"This is it," Yukariah Heap indicated with two of its arms outstretched, "Mercurand."
Before them, resting on its cradle in the ultra-low gravity, lay a thirty-meter-long gloss-black spacecraft. Except for a few obvious holes and edges, its entire outer hull was smooth and shiny, like the outer anti-laser layer of a fighter's whipple armor. Its nose tapered to a blunt, rounded end, giving the whole craft the general shape of a fudge pop minus the stick. The intake on the front was deceptively small, hardly wider than a docking bay. Jennifer glared at it with a jaundiced eye. "What's that inlet for?"
"The interstellar medium," Yukariah answered.
"Now hold on," Ken objected. "I thought you said this wasn't a fusion scramjet."
"It isn't," the Chairholder said. "Mercurand uses the hydrogen it gathers for dead weight to push against, and for annihilation material with the craft's onboard supply of antihydrogen. In other words, as half your fuel."
"So this is kinda like a RAIR design, then," Ken said.
"Whu?" Jennifer frowned at him.
"RAIR," Ken said, "Ram Augmented Interstellar Rocket. Alan Bond came up with the idea in the early days, before we met the Centaurians. You use a Bussard scoop field during acceleration, but you don't bother using any of the gathered material as fusion fuel. You only use it as reaction mass. This was back before scramjets, when we thought we'd have to slow the incoming material down before we could burn it. The idea never went anywhere, though. Even with a nine-thousand-click-wide scoop field, you'd still only be gathering about 150 grams per second at a hundred permil. With the tiny trickle of incoming prropellant mass, and the losses you incurred by having to mix your exhaust with the propellant stream, the best you could hope for was a 65% improvement in thrust — and that would only happen when you reached a third of the speed of light and were nearly out of fuel anyway."
Jennifer looked sidelong at him. "Is this a hobby of yours?"
"Hm?" Ken asked.
"Vintage starflight technology," she said. "Just how much time do you spend reading up on it?"
Ken rolled his eyes and addressed the Chairholder. "If you're trying to tell me that this is some kind of RAIR design, there's no way that tiny little scoop could send out a collection field anywhere near large enough to do any good."
"It doesn't use the usual magnetic collection field," the Human-Centaurian leader explained.
"What?" Ken yipped. "Then how —"
"There's a long, thin cable stowed inside," Yukariah continued. "Really long. A little towing unit pulls the cable out in front of the spacecraft when it's at speed, then puts a huge negative electric charge across its whole length. Any uncharged particles in the interstellar medium directly in front of the craft get ionized by that scanning ultraviolet laser" — Yukariah pointed its eye stalks at a tiny turret near the nose, nearly hidden inside the hull — "Just like with a scramjet design. Those ions, coupled with the ionized hydrogen already present in the interstellar medium, leave the craft surrounded by protons which are attracted to the cable and electrons which are repelled by it. We got the idea from the little 'fix' that Matloff and Fennely came up with for their charged hull design. The effective collecting radius is enormous, over a hundred thousand kilometers."
"Wow," Ken was genuinely impressed. Then: "Wait, conventional magnetic collection fields have to be specially tuned to avoid Bremsstrahlung drag, since they're influencing charged particles. You can't really tune or shape a plain old electrostatic field produced by a wire. Won't the Bremsstrahlung drag be pretty huge?"
"It's surprisingly small, actually," Yukariah answered, "Not enough to brake the craft significantly."
"So, hold on," Jennifer interrupted. "If this electrostatic 'scoop' of yours had such a huge radius, and doesn't produce any more drag than a magnetic scoop, why does the starship still need antimatter power at all? Why not just put your electric collecting cable on the front of a plain old fusion scramjet and be done with it?"
Yukariah sighed ever-so-slightly. "Mercurand was an . . . aborted design. We didn't know if the towing unit on the front of the cable could be made to work at speed. The towing unit also needed its propellant fed to it from the main hull, which meant a feed line just as long as the cable; the initial construction plan would've had it weighing more than the whole starship. So, we put together the antimatter-powered starship prototype, and the secret antimatter factory, just in case it didn't. The good news is, this design doesn't need anything even resembling a scramjet. The main annihilation reaction can happen at gathering-speed, by just letting the gathered material smack into the antimatter without slowing it down; no need for any of the fancy elongated constriction stages you have in a QC&C scramjet design. And the rather large amount of reaction mass it takes in is continously accelerated until it's right at the Heisenblatt-Sturnbridge ratio, the optimal balance between high Isp and low energy requirements. When it's jetted out the back, the exhaust can be moving at anywhere from a slow thermal crawl to relativistic speeds."
"So, you mean," Ken replied, "The engine on this beast is . . . an antimatter-powered synchrotron?"
"Yes," Yukariah answered. "It's a lightweight, high-efficiency design that uses a QC&C field to recapture all the synchrotron radiation that would otherwise go to waste. In terms of thrust-to-weight ratio, it can sustain 2g until it runs out of fuel."
Torra Zorra took in the size of the spacecraft again with some concern. "Just how much antimatter are we talking about carrying on board here?"
Yukariah sighed. "Fully loaded, Mercurand carries a hundred tonnes of whiteflake antihydrogen."
"Plague's poison!," Jennifer balked. "That's enough to flatten a continent!"
Yukariah tilted slightly backward in the Centaurian equivalent of a shrug. "That's one of the reasons we've had to keep this project secret. If used as a suicide weapon, Mercurand's destructive potential is only an order of magnitude below a Hyper Bomb."
"And that much antimatter's gotta . . ." Torra trailed off, trying to do the mental multiplication. "How much did this fuel supply cost?"
"Nothing, as far as the balance sheets are concerned," the Chairholder answered. "We made all the antimatter here at the HC3 factory, which the government owns. But its market value is . . . well, let's just say it represents about 40% of the resources needed for a Hyper Bomb, and leave it at that."
"I can see why you only built one of them," Jennifer quipped.
"As you speculated, though," Yukariah continued, "The same electrostatic collection cable technology — we call it 'the drogue' — is being installed on several scramjets that're under construction. None of them are finished yet. Mercurand's the only thing we've got that'll fly to another star in less than a lifetime. When the scramjets are complete, if the malcontents still want to leave, they can. Although several of them have expressed a desire not to reveal their destination to us, and don't want us looking over their shoulder after they've gone."
Torra pointed a finger upward in a Centaurian "nod." "So that's why you made this starship small enough to fit through a hyper hole. That way, the malcontents could choose their taking-off point from any system in the Pentagon."
"But for us," Ken punched some numbers into his hand-held data pad, "With a two g ramp-up, even from Sol we'll have to attain 920 permil, or we'll miss the deadline." He furrowed his brow. "Speaking of which, I assume the drogue's collection field can sustain 2g of braking?"
"Barely," the Chairholder acknowledged. "It's the structural load limit."
Ken whistled. "We're going to be cutting it close."
"Braking does replenish the antimatter fuel," Yukariah reassured him, "Albeit slowly. There's a miniature antimatter factory on board. It had to be pretty small to keep the starship's mass low. It can only make about a gram of antihydrogen per second at full output, and that's only when it's getting that energy from the relativistic interstellar medium screaming through it. Down below half the speed of light, you won't be able to recharge even that fast. Your antimatter tanks won't be anywhere near refilled when you reach UV Ceti."
Ken clicked his front teeth. "And how slowly will the onboard factory make antihydrogen when we're parked in orbit around the star?"
"If you're close enough to get a bellyfull of stellar wind in your collector," Yukariah answered, "It might be able to manufacture a quarter of a gram of antimatter per second. But no guarantees."
"So assuming half-empty fuel tanks when we arrive," Ken did the multiplication, "It'd take us six-point-three years to fill them back up again. At a minimum."
"And another ten years to get back," Torra's brain reeled from its gut. "That's over a quarter century for the whole mission."
"Yeah," Yukariah acknowledged somberly, "Half a Centaurian lifetime. I probably won't live to see you return."
"Well," Jennifer shrugged, "At least we won't age in hibernation."
"I will," Torra corrected her.
"Hm?" Jennifer asked.
"Uh," Ken explained for Torra's benefit, "The Centaurians never pursued submetabolic sleep technology. They didn't have to. They automatically hibernate when the temperature gets below . . . what was it?"
