“Stop it!” she shot back at him. Louder than she meant to. “We'll get back. That's not a problem. When the bridge opens we go back and tell them what's going on. They'll send a team through, or something, a whole protospike maybe to push Betty out of harm's way. They'll open it in—” she glanced at the linkage chronometer “—two hours and forty minutes. Just hold on.” His cough sounded in stereo in her ears, but he was calming himself. Muttering military relaxation mantras.
“Ceevee, from the Doppler shift, estimate our speed. How much time do we have before we reach the mass?"
“Blue-shift estimation at seventeen thousand kilometers per second. Tidal force threshold approached in two hours fifty-four minutes."
She checked the chronometer again. Two hours and forty minutes until transit. Her lips moved several times but didn't form words. Fourteen minutes. They'd make it home fourteen minutes before the gravity tore Betty apart. Fourteen minutes to scramble some kind of team, come back and push Betty out of harm's way.
“That gives us what?” said Loránd. “Thirteen, fourteen minutes? Talk about cutting it close.” He was trying to sound flippant, trying to negate his panic, but his breaths were short and uneven.
Fourteen minutes. She looked at the linkage terminals before her. It could be done. How quickly could Darkside assemble a team? No time for a proper protospike launch—but they wouldn't need one. The drag on Betty would actually help. Five, maybe six minutes if alert crews were ready. That left eight minutes for them to use whatever heavy-lift thrusters they could pull through. If they could bring a whole protospike through in time, it would have power enough to shift Betty. At seventeen thousand kilometers per second, even a moderate nudge would make a huge difference. It could work. They'd also need to recharge Betty again and Tessa wasn't sure the Darkside generators could rev up enough to fire another gamma burst in just five minutes. Again, it would be a mad scramble on Darkside, but it could work.
She started reprogramming the timers, deleting “thirty days” and typing the digits for the scant five minutes—
No, wait.
Her gloves hovered over the blinking terminal.
“Lor,” she said. So expressionless it could have been her electronic voice.
“I'm here."
“We can't open the bridge."
“What? I've got All Green across the board. Even—"
“Lor,” she said harder. “We can't let it. The gravity. We don't feel it because we're freefalling toward it, but if we open a wormhole back to Darkside...."
Gravity. The pull of eighteen-point-seven solar masses would travel right through the bridge. Radiate out of Alice. Darkside would probably survive, but larger masses, like the Moon, like Earth, what would happen? Twenty-one seconds of unnaturally bent space rippling out of Darkside at the speed of light.... When they had out-transited there was probably some gravitational effect felt even then, though it would be a long time before anyone understood why. But they were falling toward the mass at almost twenty thousand kilometers per second, and the gravity's strength would rise exponentially. In the four hours between transits it would be hundreds of times stronger. How much damage would eighteen-point-seven solar masses do in twenty-one seconds? Earthquakes? Tsunamis? How many would die?
Neither of them spoke, but Loránd's staccato breathing sounded close in her ears. For the barest of seconds her vision wavered as she comprehended—felt—the emptiness around them. Felt the trillions of kilometers of freezing nothingness between them and home. She thought of her dad, sitting in the pilot's lounge, of watching his face when she said, “utterly, unchangeably, alone.” Even with eyes closed, she could feel the sky around her getting grayer and grayer, as more stars quietly filled in the back rows to watch.
“Tess?"
“Yeah."
“You're the physics guru,” he said. “Get us back.” And then, quieter, “You gotta get us back."
She paid out the tethers and walked a few meters to the set of propulsion terminals. She knew he could see her in the floods. She studied the terminals, the full batteries, started running figures in her head. The weight of the ring. Reaction masses. Engine thrusts.
“Ceevee,” she said, “shut down all of Betty's engines. Loránd, confirm."
He didn't question. “Ceevee, shut down Betty's engines."
For the first time in eighty years the terminals showed the engines shut down. Loránd coughed, and again asked Ceevee to clear his faceplate. She was glad she couldn't see him past the floods.
“Hey Tess? Tess, I can't stop shaking."
