng.
“They're anxious to get back,” said Harel mildly. “So am I.”
They were already in their skintights, but they still had to don the environmental units, helmets, and gauntlets. Harel grew conscious of a great emotion filling his being. Part sadness, part eagerness, it was a swirling mixture of opposites that threatened to disorient him.
“Good way to get killed,” commented Otheng. “No, I feel it too, Harel.”
“You're right,” said Harel. “All right, checklists, by the book.”
They spent an unusual amount of time on the suitup checklist. Harel waited with his helmet off, just to check on Otheng's own seal. When the engineer gave him a thumb’s up, Harel looked at his helmet, spun it in his hands a few times, and took a deep breath of the thickening atmosphere in the changeout room. He put his helmet on, and locked it to his neckring. When he exhaled, it was into an atmosphere of his own and not one created by The Farm.
“Another few minutes of screwing around, sir, and we'd have had to hit the oxygen feed,” observed Otheng. “We're never going to get home at this rate.”
“Insubordination,” said Harel. “Walk the plank.”
Otheng mimicked walking a plank in microgravity. “Finish the checklist, sir, so I can spill the air in here.”
Harel performed the checks, then gave Otheng a thumbs up. “Go ahead,” he radioed.
Otheng punched a control labelled Spill to Fore Chamber. A strong thunderclap smote the astronauts, followed by a loud shriek as the air inside the changeout room roared away into the lower pressure of the forward chamber of Perseus.
Otheng shrugged. “Sorry. I didn't think the pressure differential would be so strong. We still have to airlock out.” He hung a sign over the spill valve control that said Close Me, then with a slight push, floated over to the airlock leading back to the aft chamber.
Harel took a final look around the changeout room, saw nothing amiss, then followed the engineer out of that part of the Perseus. He wondered idly if the changeout room was ever going to be used again.
The outside of the airlock led directly to the flexible embarkation tunnel clamped to the airlock of the fourth glider, built five years previously under the watchful eye of McCrary. Otheng waited at the junction.
“We're unhooking this too, right?”
“That's the sequence,” said Harel.
It took them a few minutes, but they detached and stowed the tunnel, ready for use if anyone ever made it back up to space. The two men floated over to the massive glider, built to seat one hundred spacesuited crew and holding half that many.
Harel held the small piece of sheet steel while Otheng welded it into place, sealing the last opening in the large box that held the glider.
Harel waved Otheng through the airlock before him.
“Right—last man,” said Otheng. “Don't go down with the ship, Captain.”
“I could still make you walk the plank,” murmured Harel.
Otheng gave him a half-hearted salute and cycled through the one-man airlock.
“No romance in your soul,” said Harel after turning off his microphone. With a slight push against the side of the glider, he spun a full three-sixty around his vertical axis, taking a final look around the Perseus. “What a fantastic place,” he said. “Seven wonderful years.” The door to the airlock opened, and he climbed aboard.
He swam to the cockpit. “All aboard?” he asked.
“Kinda late to ask, since we've compressed all the air in the fore chamber,” said Gus Zumwalt. “But, yes, everyone's aboard.”
“Where are we with the countdown?” asked Harel.
“Relax, sir. We've got twenty minutes. That is, if we want to land around Florida, like the other three.”
“Of course we do. Twenty minutes. Who's controlling?” asked Harel
“UNSOC-DRC. Friend of yours on the horn, too.”
“Do tell,” said Harel. He toggled channels. “Perseus calling UNSOC-DRC. Come in, UNSOC.”
“This is UNSOC Disaster Response Center,” said the unmistakable honeyed tones of Celine Greenfield. “I will be CAPCOM for you until Entry Interface.”
Harel relaxed. Everything was going to be all right.
***
After the incredible shove that the Baby Flinger gave to their glider-in-a-box, Harel left the flying to Gus Zumwalt. Unlike some of the pilots for the previous three gliders, Gus had some actual cockpit experience. He had flown as the weapons support officer on a two-man fighter-bomber. While he never actually piloted a plane, he certainly knew his way around an aircraft, which was more than any other of the fifty people remaining could claim.
“Remember, Gus, you've got to have the trim correct,” said Celine. “We want you back safe.”
“Roger, UNSOC,” said Gus. “Let me know when you get telemetry.”