"Five Celsius," Torra filled in the gap.
Ken continued, "Right, five degrees. A Centaurian hibernation chamber's little more than a refrigerator. But a hibernating Centaurian still ages, at about one-fifth the normal rate. With the time dilation, the trip over'll take about a year off of Torra's life. If we hibernate for the six-or-more years it'll take for the fuel tanks to refill, that'll be another year or more off the lieutenant's biological clock."
Torra buried its eye stalks in three of its hands. "I wish someone else could go in my place. I really, really wish someone else could go." It sighed, half in resignation and half in anger. "But Arnold requested me, explicitly. Maybe I'm the only one he can use as a typewriter. I don't know."
Jennifer shook her head. "We all knew when we joined that the HCDF would mean personal sacrifices." She straightened up, assuming her role as C.O.. "Then it's settled. We're leaving."
Torra suppressed a nervous twitch.
Jennifer turned to Yukariah Heap. "Chairholder, is there any chance Sirius might let us transit their space in peace, if they knew we were on an interstellar factfinding mission and not a military vessel?"
Gravely, Yukariah made the Centaurian pushing-away gesture that meant "no." "We've made five requests on five different occasions to send a non-military spacecraft through the Sirius hyper hole. Each time, Sirius refused, assuring us that they'd destroy anything we sent through."
Jennifer frowned. "We'll have to do it the hard way, then." She turned back to Ken and Torra. "Both of you, get your affairs in order back home. If we do make it through Sirian space, we're in for a very very long trip."
"The crew here assures me Mercurand will be ready to release in seven hours," Yukariah informed them.
"Then I know where I'll be for the next seven hours," Ken commented, and headed off down the exit tunnel.
Torra Zorra lurched in the same direction, then stopped. Ken might have had money in his account to book a last-minute flight, but Torra didn't. "Can you issue me a boarding pass for a fast liner," it asked Yukariah in Centaurian, "So I can say goodbye to Clan Zorra?"
"Of course," the Chairholder replied, the cadence of its four mouths landing in the mode for deepest solemnity.
It didn't help that about ten Zorrans had gone off to visit Alpha Centauri A-III before the war broke out. Two had been Torra's youthmates — they may have been siblings, Torra couldn't remember. But all ten were stuck there now, prisoners of the impregnable, deadly barricade that every star system had erected against its neighbors, Human-Centauri included.
The rest of Torra's clan, though, lived only half the width of the Habitat Ring away, in the gigantic asteroid officially named Human-Centauri IV and unofficially dubbed "New France." Torra pulled itself arm-over-arm out of sight, on its way to the nearest station-to-station liner, before Yukariah could even ask if the lieutenant wanted an escort.
Torra Zorra could see the old neighborhood as soon as it pulled itself onto the centrifuge's elevator, lit as always by the tiny "suns" ringing the hub. Clan Zorra's homestead was a third of the way around the centrifuge, to spinward. Like most Centaurian homesteads, it occupied a city block of its own, walled in on all four sides for privacy. A translucent tarp covered the entire top of the structure, not to keep out the rain — it never rained in a centrifuge — but to keep out prying eyes from the hub where Torra half-floated now. As the elevator descended, Torra's weight increased, until it was standing in the full simulated 0.5g of its clan's old home on Alpha Centauri B-II.
As Torra wheeled its way around the rim to spinward, it passed the homesteads of other clans. Each walled-off compound had its own unique flavor, its own arrangement of one-way-glass windows and decorations, reflecting the cultural nuances of the clan it contained. Hmmm . . . that was strange. Clan Pooot(l)i(t)i's homestead seemed eerily quiet. Had they moved out since Torra last visited? But ah! This little musing vanished as the meters-wide front gates of the Zorra homestead edged into view. It hadn't changed a bit, Torra thought. A wave of the familiar, the comforting, wafted through its torso. Home!
Torra hadn't told them it'd be coming; there might only be a few clan members at home right now. It'd be a big surprise for any of them, to see the clan's Military Spacecraft Expert after nearly a B-II year's absence. So it came as quite a shock to Torra when the massive front gates opened wide and a throng of Centaurians, packed side-by-side just inside the threshold, shouted with glee as they grabbed it and pulled it inside.
Yukariah's aides must have called ahead, just in case.
Torra was quickly inundated by the attentions and affections of as many of its old clanmates as could press themselves up against it. The lieutenant instantly recognized the mottled skin patterns of youthmates and old guardians alike, and . . . just four meters away from the gate, was that . . . Torra called out the name with two mouths, "Kuur(k)ed(t)di Zoor(r)aa?"
"That's me!" the slender Centaurian replied in the same native language.
Kurkedti Zorra! All the memories came flooding back. Before shipping out for the HCDF, Torra had watched baby Kurkedti being born. Torra had taken its turn, like all the adult clan members, in playing guardian to the infant while it grew, once even mashing grain into an edible paste for it with Torra's own tentacle-fingered hands. On a later extended furlough here, just before the war broke out, Torra had watched the little tyke trying out its baby wheels. Only its own mother could have a stronger bond with it. Torra waded through the familiar, comforting torsos until it reached the now-full-sized clanmate and picked it up fervently. "Kurkedti!" Torra lowered it back down. "The last time I saw you, you could barely even speak out of one mouth!"
"I'm apprentice to A(t)ar(l)o'o now," Kurkedti repiled.
"Atarlo?" Torra half-chuckled. "The builder? That old coot? Its skin was already rock-hard from age the last time I was here!"
Kurkedti only did the Centaurian equivalent of a grin, then quickly dipped all three eye turrets downward, pointing them proudly at itself. "The clan's gonna have another Construction Expert pretty soon."
Torra looked around, expectantly. There! "Mom!" Tratlo Zorra!— The one who'd borne it and fed it grain lovingly mashed by the toil of its own arms! Torra maneuvered through the jubilant crowd to the one Centaurian who had a stronger bond with it than anyone; Tratlo grabbed three of its armpits and hefted it toward the ceiling, as though it were a tiny newborn and mother was offering it a choice ray of daylight. Mother's skin was just a little harder now, just a little less yielding to the touch, than when they'd last parted. Age took its toll on everyone.
"Where's Dasteader?" Torra asked when Tratlo lowered it back to ground level, excited at the prospect of seeing the only youthmate left who wasn't stuck in the Alpha Centauri system.
Tratlo's eye turret rotated slightly, so that no eye was staring directly at its offspring. What was wrong? "Dasteader left the clan," it said solemnly.
"Oh no," Torra's spirits fell.
"Can't really blame it," Tratlo tilted slightly away, "We are kind of big these days."
"Where'd Dasteader go?" Torra asked.
"Clan Rapkesk," Mother replied.
Torra puzzled. "The one in the point-eight-gee centrifuge one tunnel over? Aren't they the clan with the —"
"Human member," Tratlo finished Torra's sentence. "Yes. I think it's a male."
"Whoa," Torra tried to get its mind around such an odd lifestyle. In the HCDF, a Centaurian quickly learned to treat its teammates as a kind of clan-away-from-clan, whether those teammates wheeled on four legs or walked on two; but that was different, that didn't have the familial intimacy, the deep abiding bond of a true clan. Actually having a human in a real Centaurian clan . . . it seemed more like the human custom of keeping a pet. How could such an alien ever feel like an intimate co-equal? The rest of the clan would have to learn that flat, monophonic one-mouthed language of his. He'd be bumping his head on every ceiling and doorway. He'd need his own specially-built toilet, and would probably want those ridiculous privacy curtains. (And humans call Centaurians paranoid!) He couldn't share in any food offerings with them, what with human dietary requirements being downright poisonous to Centaurians and vice-versa. He'd even need a separate dispenser for that foul salt-free water humans drank.
And . . . weren't humans supposed to pair-bond with their mates?
"Dasteader still keeps in touch," Tratlo said. "I get a text from it nearly every day. But don't tell the rest of Clan Rapkesk," it chuckled, "They might get jealous."
A loud "Groooonk!" echoed through the open space of the homestead's interior. Two clanmates had been lucky enough to glimpse the mouth it came from, and wheeled to its source: it was ol' Fichatra's turn to be in heat again. Torra acknowledged the sound at an intellectual level, but was unaffected by it; Fichatra was too closely related, its mating call too similar to Torra's, for either to be attracted to the other. Fichatra might even turn out to be Torra's father, if either of them ever got curious enough to run a DNA test.