“You were talking about Thanksgiving before. They don't celebrate that in Brazil. Where'd you grow up?"
“I grew up in Campinas but my family moved to California when I was ten. Marith was born in California, too, but we didn't meet until Darkside. She's just about done with her doctorate, did you know that? Less than a year now, with honors, too. We've been thinking about renting a place on Luna to start a family until my tour here is over. Then I think we both want to go back to Cali. Growing up on the moon would be too lonely for a kid."
He talked as she worked. She took an exacting inventory of everything Betty had on her; everything from the power of individual engines to the mass of her rivets.
* * * *
When she'd escorted her father through the corridors of Darkside at the end of his trip, he bumped along in the way newcomers to zero-G always did. She helped to steady him as she drifted, easily, needing only occasional brushes with the corridor's rungs to move herself. She guided him toward the shuttle port, her free hand holding his small bag of belongings. “Your mother was right,” he chuckled as he reached both hands out toward an approaching wall. “She would have hated floating around like this.” Tessa pushed gently and eased him through a circular door.
He'd watched her on a transit. She'd had him in the back of her mind the whole time she'd been away on Betty. It seemed an easy transit that time; seemed warm instead of cold. Not so far away. After the perfunctory in-transit medical exam she found him in the waiting room. He was smiling but she could tell he was nervous and had probably had more than one drink in the pilots’ lounge during her four-hour absence. He never mentioned it, though.
When they'd floated into the docking hall, it bustled with people prepping the shuttle. She handed her father's bag to a nearby worker, who did a double-take before stiffening and yelling, “Pilot Commander on deck!” Three dozen activities came to a halt as men and women of all ages and ranks suddenly anchored themselves and threw sharp hands to their foreheads. Her father looked around for several seconds before realizing that Tessa was the only one standing casually. A smile crept into the side of his mouth. “As you were,” she said, quietly but directly. The bustle instantly resumed. He looked from her to the dock loaders and back to her, shaking his head with a widening grin. She hugged him, finding that for no reason at all she still only came up to his shoulders in zero-G. As he turned away toward the shuttle hatch, he threw her a quick look of high eyebrows, mouthed, “Wow,” and fumbled his way into the port. She stayed to watch until the shuttle gracefully broke orbit.
* * * *
Something was wrong.
She looked down at the propulsion terminals as they finished their inventory. Everything on Betty was functioning normally. But something had...
Loránd had stopped talking.
“Lor?” she whispered. Her tongue moved to form his name again, but she couldn't say it. She tightened her jaw and whispered, “Ceevee, give me internal cam.” The cabin sprang to view. Rotated as her eyes moved. Loránd was sitting, arms floating before him. Behind his faceplate, his eyes were closed. Mouth half open. Red lights blinked inside his helmet.
“Ceevee,” she whispered again, “shut down my holodisplay. Shut down all heating to Commander Delago's suit."
She was alone.
* * * *
She paid out the tethers and walked around the outside of the ring toward the CV. Soft clicks as her sole
s adhered to Betty's rivets. The creaking of her suit. Breath against her faceplate. When she got to the CV, she stepped gingerly around the floodlights and saw Loránd under the canopy in the rear seat. She ordered the cabin depressurized and pulled coolant hoses out of the CV's engine. She opened a pair of valves on the chest of his suit and jerked when a mist of air sprayed out and crystallized. The crystals were red. She twisted the hoses hard into the valves, tugging his limp body as she did. His arms seem to wave her off. “Ceevee, reroute your port engine coolant to bypass engine completely.” She stopped as her voice cracked. “Run the coolant to cooling fins only, can you do that?” Ceevee confirmed, Loránd's suit suddenly swelled, and coolant flooded his helmet, bubbling into his mouth. It would cause complete chemical burns and he'd be blind when resuscitated. She settled his drifting arms into his lap. The coolant pulsed in them.
The canopy closed as she stood again on the ring. She made sure her boots were secure before filling her lungs and screaming inside her helmet until her ears rang.
