"Journeys to the nearby stars are not only possible, they could be done in under a decade. The Alpha-Centaurians proved that. And unless we get travelling — fast — we'll be sitting ducks when those bloodthirsty xorns figure out how to make nuclear weapons of their own."— Col. Ira Henderson,
in his speech to the Earth Committee for Space Travel
Jerry Redlands opened his eyes in freefall. Had the engine stopped? The view was a blur of blue-white light and shadow; he made himself focus. At last, the fuzzy glow congealed into the dusty-tan face of his co-operative beaming back at him — which meant that his casket lid was open.
"Arnie?" Jerry asked, his throat inexplicably dry. "What's wrong?"
"We're there," the man said matter-of-factly.
"What?!" Jerry sat up with a start — if "up" was even the right word for it in microgravity — and discovered he had barely the strength to do even this. "What do you mean we're 'there'? We haven't even passed the Heliopause yet. I wasn't asleep for more than three seconds!"
Arnie shook his head. "Not three seconds. Three years."
Jerry floated back into his coffin, his weakness that much more acute. "Wow. Just like surgical anesthesia. Close your eyes and the operation's over."
Arnie clicked his teeth. "Your 'operation' isn't over yet. The SMS chemical mixture'll take a few weeks to work itself completely out of your system. Actually, in your case, it'll take a couple months, since this was the first time you've been frozen."
Jerry tried to sit up again. This time he had a headache. "Wonderful." Bad enough the Bureau had ignored his repeated pleas to go to Alpha Centauri, and instead had sent him to this dinkball star system he'd never even heard of before; but to do it without so much as an hour's advanced warning! His years of learning about the language, the culture, and the biosphere of the Centaurians' homeworld would be useless out here. He'd always figured there'd be plenty of time to study up on the realities of actually making the trip, of submetabolic sleep and QC&C scramjet engines and all the rest, but this last-minute assignment had robbed him of even that opportunity. And his hastily-introduced mission lead, Arnold Hasselberg, had seemed every bit as impatient as the folks who'd herded him aboard. He'd barely had time to put a single poster up on one wall before Arnie had practially dragged him into the hibernation room. He looked down at his bare torso, groin, and limbs, and suddenly felt very uncomfortable being stark naked in front of a man he barely knew. "Can I have my clothes back?"
Arnie nodded, and plucked a bungeed bundle from beside Jerry's capsule. "Here ya go." He tossed the garments to Jerry; the bundle rebounded limply off his torso and drifted within arm's reach before him. "I chucked 'em into the laundry slot before I went under. Enzyme cleaning can't match a real washer, but at least they won't stink. You can't very well go around wearing clothes that have been dirty for three years, now can you?"
"I've seen some vagrants back on Earth who could," Jerry commented as he pulled his undershorts out from between two bungee cords. He slipped them over his legs.
"Yeah, I believe it," Arnie said snidely, nodding. "Hmmm . . . I wonder what Earth is like these days. . . ."
"You ever been there?" Jerry inquired, muffled by his undershirt as he pulled it on.
"Oh, sure, but that was a long time ago, when I was a tyke." He snorted, momentarily wistful. "And ten more birthdays came and went while I was hibernating on this trip."
"Ten years?" Jerry stopped half way through pulling on his coveralls. "I thought you said we were asleep for three y— oh, wait. Right. Time di—"
"Yes," Arnie interrupted his rambling. "Three years onboard time; a decade in rest time."
Jerry zipped up his jumpsuit and started pulling on a magnetic boot. He knew about time dilation in theory, but he'd never had to face it in actual practice before. A ten-to-three ratio . . . he furrowed his brow. That was an average gamma factor of over 3.3. That sounded way too high for a ten-year trip. "Just how close to the speed of light were we going?"
Arnie smiled like a cat who'd just caught a mouse. "At the midway point, we hit ninety-nine and a half percent of it. For that brief moment between thrust and braking, our clocks would've been running only a tenth as fast as the clocks on Earth."
Jerry balked. "Ninety-nine and a half percent of light speed — point nine-ninety-five c, nine nine five permil, did I hear you right?"
"That's right," Arnie cocked an eyebrow. "Nine nine five permil."