"By the way," Torra asked, "When I rolled by the Potliti homestead on the way over, it looked empty. Did they move out?"
Again, Tratlo looked away. "I don't want to talk about it."
Torra wondered, briefly, what might have upset Mother; then its arms stiffened in alarm. It mouthed the word silently: "Plague?"
Tratlo only raised one finger. The Centaurian way of nodding "Yes."
Oh dear. Those diagnosed with the Emotional Plague could be rehabilitated, but they had to go through an often-painful therapy that could take years and even then wasn't guaranteed to work. Torra had a dozen questions, but Tratlo was in no mood. Did just one of the Potlitis get diagnosed with the Plague, or had several, or was the entire clan declared infected? With the war going on, there was no chance for them to return to Alpha Centauri B II, or to go anywhere else that might accept them. Were they making a new home for themselves in the Greeting Area asteroids? Or was the Greeting Area too cramped nowadays, forcing them to find a rock of their own to rework? Did they find another half-gee centrifuge, or were they putting up with a Go'orla-strength 0.8g living environment . . . or were they eking out a living stuck in zero-gee? Did the clan hold together at all? Perhaps they tried to stick by their plague-diagnosed clanmate and found the life unbearable, but couldn't go back again?
That a diagnosis of Plague had the power to break up a clan this way . . . that had never sat well with Tratlo. Torra didn't much like it either.
Fichatra — and whichever mate it had selected this time, it looked to be Ge'et(k)aa — made their way to an alcove that allowed them the room they needed to lock bottom-to-bottom. Torra vaguely remembered what a big deal other people's mating was with humans, and briefly wondered how the human in Clan Rapkesk would react, before ignoring the couple-of-the-moment entirely as all Centaurians were wont to do. In any event, something much more interesting was transpiring in the center of the homestead. Al(r)oyj(f)i, the closest thing the clan had to a Diplomacy Expert, had clambered onto a pedestal and was banging two hollow metal tubes together to get everyone's attention. Alroyjfi was three Earth-months pregnant, its torso bulging below the central hard-cartilage ring. Two more months, and Clan Zorra would have a new little clanmate to take care of. The homestead grew reverently quiet.
"We know you've only got an hour to be with us, Torra," Alroyjfi's seasoned voice boomed in all directions. "And from what they tell us, we may not see you again for over a Jo(a)f(r)iii." It used the classical word, meaning sixteen of the years on their homeworld of Alpha Centauri A-III — about 24 Earth years, or a little under 22 of the years on the clan's more familiar home of Alpha Centauri B-II. Alroyjfi was trying to set the mood. "We can guess you'll be hibernating for much of that time, Torra, but the rest of us, the rest of Clan Zorra, will continue to live our lives in your absence, to grow up and to grow old. Many of us standing here today will not live to see you return."
It paused for effect. "And so, let us make the most of this last hour we have together. Vordlu, Wadch! Bring on the food offerings!"
The cheering shout from the whole clan was almost deafening.
These kinds of food offerings were about as far removed as a Centaurian could get from a normal meal. A holdover from when their ancient ancestors were gatherers, the intent was to provide as many exotic and unheard-of flavors of Centaurian "plant" life as possible. A familiar flavor at one of these rituals was as anathema as a human knowing what he was getting for Christmas. Huge Centaurian industries existed for the sole purpose of breeding new food plant varieties to satisfy the voracious public need for more and more food offering flavors and textures.
Food offerings also played a prominent role in clan-changing rituals, with all the emotional baggage that entailed.
Vordlu and Wadch, the clan's Gathering Experts — which nowadays meant little more than grocery shoppers — burst forth from the kitchen pushing carts loaded with mutlicolored goodies. The colors were unnaturally bright; they had to be, for a Centaurian's muted color vision to notice. It was a beautiful spread, begging to be tasted; a feast worthy of any great occasion. How long ago had they found out Torra was coming? It couldn't have been more than an hour-and-a-half ago. The two Gathering Experts had done a remarkable job for such a short lead time.
Yet another reason Torra loved its clan.
One by one, each clanmate grabbed a bowl from a cart as it passed, and filled it with the ingredients that looked the least recognizable. Eye stalks craned in groups of three to get the best possible look at the grainlike and lichenlike cornucopia in their hands in front of them. Aside from the vague grunts of Fichatra and Getka in the distance, which soon abated as the two finished, the whole compound grew quiet — so quiet Torra could hear the gentle breeze from the centrifuge's air pumps as it ruffled the tarp roof. Then, at an unspoken signal, every Zorra dug in voraciously to the bowl before it with hands and mouths crunching and smacking.
The flavors were every bit as alien and sumptuous as they looked. The bright red grain tasted like the lichen-like baaai(t)i; had one of the latter's flavor genes been spliced into its genome? The plain grain, which looked so deceptively like their oood(v)(r)uut(l) staple, surprised them yet again with a punch to the palate from out of nowhere. One handful contained pebbles disguised as edibles, which would have chipped a human's tooth had a human partaken of them by mistake — not that any human would want to try foodstuffs based on Centaurian levulorotary sugars. The whole meal was as wonderful a food offering as Torra had ever partaken of.
Or maybe that was just the bittersweetness of this last big goodbye.
Torra Zorra pulled itself through the entryway to the starship deck on which Mercurand stood, its melancholy glaringly obvious to the other Centaurians it passed — though a human eye could hardly detect its expression. Jennifer Doe and Ken Tractor were already there, having tied up whatever loose ends they'd had dangling homeside. The deck looked much more cramped than when Torra had last been here; makeshift walls that stretched to the ceiling now surrounded Mercurand on all sides, shiny with new stainless steel. Only the occasional tiny window interrupted the upright planes of burnished steel to give a view into the spacecraft's berth. Windows, and one open doorway for the last of the loading and pre-flight checks. Torra peeked through one of the windows, and saw that the airtight dome roof over Mercurand's head was still sealed shut; the experimental antimatter-fuelled starship wasn't yet in vacuo, but they doubtlessly intended to launch directly from here.
The whole wall assembly looked hastily cobbled together. They hadn't planned on launching Mercurand this soon.
"Ah, there you are," Ken said, pulling himself over to Torra by using the hand-and-footholds on the floor. "Ready for our exile?"
"Yeah," Torra answered, resigned. "Damn it, it's like losing my whole clan at once. You're a . . . male, right?"
"So you were probably saying goodbye to your girl. That's what you male humans usually have, isn't it?"
"I was on furlough with her when the Chairholder's call came in," Ken replied. "We'd already said our goodbyes." A pained look crossed his eyes, which Torra's regular interactions with humans had taught it to notice. "No, I used these last hours to visit Jake. He's an old buddy of mine. They diagnosed him with the Plague two years ago; he's been living with the other outcasts in the Greeting Area ever since. He didn't want to go through rehab for . . . believe it or not, moral reasons." He looked Torra Zorra squarely in the eye that was pointing at him. "Jake likes Human-Centauri. He just doesn't believe the Emotional Plague is a real thing."
Torra's brain-gut reeled. Were such a-Plaguists among those malcontents who wanted to found a new Human-Centauri?, it wondered.
"C'mon," Ken urged it, "Let's do a walk-around."
The mismatched pair pulled themselves to the door in the makeshift wall via the hand-and-footholds on the floor. The tall ceiling was somewhat intimidating; push off too hard, and you might be stuck in midair for a minute or two before this ultra-low gravity pulled you back. Inside the walls, Mercurand lay moored in place with clamps set into the floor beneath it. Torra pulled itself up next to the starship's right side to get a close look at the outer hull. The articulations between the whipple plates were slender but numerous; from what little could be seen between in those tight gaps, Torra estimated this outer layer of armor to be a uniform half-centimeter thick.
"How many layers of whipple armor does it have?" Torra asked.
Ken whipped out a data display pad onto which he'd loaded the spacecraft's blueprints and schematics. "Looks like . . . uh, one."
"Only one layer of armor?" the Centaurian worried.