The stars looked on quietly.
She sniffed and switched Ceevee's microphone back on. “Ceevee, how long until link-up?"
“One hour thirty-two minutes."
“Count down time to link. Standard intervals.” She sniffed deeper and looked at the starfield ahead. “Ceevee, highlight the singularity.” A blue crosshair. Her teeth ground into themselves. “Show me a graphic of our intersection with it.” She started walking back up the ring as Ceevee displayed an image on her retina of a curving line that swung hard around a small dot before turning back and colliding with it. Betty wouldn't hit the black hole straight on, but she'd be torn apart by the gravity as they arced around it.
“Ceevee, calculate the necessary force needed to divert Betty into escape orbit around mass without incurring destruction-level tidal force."
“Two-hundred-thousand kilonewtons."
Tessa winced. The ion engines weren't even close. She reached the linkage terminals, noticed the crystallized blood from her nose on her glove and scraped it off.
“Ceevee, from Doppler shift, what's our current speed?"
“Twenty-one thousand kilometers per second."
She looked out ahead.
“What if I swivel Betty around? What if instead of Betty facing the direction of pull, it faced away? What effect would that have on gravity radiating out of Alice on link-up?"
“Space-time curvature would travel through bridge in same measure."
Tessa had expected as much, but she was thinking out loud. How else to stop gravity radiating through the tunnel? Sudden acceleration of Betty during transit. Abrupt and short-lived. Acceleration mimics gravity, so thrusting into the gravity well.... Maybe open the bridge only a tenth of a second if she used CV's ejection seats to fire them through at the perfect moment. She had Betty's full batteries, engines, computers, the CV with all its equipment. A powerful thrust could stretch the wormhole itself and minimize the effect. She asked Ceevee. Only about a 13 percent decrease.
“If we use the ion engines at their full thrust, I mean full regardless of safety limits, and add to that the CV's engines at full, and design something to use the rest of Betty's stored energy in a single explosive discharge, how much reduction can we get?"
“Sixteen percent reduction in gravitational transduction."
“Come on...” she whispered. She looked down to the CV's floods, thought of the precious energy they were wasting. “Ceevee, shut off your floodlights.” The lights winked out and the sudden darkness caught her off-guard. Betty, the CV, even her own hands became sudden silhouettes of black as the starfield all around her rushed in. Vertigo was palpable, as if she was being spun. Somewhere behind her one of those tiny stars was home. “Ceevee, turn the floods back on!” she yelled, then amended with, “Just one, at a tenth brightness.” A flood flickered and complied. The stars stayed at bay.
Darkside knew something had gone wrong with her launch. If they couldn't reconnect on schedule, maybe they'd keep trying.
“If Darkside tries to open the wormhole and we don't respond, how long before they reset and try again?"
“Approximately thirty minutes."
If she could just push the ring into an escape orbit, she could buy time. Then estimate when Darkside would try again and blindly time the link ... how to change course without a decent engine.
“Ceevee, if I can spin Betty like a gyroscope at, say, twenty revolutions per second, how much resistance to orbital change does that give us, figuring how bent space will be near the singularity?"
The difference was minimal, but it was there. One of her hijacked linking computers agreed, but still nowhere near enough a change for an escape orbit. “Come on, Betty,” she whispered to the smooth metal. “You can't die. You can not die.” Think. She factored in explosive decompression of the CV's cabin; overheating the battery deck until they exploded and channeling the reaction through a single CV booster; she even added the push of her own body heat. The display showed a hypothetical 21 percent reduction.
“One hour to bridge link-up."
She was well aware of the time. One linkage display read solely the digits 0:59:57.
“Ceevee, can you calculate how much mass on Betty is not absolutely necessary for link-up? Don't include cables. Don't include the computers or anything else that can be moved off the ring."
“Calculating. Your hydration level is low. Please drink."
Tessa drank from the nipple in her helmet, feeling the moisture across her body wick away as the suit recycled.
“Four thousand, eighty-one kilograms."
“And the length of all of Betty's cables, end to end?"