Harel reminded himself that UNSOC was reliant on line-of-sight radio, and there were no receivers in the middle of the Pacific Ocean along their flight path. Their track over the ground was from west to east, peaking at some twenty degrees north and south of the equator.
Harel looked at the forward monitor to darkness. He was puzzled for an instant, then he remembered: Right, we're still in the shielding box. Maybe I should remind Gus it's getting time to jettison it.
At the same moment, Gus casually flipped a switch. The monitor flared with a reddish-white light, and the front of the sheet metal box which protected their flight from Perseus to the top of the Earth's atmosphere was blown up and away. Wisps of atmosphere, even at the one hundred and fifty kilometer level, was enough to slowly pull the box off of the glider.
“UNSOC, have blown the shield box, and it is slowly falling astern,” said Gus.
“Roger.”
“Initiating pitchup to entry attitude,” announced Gus, toggling a program in the autopilot.
The view in the monitor moved, with the Earth dropping below the bottom of the frame as the nose pitched up. Gus grabbed a little pad and wiggled it, exactly like a driver adjusting the side mirrors of a car. The belly camera moved and Earth swam back up into the frame.
Gus took his hands off of the controls. It wasn't required—after all, the autopilot was in charge during this phase of reentry.
The image of the Earth shuddered violently, just as a banging noise transmitted through the structure of the glider. Simultaneously, master caution lights sprang into angry red life.
Gus cursed once, sharply, then thumbed the microphone. “UNSOC, we have a problem.”
Silence.
“Call them, Harel. I have a ship to fly.”
Harel tried to call UNSOC, but static was his only answer. He looked over Gus's shoulder as the man tried to make sense of his instrument readings.
“Lost the MoonCan engine in the nose,” said Gus. Aft thruster kept pushing, now we're pitched too high for reentry. Damn, damn, damn.”
A feeling came over Harel, as if a heavy blanket was thrown over him. He started looking at the control panel for the g-meter. The needle stood at 1.3.
“Yeah,” said Gus. “We're going back up.” Even as he said so, the meter was slowly winding back to the zero mark.
“Hang on, this is going to be a little violent.”
Harel realized that he’d heard the pilot on the common radio channel. Gus flipped off the autopilot, wrenched the stick hard right for a couple of seconds then twitched it left for a second and stopped. The Earth now stood at the top edge of the frame, ascending upward. Gus waited for it to disappear, then performed the maneuver again. After a few seconds, the Earth crept back up the frame from the bottom. Gus looked at other instruments, then hit the master switch to cut power to the MoonCans.
“I hope that's all I have to do,” said Gus. Again, the broadcast was on the common channel.
“Looks like we blew the MoonCan motor on the nose of the craft. The rear one kept firing, and that pitched us up too high. We bounced off the top of t
he atmosphere, and we're about thirty kilometers higher. I'll give you more information when I've got it. Gus out.”
Gus turned around and faced Harel, holding up two fingers. Harel switched the channel.
“Bad, Harel. We're too high. We're going to reenter, there's nothing that's going to prevent that. But it's not going to be in Florida. I'm not sure where we're going to end up. Sure hope it's not over land.”
Harel nodded. “Anything I can do for you, besides calling for UNSOC?”
“Nope. Might want to try them again. We're probably pointing in the right direction now. “
Harel agreed and tried calling again. It took him fifteen long, anxious minutes until he regained contact.
“We have you high and past the entry cone.”
“Roger, UNSOC,” said Gus. “Lost the nose MoonCan and the aft one kept thrusting until it ran dry. Had to do some fancy footwork. Here are my coordinates—”
“No need—we've got telemetry. We're running your energy balance through the computers now. Recommend you do a minimum-energy reentry. Don't know when you might need a bit.”
“Roger, UNSOC,” said Gus. He began punching data into the autopilot program on the commpad.
Harel realized with a jolt that he had not once looked back at the Perseus. Then he realized that the shielding box would have prevented it anyway.
“Pilot, this is McCrary. Is Commander Mazzo on this frequency?” Harel waved at Gus and took the call himself.
“This is Mazzo. Glad you're there, McCrary,” he said.
“How is your craft?” asked McCrary. “Wait, what do you call your craft?”
Harel experienced a most indescribable feeling. If he was on the ground, he would have described it as if all the blood was leaving his face. But since he was still in freefall, the blood wasn't going anywhere. That didn't mean the feeling was invalid.