"Well, one whipple layer, anyway," Ken answered. "Looks like the main hull underneath is also covered with about a centimeter of hard steel; but that inner coating's part of the hull. There's no vacuum gap underneath it."
Torra felt uncomfortable. Deployer armor this wasn't. If they were going to cross Sirian space, getting shot at by fighters or even Gate Guards, they'd better have more than just this little bit of meteor shielding — or one lucky grazing shot or shrapnel burst would leave them helpless.
"I'm actually surprised they put on that much armor," Ken mused. "The design's obviously optimized for weight savings, not combat. Although . . . some of the design decisions are kinda quirky."
"Let me see," Torra asked, reaching for Ken's pad.
"You'd better copy this data onto your own pad," Ken commented, handing it over.
Torra grunted; it didn't need to hear the obvious, there just hadn't been an opportunity yet. It took its own pad out from the regulation HCDF equipment sash all Centaurians had to wear — how clumsy and burdensome clothing always seemed, 'til you added pockets — and plugged a data cable into both of them with a third hand. A few taps on Ken's screen with Centaurian tentacle-fingers, and data transfer commenced. Torra skimmed the blueprints while the copying finished. Remarkably, the builders managed to cram an Ascender into this hull, albeit a tiny one with barely enough room for a single passenger. Scanning Mercurand's blueprints further, a long, narrow tube caught Torra's eye.
"Is that —" Torra began, then pulled itself along the floor with its two free hands until it reached the flank of the starship. Dead center on the near side, a small circular opening was covered by a hatch that had been swung open for inspection. The smooth metal rails lining the open hole, leading ever-deeper inside, were unmistakable.
"That's a slug launcher!" Torra concluded.
"Huh!" Ken raised his eyebrows, then pulled himself over to Torra for a better look. "I didn't realize we were armed."
Torra unplugged Ken's pad and handed it back, while one of its two free hands worked its own pad's onscreen browsing controls. "Yep. A garden-variety E-43 mass driver. Looks like the magazine holds about forty rounds."
"So if we get chased by an enemy fighter, then," Ken said, "We can shoot at it 40 times before we're empty."
"Twenty times," Torra corrected him. "Half these rounds are shrapnel packs, designed to break apart when they leave the muzzle. They're for point defense against missiles; they don't stand a prayer of punching through whipple armor."
Ken worried. "If the slug launcher can be used for point defense, does that mean we don't have any other point defense weapons?"
Torra was thinking the same thing, scanning the blueprints over and over. "No," it sighed. "No particle beams, no low-mass slug guns, not even any anti-missile lasers. Other than a couple of chaff ejectors, the slug launcher is the only system capable of throwing things."
"And it's pointing sideways?" Ken asked.
"Of course," Torra stated matter-of-factly.
"But why? If it were on the front, we could counter the recoil with engine thrust."
Torra eyed the male human as though looking down on an ignorant child. "When are we going to be shooting?" it asked rhetorically.
"When . . . somebody's chasing us?" Ken wondered what the Ceutaurian weapons officer was getting at.
"And what will we be doing when they're chasing us?" Torra offered.
Ken threw his head up, the lights finally going on. He wondered how he could have missed it. "Evasive maneuvering!"
"Right," Torra replied. "A deployer's so long from nose to engine that it's more efficient to thrust sideways during evasives than it is to rotate, but this spacecraft is barely 30 meters long. It doesn't need the kind of powerful attitude thrusters that are on a deployer to make it rotate. During an evasive, we'd point the engine perpendicular to the enemy at all times, so that our position on its targeting sphere moves around the most. That means any weapons we want to fire in the target's direction, including point-defense weapons, have to fire sideways. Yes, the recoil from a slug launch will knock us a little off course, but we can always correct our course after the fighting's over."
"So we'd take the full, uncountered rec. . ." Ken's voice trailed off. He stared intently at his data display pad, tapping the page-navigation controls until he stopped on the fuel storage specs. "Hmm," he said flatly, frowning. "I can't tell from this how hard a jolt we can take. I mean, how hard the antimatter fuel can be jostled around."
Torra drew breath sharply. Cascade containment failure. The absolute worst thing that could happen to you while carrying antimatter. "The Chairholder said we're using a hundred tonnes of 'whiteflake antihydrogen.' What does that mean?"
"It means," Ken grumbled, "That we're not using magnetic containment. We cool the antihydrogen down to a few millionths of a degree above absolute zero, where it condenses into a kind of snow. We put a net positive electric charge on the inside of the fuel tank's walls, which is enough to keep the valence positrons away from the valence electrons in the container. There's also an octupole magnetic field that helps contain the snow, but not by much. At such a low temperature, the fuel can even touch the walls without annihilating. Provided, that is, that it doesn't bang into the walls too hard."
"So you want to know what 'too hard' is," Torra replied.
"And whether firing the slug launcher would be enough to put us at risk," Ken noted.
Torra tilted slightly away in a Centaurian shrug. "They wouldn't build an E-43 into the hull if the kick was more than the spacecraft could take."
"This is a prototype, remember?" Ken cautioned. "The guys installing the weaponry might have only looked at the structural stresses, not the fuel containment limits."
Torra suddenly felt very uncomfortable.
"I'm going to ask one of the fuel engineers," Ken said, and made his way out of the makeshift docking bay.
With Ken gone, Torra pulled itself over to Mercurand's intake and peeked in. The bulbous, bell-backed lump clipped just inside must be the drogue's towing unit. It would keep the long, long attractor cable taut while their main engine thrust them ever-forward through the void. Torra tried to see the cable attached to the back, but at that depth the shadows were too deep and the cable too thin. The specs would be on the data pad, though. Torra paged through the blueprints until . . . could that be right? The cable diameter was listed as 3 x 10-5 m. (Curse the human penchant for powers of ten! Torra always had to mentally convert their numbers to base sixteen, just to get a handle on them.) That worked out to less than a thirtieth of a millimeter. That wasn't a cable, that was hardly even a wire; it was the width of a hair on a human's head. And . . . oh my, Yukariah wasn't kidding about it being really long. It would stretch nearly a hundred thousand kilometers when fully unreeled.
Was the reeling mechanism robust enough to keep this metal thread from getting tangled?
With another eye, Torra glimpsed its C.O. pulling herself in through the makeshift bay door. She had to glance around before noticing the Centaurian. "Oh, there you are."
"Ma'am," Torra saluted with the arm closest to her, still holding the data pad up to an eye with the arm on the opposite side.
Jennifer pointed a thumb toward the bay door. "What's our Navigator doing out there?"
Torra answered, "He's gone to find out how big the danger is of blowing ourselves up."
Jennifer rolled her eyes. "Ho boy. That's . . . a risk I prefer not to dwell on. I figure we either make it, or we don't. But there's something else that's been bugging me about this antimatter engine. We'll be sucking in hydrogen ions from the local fluff, i.e. protons, but because we're using electostatics to do it we won't be sucking in any free electrons to match. We're carrying antihydrogen in our fuel tank, which is antiprotons and positrons. After the antiprotons annihilate with the scooped-up protons, we're still gonna have positrons left over, with nothing to annihilate them with. What is it, exactly, that the starship does with them?"
The question piqued Torra's curiousity too, and the Centaurian began tapping on its display pad again, searching through Mercurand's data. It zoomed in on the annihilation reactor details, its QC&C recapture field, the charge separators, the routing conduit . . .
"Whoa," Torra exclaimed. "Am I reading this right?"
Jennifer craned her head over the hump of Torra's torso. The Centaurian held the pad so that she could see the display, and traced the routing conduit with a tentacle-finger. "Oh, geez," she said with some alarm, "I think so. The positrons get dumped directly into the exhaust unburned."
Torra paged through Mercurand's notes some more. "Fortunately, it looks like that's only done with the scooped protons. When we're burning our own internal hydrogen supply, we'll have electrons to annihilate the positrons with."
Jennifer nodded. "So at least while we're still in-system, we won't have to worry about blasting other space traffic with antimatter." She shrugged. "Still, that's an awful lot of antimatter going to waste. Burning a hundred tonnes of antihydrogen means we'd be venting, what, fifty kilos of positrons?"