“Seven hundred meters."
Slingshot. Split Betty's mass in two. Half just Betty and half everything else, tethered together by seven hundred meters of cable. An explosive backward burst on the far end would swing Betty into a slightly different course. She saw she could detonate and channel enough force to make it work, if the cables—
The terminal showed a simple figure. The cables would snap.
She doubled them back on themselves. It would be strong enough, but too short; the necessary backward blast was more than she could create. She slammed a palm onto Betty's skin.
“Forty-five minutes to bridge linkup."
“Come on,” she whispered. Ahead of her, the gray sky sat cold and motionless. The blue crosshair blinked gently and fixed.
“Ceevee, since Betty essentially anchors a great space-time wrinkle, is there any way she can be used to anchor the bent space-time around a black hole?"
Ceevee didn't know. She knew it wouldn't. She furiously typed as fast as her gloves would allow, trying to discern if Alice could exert a drag on Betty during linkup—the drag they always fought to minimize—without fully opening the bridge. She tried a shorter version of the pendulum idea, with multiple bursts and higher revolutions building over several minutes.
“Thirty minutes to bridge linkup."
“I know what time it is!” she yelled.
She had two screens of Betty's schematics flitting by in front of her. Looking for anything that could bend space for a few seconds. Alice was the space-bender. Betty just anchored the bridge. She went back to the revolving pendulum idea. If she could eke out some kind of thrust from Betty, or some kind of repulsion, or something more to push Betty slightly, she could make up the difference. She couldn't even help but figure Loránd's kilograms in the back of her head and found some comfort that it wouldn't come close to helping.
Ceevee's announcement of fifteen minutes caught her off-guard. She raised her head from the terminals and tried to take deep breaths. She stared at the soft blue crosshair, trying to calm herself. The steady blue seemed to shimmer, to move.
“Ceevee,” she said, quietly, “remove the singularity crosshairs."
The cross disappeared. For a long moment, nothing happened, then a star seemed to waver, elongate and fade. Another, right beside, shimmered, flickered. The
singularity. Gravitational lensing. Horrifically beautiful. She reached out a hand.
“Presto-mesto."
As she watched, the flickering star slowly stretched into a tiny curve, wrapped into a halo, and faded back as a curve and a point again.
Her breath suddenly misted her faceplate.
“Ceevee! I need to get out of here! I need eight thousand more kilojoules of power from somewhere! Give me something!"
“Please restate query."
Swing the pendulum, perhaps as the bridge begins to open, then shut down connection manually when it exerts drag but before it makes full connection. Detonate everything at opposite tether at the same moment. Throw Betty into—she checked the readout: 0:11:13—a wider arc around the black hole. If it doesn't manage full escape orbit, it might prolong the orbit and instead of transiting back when Darkside attempts a second connection—
“Ten minutes to bridge linkup."
—use the second transit to again produce drag. How to time so many connections? Send a message back somehow during first attempted transit. Coded in the anchoring itself. Decline the anchor in a series—0:07:24—in a series of clicks. It could work, or at least give time to retry as the first orbit decays. She looked up and no longer needed the crosshairs. A series of stars changed color and wavered before their image was stretched. Like flawed glass. Her suit was slick with sweat. She abandoned the pendulum idea. No time to string it together. Working on explosive burst of the CV and batteries. Maybe missed something.
“Five minutes to bridge linkup."
Come on! She could feel it, like an eye, the only motion out there. Open fields and fresh cut grass. Soft summer breezes and grass-stained hands. Think!
“Ceevee—Ceevee, prepare to disengage linkage on my command."
“Linkage disconnect requires commander confirmation."
She pulled pliers from her belt and bent open the terminal housing. Think. Burning the lithium skin and channeling it—
“Sixty seconds to bridge reconnection. Please prepare—"
“Shut up!"
The terminal displays began switching to linkage status. Lights winked on and some of the cables moved slightly as the ring primed itself for the oncoming strain. She tore open the back of the main terminal.
Asimov's SF, February 2006 Page 6