Fifty kilograms of antimatter! Torra tried to wrap its mind around this figure. Annihilated with 50 kilos of normal matter, that much antimatter would produce two-and-a-half trillion kilowatt-hours of energy, or a two gigaton explosion. It represented a fifth of the positrons needed for a full-blown hyper bomb. And they were going to be venting it out their tailpipe as an acceptible loss that they could afford to waste. Such was the terrifying magnitude of their fuel supply.
Ken returned through the makeshift room's only door. "Colonel," he saluted instinctively.
Jennifer returned the salute, holding Ken's eye. "Captain."
"Well, Lieutenant," he turned to the Centaurian, "The cryo tech I talked to claims the frozen antihydrogen will withstand a sustained four gee, or a quick jolt of up to forty gee. Past that, there's a danger of rapid enough wall-annihilation for cascade failure."
Torra closed its other two eyes and focused on its data pad, bringing up the specs for the slug launcher once again. "The E-43's shock absorbers should be able to spread the launch forces out over a tenth of a second, which'll reduce the jolt on the rest of Mercurand to a little over 20g — if we're carrying a full fuel load. If our fuel tank is empty, though, that cuts our mass in half, which means a slug launch'll impart a hair over a 40g jolt to Mercurand."
"So no shooting while the fuel tank is empty," Jennifer said. "Which it should only be when we're at top speed way deep in interstellar space."
"With nothing to shoot at," Torra completed the thought. "But that assumes that the launcher's shock absorbers do their thing without a hitch. If one of them jams, or gets even a little bit sluggish . . ."
Jennifer shrugged. "Shock absorbers have internal diagnostic sensors, don't they? The S.I. should spot any off-kilter reading before it becomes a threat."
A Centaurian stranger approached. Neither Ken nor Jennifer could tell if it was military or civilian, since it wore no clothing. "Colonel Doe?" it asked hesitantly, "I'm Jibtio Turlkrayr, from Logistics. I need you to okay the onboard supplies list. It's the final cut for your mission, and most of it's already been stowed on board Mercurand, but . . . well . . . it's you and your crew who're going to have to live with these supplies, not us here in the hangar."
Jennifer sighed, plugged Jibtio's data pad into her own, and scanned the downloaded contents. The food selection seemed awfully monotonous. "You don't have any human meal planners in your group, do you." It was a statement, not a question.
"No," the Centaurian turned its eye turret so that no eye was pointing at her. Jennifer guessed that this was a gesture of shame.
"You'd better take me to the rest of your team, then. Your 'menu' desperately needs a human's touch." Jibtio began brachiating back toward the door without another word. She started to follow the Centaurian out of the docking bay, and as she pulled herself along the handholds she craned her head over her shoulder to look at Ken. "This shouldn't take too long."
Ken watched her vanish out the door. There was a look in his eyes that Torra couldn't quite place. He turned to the Lieutenant, and asked, "Did you notice —" he caught himself. "No, no, of course you wouldn't, you'd need a nose. Sorry. The Colonel . . . she's wearing perfume."
Torra tried to remember. "Perfume makes humans smell good to each other, right?"
"Then . . . she's doing it to help the two of you get along better?"
"M . . . maybe." His face reddened a bit, but not enough for a Centaurian to notice. "Come on," he changed the subject, "Let's take a look at the interior."
There was no obvious entry hatch on the starship. The only way in or out was, apparently, though the docking bay for the Ascender. It made sense; the bay was one big airlock, with enough wiggle room for the Ascender to fit through the outer door without scraping. Torra and Ken both reached up, grabbed the doorway rim, and pulled themselves up-and-in in the low gravity. Inside, clear "thrust floor" and "braking floor" labels pointed toward the engine and nose of the starship, respectively, and a few handholds peppered each of the five walls. The Ascender itself, a tiny cone, still managed to dominate the room. Its engine bell barely stretched the width of a torso; Ken commented, "I'm amazed they can make a hot-fusion engine that small."
Torra tilted slightly away in a Centaurian shrug. "The ones on missiles are even smaller."
The two made their way toward the inner docklock door and stepped through to the spacecraft's proper innards. Inside, warning labels and emergency equipment glared at them along every half-meter of the short hallway. There was the sense that any wrong move would spell instant doom, even moreso than on a Deployer. The builders never wanted you to forget how hostile and utterly unforgiving the environment would be when this spacecraft was at speed between the stars. Vacuum, heat management, and life support, the three main worries of any spacecraft not at war, were of only secondary concern in Mercurand. The greater danger was the interstellar medium at 920 permil. Should the forward sweeping laser or the electrostatic scoop fail while they were at speed between the stars, even for a second, a cosmic ray bath would sweep through the starship and fry every electronic and living thing aboard.
Of course, they'd have to survive an even deadlier gauntlet to get that far in the first place.
They rounded a tight corner and came to the command center. It was the second most spacious room in the spacecraft; in other words, cramped. A surround station had been installed for Torra, with human-shaped consoles for navigation and command. The deep, strap-heavy seatcouches so prominent in a deployer's command center were notably absent; Mercurand's side maneuvering thrusters were too weak to toss the crew about. Like a deployer, though, the command center had been built with a definite sense of down toward the thrust floor — currently the back wall in the asteroid's low gravity. The two human consoles, the Centaurian surround station, the cabinets, the labels . . . everything was oriented with the expectation that heads and eye stalks would be toward Mercurand's nose, and feet would be firmly on the floor toward the engine. Hopefully, they wouldn't have to use this room during the interstellar braking phase, when "down" was pointed toward the nose.
The displays and indicator lights at the panels were all on, and looked to be functional. That meant the ground crew had already gone through the power-up procedures, probably saving them a good hour or two. Ken turned to his meter-and-a-third tall comrade and asked, "Since Mercurand appears to be up-and-running electronically, shall we meet the fourth member of the crew?"
Torra raised a tentacle finger in a Centaurian "nod."
"S.I.?" Ken moved his gaze from one display panel to the next.
"I'm listening," came a neutral, masculine voice from two wall speakers.
"Hi, I'm Captain Ken Tractor, Navigator." He indicated the Centaurian. "This is Lieutenant Torra Zorra, weapons officer and, from what they tell me, the reason for our mission. Do you know what our mission entails?"
"Yes," the voice replied, "All available data were given to me by the power-up crew. We are to transit the Sirius system, embark from Sol on a powered interstellar trajectory for the Luyten 726-8 system, and investigate UV Ceti IV. I am running simulations of possible scenarios in Sirius and Sol space now. The only scenario I've found that has good odds of success requires both Sirius and Sol to allow Mercurand passage through their space without attacking it."
"Which is probably not going to happen," Ken said somberly.
Torra Zorra twitched. It said, its voice flatter than ever, "I'm going to need more reassurance than this."
Ken sighed. "I don't know that I can give you that. As slim as our chances of survival are, we can only beat those odds if we make a realistic assessment of our —"
"I'm Centaurian," Torra hissed. "You gangly bipeds might think it's 'noble' to sacrifice your life for others, but we don't."
"Huh?" This was at odds with what Ken had learned. "But there are plenty of historical Centaurian heroes who risked their lives."
"Risking death for the good of your clan is heroic," Torra countered. "Ensuring your own death isn't, whether it's for the good of your clan or not. Are you familiar with the legend of Clan Hr(k)iib(l)oo?"
Ken shook his head.
"Hrkiblo was a 12-member clan, part of the West Alliance back in the days of the North Go'orla war. The whole clan was holed up in a concrete basement, taking shelter from falling bombs. From the intensity of the air raid, they figured there wasn't a Confederate soldier around for kilometers. They were wrong. A commando locked their exit door, then rolled a heavy fragmentation bomb right in through the basement window. The bomb sat there in the middle of the floor, counting down the few remaining seconds to detonation. There was no way to defuse it, and it was too heavy to lift back up to the window in time. All they could do was cower in the corners of the room and hope their injuries wouldn't be fatal."
Torra lowered its voice, almost reverently. "Any one of those twelve clanmates could have thrown its body over the bomb and saved the others. They all knew it. They all wanted, desperately, to save each other. But they didn't. The bomb went off, they all died, and Clan Hrkiblo was no more."
"That's terrible!" Ken blurted.
Torra spoke deliberately. "They're. Folk. Heroes. I only hope that if Clan Zorra faces a threat like that, I'll have the courage not to sacrifice myself to save them."
Ken swallowed uncomfortably.
"Do you understand now?" Torra went on. "If my chances of survival are nil, or near it, my clan will find out eventually, and I'll be branded 'reckless.' If I die, I'll be infamous, an example for the children of what not to do. Even if I live, Clan Zorra would probably disposess me. I'd be clanless!"
"I'm sorry," Ken said. "But . . . even if the mission details are kept totally secret? We could lie to your clan, tell 'em that Sirius and Sol agreed to let us through."
"Whatever happens on this mission, its details will eventually be declassified. You know that."
"Well . . ." Ken searched for an answer, "Well, it's not like you're volunteering to go. The top brass ordered you to!" He brightened. "You're not reckless, you were kidnapped."
Torra spoke in an intense whisper, twitching even harder. "I need to know this mission is survivable too. For me. Or I won't be able to fight my own instincts."
"All right," Ken put a hand to his face. "I've been going over our options myself. I don't have any intention of dying either. We know Sirius won't let us through without trying to kill us, but we don't know about Sol. If we don't tell 'em we're packed to the gills with antimatter, they just might be sympathetic to our mission. As far as getting through Sirian space, well . . . Human-Centauri has never made an incursion through the HC/Sirius hyper hole since the war began, and most likely, they don't expect us to. They're doubtlessly a lot more worried about Sol than they are about us. I know for a fact they don't have a full-blown Second Guard station at the Sirius/HC hyper hole, like the two they have at their Sol hyper hole; they only have a few fighters stationed at the Second Guard points, fewer even than we do at our Second Guard points. And their deployer crews are almost certainly out of practice."
Torra's twitching diminished, but it still wasn't calm enough yet to lock its musculature in repose. "Think we might be able to wriggle past the Sirius/HC Gate Guard, if we make transit fast enough?"
Ken smirked. "We just might."
Torra heard the swishes and clunks of somebody clambering around nearby, but having only one ear, there was no way for it to discern the direction the sound came from. Ken, on the other hand, turned immediately to face the entry corridor.
"I thought I heard you in here," Colonel Doe said as she pulled herself through the Command Center's entry hatch.
"Colonel," Ken saluted, and Torra did the same with the arm closest to her.
"Well, Captain, you'll be happy to know we have some last-minute provisions being swapped aboard, chosen by a human mess officer. Breakfasts are actually going to feel like breakfast instead of last week's lunch."
Torra snorted through a mouth facing away from them. Three meals a day. Humans were voracious. How Earth's ecosystem had managed to feed billions of them without collapsing, it could only guess. And there were so few of their own native plants they could digest! Maybe that was why they were willing to turn to (ugh!) animal sources for some of their food.
A hollow, metallic clunk echoed through the hallways. Then another. "That sounds like it's coming from outside," Ken commented.
"Yep," Jennifer said. "They're giving us one last piece of ordnance. A message missile."
Torra puzzled. "I don't remember seeing a missile launch tube on the hull, or in the schematics. Not even a little message-missile-only tube."
"There aren't any," Jennifer confirmed, "They're mounting it on a hardpoint on the outer armor. It's carrying a recording of the Chairholder explaining our mission. Once we're through the HC/Sirius hyper hole and clear of their Gate Guard and Second Guards, we'll launch the missile toward the Sirius/Sol hyper hole. If it makes it that far, it'll transmit the instant it makes transit, or sooner if Sol's Gate Guard or Second Guard gets within line of sight. Either Sol will play nice and let us leave their system in peace, or they'll blast us to flinders since they'll know we're coming."
"Oh," she continued, "And on the off chance that Sirius will let us through without a fight, we'll be broadcasting the Chairholder's message to all the Sirian listening stations too. And . . ." her mouth tightened for just a moment, "There's one other general order we've been given."
Ken furrowed his brow attentively. Torra couldn't read her facial expression, but "general" orders were never good.
She sighed. "It's bad enough that this will be the first time Human-Centauri has made an incursion into enemy space. That alone could provoke Sirius — and CN Leonis, when they hear about it — into stepping up their attacks against us. But if they find out we're carrying any antimatter at all, let alone a hundred tonnes of it, it won't matter what our actual mission is. Both systems will almost certainly decide we're a much bigger threat than they've been giving us credit for. Especially CN Leonis, since they're run by, um —" she glanced at Torra somewhat self-consciously, "Centaurians."
Torra knew what she meant, and she was right. Centaurian paranoia, while par for the course among themselves, was far stronger than its human equivalent. You didn't become the dominant herbivore on your planet by letting potential predators run around unopposed until it was too late.
"Therefore," she went on, "If we can't avoid being captured, we're to detonate all remaining antimatter on board, in a manner that directs the gamma rays away from our would-be captors. If we're lucky, it'll look like an ordinary fusion explosion."
One of Torra's eyes glared at her. "I didn't see any emergency cutout in Mercurand's side that would allow the containment tank to be jettisoned."
"There isn't one," Jennifer answered somberly. "And it wouldn't matter if there was. In order to 'detonate' a hundred tonnes of antihydrogen, we've got to annihilate it with a hundred tonnes of normal matter. We start out carrying a hundred tonnes of normal hydrogen for run-up fuel, but we have to use it for both annihilation material and propellant, which means we use up a hundred grams of it for every gram of antihydrogen we burn. The containment tank only masses a tonne by itself. The only place we can get the rest of the annihilation material we'll need is . . . Mercurand itself."
Ken glanced at Torra, keenly aware of the discussion they'd just had. "Self destruction with zero chance of survival."
"Yeah," Jennifer sighed. "We can't all fit aboard the Ascender, and even if we could, the situation might not give us time to abandon Mercurand."
A tiny twinkle graced Ken's eyes. "Well then, we'll just have to make sure they don't get the opportunity."
The three exchanged glances wordlessly. They were all HCDF officers, and no strangers to the risk of death. Here in a tiny starship built around a bomb, or in their past duties sequestered in the heart of a Deployer, the best they could hope for when under attack was a lucky roll of the dice.
Jennifer clicked her teeth. "The ground crew's going to make one final inspection of the interior, to make absolutely sure that everything that's supposed to be here is here. Then, it's go time. What say we take one more stroll around the deck . . . you know, just to get our last taste of home for the next two decades."
The next twenty-five minutes passed for Torra as a surreal blur of quiet contemplation and strangeness. Torra had never been present at a dirtside launch before, let alone at the launch of a classified spacecraft. The final activity around and inside the hull proceeded in long, slow milling punctuated by brief flurries over the little details or omissions that no designer could possibly have hoped to account for. The whole cavalcade seemed an alien dance that he could only watch in bewilderment, never fully comprehend.
When they'd pulled themselves back inside after the final salutes and handshakes, and cleared the inner door to the docklock, Ken twisted the actuator to its "closed" position and the door slid shut. The clank as the airtight seal engaged at last woke Torra from its reverie. This was it. They'd shut out the rest of the universe, and now this sealed interior was their whole world.
They made their way back to the command center and assumed their stations with the businesslike precision their years of Deployer service had drilled into them. Jennifer switched on her external camera suite, showing bare walls, a floor hidden in darkness, a brightly-lit roof, and the last of the ground crew brachiating their way toward the makeshift launch bay's only exit. She took out a small data card. "Since this spacecraft is a black project, the Chairholder's office insisted that all comm traffic be encrypted, even when it's with our ground controllers just fifty meters away." She slipped the card in a reader slot, glanced at the public and private keys, then switched it into the comm circuits and keyed her mike: "Ground, this is Mercurand. Radio check."
"Mercurand, you're loud and clear," the call came back in their speakers.
"Ground, you're loud and clear too." She released her transmit key. "S.I.?"
The speakers intoned: "I'm listening."
"Go through the pre-launch checklist," she instructed.
"Proceeding . . ." One by one, the voice rattled off the automatic systems that checked out — from the air circulation fans to the cryocooler in the antihydrogen tank — then asked the tiny crew to check each manual switch and lever in order. When Ken replied with the final "Check," the speakers at last declared: "S.I. internal diagnostic . . . all subsystems nominal. Pre-launch checklist complete."
"All right, Ken," Jennifer nodded to her Navigator, "Time to get us off battery power. Start charging the capacitor for first QC&C field start."
"Aye, Colonel," he replied, then flicked a button. "Charging. You know, it's kinda weird to hear that order again. This beast doesn't even have a QC&C engine, and here we are, having to start two separate QC&C stages just to get the APU up and running. Let alone the recapture field for the synchrotron."
Jennifer smirked. "Hell, even fighter APUs use QC&C fusion."
"Sure, but not two-stage fusion," Ken shook his head.
"Fighters have a deuterium tank," Jennifer rolled her eyes. "We don't."
"Yeah, yeah, okay," Ken half-sighed, "We have to start the proton-proton stage so we can use it to recharge the capacitor to start the deuteron-deuteron stage. I'd expect that for the scramjet engine on a conventional starship, but it just feels so . . . odd, doing that much for a plain old APU."
A light went green on Ken's panel. "Capacitor charge level's ready. Proton-protium APU stage field start!" He pressed the programmable switch, and several million Watts surged from Mercurand's one-and-only battle capacitor into the APU's first stage QC&C initiators. It was over faster than an eyeblink; the Quantum Confinement-and-Constriction field, so power-hungry to start, now hummed almost imperceptibly with near perfect self-sustaining efficiency. "QC&C cell grid is green," Ken read his status display, then: "Starting fuel feed." A faint, crackling hiss wafted from the same area of the starship as protons fused into deuterons. Positrons also resulted from their unions, but these quickly merged with available electrons to yield gamma rays, which were in turn absorbed by the QC&C field and transformed directly into electric energy. The cabin lights in the command center brightened a tiny bit as the new electric source took the load off the batteries. A few seconds later, a whispered whir heralded the bladeless turbine, spinning with the force of the fusion exhaust's heat — something no QC&C field could harness. "Turbine is nominal and producing power," Ken reported, "No blockage. Pre-turbine exhaust velocity is 21 permil. Charging capacitor for deuteron stage field start."
The whole process repeated for the smaller, but more important, second stage. Now, instead of gushing deuterium out its exhaust vents, the APU disgorged helium — which hit the turbine at five-and-a-half times the prior exhaust velocity and thirty times the energy. The intimidating electrical output of the whirring dynamo charged the capacitor at a rate the batteries could never hope to approach, to its highest voltage level yet.
"Capacitor's charged," Ken noted. "Ready for recapture field start."
"Do it," Jennifer ordered.
Ken flipped the soft switch, and this time, the capacitor delivered nearly a billion Watts to the much larger QC&C initiators belonging to the main engine. In less than a heartbeat, the recapture field sprang into being, lining the inner walls of the synchrotron. This was no grid of nanoscale cells for squeezing pairs of nuclei; although it used the same basic QC&C technology as the APU, and would in fact act as confinement against any misbehaving particle, it's main purpose was far different. The engine accelerated electrically-charged particles in a circle, driving them faster and faster until they reached the optimum velocity for spacecraft exhaust. But accelerating charged particles always meant radiation, photons, energy robbed from the particles' speed. The recapture field existed to plug up that loss; each stray photon that hit the field would turn completely into useful electric energy that could be pumped right back into the particle-accelerator. "Engine QC&C is green and routing," Ken read his display, "Next capacitor recharge is already underway."
Jennifer keyed her mike again. "Ground, this is Mercurand. We're ready to leave. Open up the roof."
The same voice as before came back: "Mercurand, acknowledged. Evacuating the launch bay in preparation for door retraction."
After a few seconds, Ken confirmed, "It's depressurizing out there, ma'am. External pressure's down to 40 kPa and falling." He looked up. "And no hull leaks."
Jennifer snorted. "If something that basic went wrong with this prototype, I'd scrub the mission."
The air that had once swaddled their outer hull continued its exodus. Torra brought the gauge up on its own display, noticing the gentle whir of the internal air circulation fans that much more acutely. If there was a problem at this stage, the ground crew would repressurize the bay long before the three of them were in any danger, but still . . .
"Mercurand," the speakers blurted the ground controller's voice once again, "Bay pressure is down to vacuum nominal. Retracting airlock doors."
Jennifer switched her big display to hull camera 3, the camera that faced upward while the spacecraft was gravity-docked. The blue-white lights of the bay dazzled off the exposed metal of the roof doors, plain flat surfaces with an almost imperceptible interlocking seam running right down the center between them. Silently, a jet-black line appeared through the middle of that seam, and slowly widened as the twin doors crawled apart. There were stars hiding in that black gulf beyond, far too dim to see against the doors' glare. But as the doors retracted out of the camera's frame and the camera automatically cranked up its exposure gain in the relative darkness, the stars came alive. Sirius, their first destination, shone almost directly overhead, nestled comfortably in the corner of Eridanus — or at least the portion of Eridanus that lay more-or-less intact in Human-Centauri's sky. Sol, their second destination, was somewhere below the horizon next to Altair. Of course, their ultimate destination — UV Ceti — would be too dim to see without magnification until they were practically on top of it. If they made it that far.
The ground controller's voice intruded again: "Mercurand, airlock doors are fully retracted. Handing you over to departure control." There was a brief pause, then a new voice sounded over the speakers: "Mercurand, this is your special comm attaché. It's our job to insert you into HC3's normal space traffic while keeping your spacecraft design classified. They'll know your launching point, that you're government, and that your mission involves the HC/Sirius hyper hole; but that's it. Colonel Doe, as the mission commander, we'll need to know your flight plan."
Jennifer grunted, then keyed her mike: "Comm, this is Mercurand, stand by. We're . . . kinda winging our flight plan. We'll have concrete details for you momentarily."
"I recommend we make transit at speed," Ken said flatly. "It'll give their Gate Guard less time to—"
"Agreed," Jennifer cut him off. "Which side of the hyper hole should we transit through?"
Ken brought up an orbital plot of the Sirius A system. Two short lines, labelled "Sirius/HC" and "Sirius/Sol," represented the current positions of the two hyper holes relative to one another. Red and green arrows perpendicular to the Sirius/HC line marked the current exit paths for the peacetime arrival and departure sides of the hole. Ken could've run a computer derivation of the optimal course, but the positions shown made their choice all too obvious. "We need to go through the Arrival side of our hyper hole," he declared. "For the next week or so, the Departure side at the Sirius end will be pointed almost directly toward the Sirius/Sol hyper hole. If we're going in at speed, perpendicular to where the hole's surface will be pointed when we get there, we'll have a nice speedy head start in the direction we already need to be going. We'll also be headed away from Sirius A IV's current location, so they're less likely to see us as a major threat."
"All right, then," she decided, "Plot a flight plan that'll line us up with where the Arrival side'll be after accelerating at a one gee for four-and-a-half million klicks."
"Only four point five million kilometers?" Ken puzzled. "If we're going in at speed, we'll need a longer runway."
"We're only going in at one permil," Jennifer replied.
Torra twitched. In simulated drills, it had shot at targets moving upward of fifteen permil relative, and occasionally even scored kills. True, it had been prepared, and had known exactly where those targets would be coming from and what their initial vectors would be; but if those targets had only been travelling at one permil, there would probably have been enough time to get in a couple of accurate shots even if they'd appeared totally by surprise.
Ken came to the same conclusion Torra had. "Uh . . . that's not very fast."
"One permil," Jennifer insisted.
Ken exhaled sharply. "Aye, ma'am." He switched to a display of the Human-Centauri system, and began pluggin in the parameters of his intended course. Only one permil, with people shooting at them? Did she not trust his ability to hit the center of the hyper hole any faster than that? "Got a plot," he said a short moment later, and brought it up on Jennifer's messenger display. A long arc overlayed the system, stretching away from the ecliptic and dotted with arrows showing thrust vectors along the course; it merged with the back end of an even longer straight line, three-quarters as long as the entire Habitat Ring was wide. At the far end lay the side of the HC/Sirius hyper hole that, in peacetime, would've only been used by arriving spacecraft. Trying to leave through that side of the hole would have been an accident waiting to happen, were civilian traffic still using it.
Jennifer scrutinized the arrows that peppered the long arc. "Why do you have us at only point-eight gee all the way to the alignment point?"
"Well," Ken indicated Torra with a flick of his palm, "We have a Centaurian aboard. I figured Torra would be more comfortable at that acceleration."
Jennifer shook her head. "Let's not waste time. Replot that at one gee."
Ken was about to protest, but Torra spoke up: "Don't worry about it, Ken. I've flown at one gee with the Colonel more times than I care to mention. Besides, if it's my comfort you're concerned over, my clan's centrifuge spins at half a gee. I'd never want to slow us down that much."
"Okay, replotting," Ken said, and an instant later a new course appeared with a new, shallower arc leading to the new point where they'd intercept the hyper hole's creeping centerline.
"Comm," Jennifer keyed her mike again, "We're sending you our flight plan now," then she forwarded the displayed course as data.
After a brief pause, the speakers came to life again: "Copy your flight plan, Mercurand. Stand by." Another moment later: "Mercurand, you're cleared for undocking and egress."
"Copy clearance, comm," Jennifer keyed her mike in reply, then looked at Ken. "Take us out, flyboy." Though Torra couldn't interpret the facial expression, her smile as she said "flyboy" seemed oddly out of place.
"Aye, ma'am," Ken replied with formal stiffness. "Translating." He nudged a joystick slightly to one side and held it there, engaging the maneuvering thrusters on the docking-bottom side of the spacecraft. The tiny electric arc-jets were more than enough to lift the two-hundred-tonne starship out of its cocoon and clear of the asteroid. Such a launch would never have worked from the surface of a high-gravity air-choked world like Go'orla or Earth.
"We're clear," Ken noted. "Pitching up."
With graceful slowness, the universe began to rotate around Mercurand. It would have made for quite a view from the observation bubble — but that was on the outer hull, and an undocking maneuver carried too much danger of an accidental scrape to allow anyone outside the Command Center. Instead, the cameras on the hull relayed images to the console displays at zero magnification, showing rock and floodlights tumbling gently away.
At last, Ken neutralized the pitch rotation, and announced, "We're vertical. In position for throttle up." He grasped the wide-handled thrust control lever, then released it with a cautious twinge. "Um . . . has this engine design been field tested yet?"
"Well, they said the lab tests were all pretty thorough," Jennifer offered.
Ken's eyebrows wrinkled in worry. "But it's never been tested on an actual spacecraft before, has it?"
Jennifer could only shake her head "no."
Ken hunkered down and grabbed the throttle lever again with a mix of trepidation and determination. "Antimatter powered synchrotron," he mumbled. He couldn't delay much longer, though; the upward momentum left over from their thruster egress was rapidly dwindling, and even in this low .01g they'd start falling back toward the asteroid in a few seconds. "Here goes nothing! Throttling to one-tenth gee."
He eased the lever forward with nervous trepidation. The hum at the back of the starship grew noticeably louder as matter met antimatter and the fruits of their union fed two counterrotating rings of protons and electrons. And at last, they felt the pressure on their own feet. They were accelerating, and the engine hadn't blown up in their faces. The back of the starship was now down.
"We're at two hundred thousand Newtons thrust and holding steady," Ken said with some relief. "Looks like our waste heat is getting dumped into the exhaust nicely too. Good thing, or we would've had to extend the radiators."
Jennifer transmitted, "Comm, Mercurand's egress is complete. Awaiting your instructions."
"Mercurand," the voice came on the speaker again, and there was a tone of calm finality in it, "We're ready to hand you off to civil traffic control. Contact them on their channel, good day. And good luck."
"The plague shall pass," Jennifer signed off, then disengaged the encryptor and dialed in the space traffic control frequency. "HC3 radio, this is Mercurand, we're with you."
A new voice answered, low and with the stuffed-up-nose timbre of a human with a head cold or a Centaurian: "Mercurand, squawk three two two seven and ident."
Jennifer paged a display to show her transponder prominently, then touched 3277 on the on-screen keypad and thumbed the "Ident" virtual button. She could have had the S.I. do all of this for her; it understood radio jargon as well as any trained officer. But whenever she'd delegated such routine tasks, especially to an S.I., she'd had the niggling sense that the delegatee might mess it up or misunderstand her or take liberties that shouldn't be taken. She keyed her mike again: "Sqawking three two seven seven, Mercurand."
"Mercurand, we see you," the voice replied. "Accelerate vector one two six by plus six five at one point zero gee per your flight plan. Be advised freighter tango six foxtrot is on egress from station two-six."
"I see the freighter on my plot," Ken noted. "I'll adjust course to give station two-six an even wider berth."
"Mercurand copies vector and advice," Jennifer radioed. "Sending you an updated course now." She sent Ken's data with a near-automatic touch of the keys.
"Mercurand, course change approved," the controller's voice replied. "Accelerate vector one three seven by plus six zero at one point zero gee per your flight plan. No traffic plots within two thousand klicks of your projected course."
"Copy that, HC3 radio," Jennifer answered, then said to Ken: "You heard 'em."
Ken handed axis control over to the autopilot, and Mercurand wheeled about on two axes until its engine pointed directly away from the little arrow on their course plot. "Throttling up to one gee," he said, grasping the throttle lever once again and sliding it forward. Weight pulled at their feet and torsos, almost crushing compared with the near-zero-gee they'd been working in for so many hours. Torra felt its arms and eye turret sag as it moved them. It guessed that the two humans had it even worse; without a Centaurian's self-locking muscles, they'd have to to exert effort just to stay standing.
"Well, that's it," Ken announced, "We're on course. We should rendezvous with the intercept point in 6 hours 48 minutes."
"This would be a good time for us humans to get some sleep, then. I know it'll take us a good eight hours to run-up to one permil after we reach the intercept point, but during that time we'll be too busy to sleep. There's going to be a lot of last minute preparations, especially if we have to coordinate with our own Gate Guard."
"Good idea," Torra said, opening the gate to its surround-station.
"Wait, you're sleeping too?" Jennifer frowned.
"Um," Ken offered, "Centaurians do sleep for short periods, you know."
"I've never seen the Lieutenant sleep," Jennifer said.
"When we were in Marsinor, my sleep shift came in the middle of yours," Torra told its C.O.. "Sure, it only lasts three hours, but I assure you that if I go more than 3 days without sleeping I run into problems."
Jennifer grunted her acknowledgement. "Well, compared to those 'cushy' Deployers we're all used to, the accomodations here in Mercurand are a little more . . . Spartan. If we're going to be sleeping under 1g, the only place that looks suitable is the hibernation room."
Ken shrugged. "Beats sleeping in my console seat. It's not even a real seatcouch."
"S.I.?" Jennifer cast her voice to the walls.
"I'm listening," Mercurand's built-in brain replied.
"You're pilot-rated, right?"
"Yes," the speakers answered. "I can follow and reply to all traffic controller instructions while the crew is asleep. I will wake you if anything requires your attention or is beyond my decisionmaking capacity."
"Okay, then," Jennifer ordered, glancing at Ken, "Until further notice, piloting duties are hereby transferred from the Navigator to the S.I.. In any case, wake us one hour before we reach the runup intercept point."
"Understood," the S.I. answered.
The three made their way through the short hallway to the room where — if they made it through Sirius and Sol space — they'd be spending most of the trip. It was more cramped than the command center, and far more cramped than the ascender bay. There was barely room to walk between the two 2-meter coffins lying on the thrust floor, and the one meter-and-a-half-tall refrigerator standing beside them.
"Well," Jennifer said as she lay down in her coffin, "Pleasant dreams." She glanced at Torra. "You do dream, don't you?"
Torra bent slighly away in a Centaurian shrug. "Kind of."
"S.I.," she continued, "Night lights." The room lights dimmed to a pale glow. "Oh, and don't turn on any of our S.M.S. gear, we're sleeping, not hibernating."
"Recommend keeping coffin lids and cooler door open," the speakers intoned.
Ken, now horizontal, glanced at the rounded covering swung aside next to him and snorted. "Like I'd want to seal myself in here if I didn't have to." He curled up on one side and shut his eyes.
Just as the Centaurian's own three eyes irised shut, Torra glimpsed Jennifer's mouth broadening into a toothy smile. It almost looked as if she were staring directly at Ken's reclining form. "See you in the morning," Torra heard her croon.
The Pentagon War is continued in chapter 9.
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