The biggest conundrum in interstellar flight was covering such enormous distances in less than a human lifetime. The Heliopause, the farthest reaches of the solar wind, three times more distant from the sun than Neptune — take that whole enormity, surrounding the solar system on all sides like a distant, distant shell, and shrink it to the size of a grapefruit. At this scale, the sun is a microscopic dust mote at the center with the Earth orbiting half a millimeter away from it; yet the Alpha Centauri star system would be another grapefruit sitting 130 meters away — the span of a city block. And Alpha Centauri was only Sol's nearest neighbor in space; this unfathomable gap grew ever-larger for the more distant stars. The star system they'd just arrived at, Luyten 726-8, lay 8.55 light-years distant from Sol, almost exactly twice as far from the sun as Alpha Centauri was.
Even with the quantum confinement-and-constriction technology we humans had stolen from the Centaurians, which made proton fusion a practical and efficient reality, a rocket's exhaust velocity was only a hair over a tenth of the speed of light; and everything a rocket could do depended on its exhaust velocity. The typical interplanetary craft that plied the space between Earth and Saturn took three-and-a-half days to accelerate to 1 percent of light speed — "ten permil," the pilots called it — then turned around and decelerated for the same length of time 'til it reached its destination. At that 10 permil speed, it would take 430 years to cross the 4.3 light-year gulf separating the Sol system from Alpha Centauri. No one wanted to wait that long, but greater speed incurred ever-spiralling costs. If you built a behemoth of a spacecraft with 95% of its mass devoted solely to fuel, you would still run your tanks dry by the time you hit 330 permil, just one-third of light speed — and you'd have no fuel left to slow back down. You'd have to accelerate to only half that speed in order to save enough fuel for braking, leaving your travel time to Alpha Centauri still at an uncomfortably long 26 years.
There was a way to get more fuel, though. Interstellar space wasn't a complete vacuum; in the local "fluff" within a dozen or so light-years of Sol, it contained about 1 atom of hydrogen for every 10 cubic centimeters. Roughly half of that hydrogen was ionized, with its positively-charged nucleus and negatively-charged electron separated from each other, and ions could be drawn in by an ordinary magnetic field. Throw such a Bussard scoop field out in front of your starship some nine thousand kilometers across, and at a tenth of the speed of light you'd sweep up about 150 grams of ionized hydrogen and free electrons per second.
You could use this swept-up star stuff to replenish your fuel tanks, or cram it directly into your fusion reactor, but then you'd have to slow it down, or rather, make it match the speed of your tank or reactor — and that would cause unavoidable drag. The faster the onrushing hydrogen was going, the more drag you'd get when you braked it to a halt. You'd never be able to go faster than your own exhaust velocity.
Fortunately, the Centaurians had already come up with a better solution. The interstellar scramjet.
Modern starships ran the gathered interstellar hydrogen through quantum confinement at the same speed it got scooped up, and induced nuclear fusion without slowing any of it down. Negligible slowing of the reactants meant negligible drag. Just like in a conventional fusion reactor, the containment cells converted the gamma rays released by the reactions into electric energy, only now the reactants were coming from the outside and zipping down the gullet of the spacecraft at near light speed. They used this captured electric energy to accelerate the reaction products as they flew by, squeezing every last bit of specific-impulse out of the process that the laws of nature would let them get away with. Once up to speed, they could sustain a full g of acceleration indefinitely. And of course, the scoop field was also good for slowing down if it was de-tuned in flight, à la Zubrin's magnetic sail, and using the scooped-up material to replenish your fuel tanks while braking was practically a given. After all, you would have used up your entire initial fuel supply getting yourself up to ram-scooping speed in the first place.
But at one g, accelerating for five years then decelerating for another five as seen by the outside world, their top speed should only have been about ninety-eight percent of the speed of light, not ninety-nine and a half. That one-and-a-half percent difference sounded tiny, but in the Einsteinian universe so close to the speed of light it represented double the kinetic energy.
"You want to know how we managed to top out at 995 permil?" Arnold went on. "It's simple. We accelerated at two gee for most of the trip. Our fuel tanks are big enough to push us all the way to two hundred permil at a steady two gee, at which speed we're scooping in hydrogen fast enough to sustain a full gee with no internal fuel of our own. By four hundred permil, we're back up to two gee again. This isn't one of those flimsy liners that can't pull more than a gee without crumpling; this starship's built to take it. When the SBI issued it to me eleven years ago, it was absolutely top-of-the-line."
Jerry secured his second magnetic boot, and tried to stand. He was still so weak that if there had been any gravity, he wouldn't have been able to do even that, and it still wasn't easy in weightlessness. "I'm surprised the Bureau gives anything 'top-of-the-line' to its agents."
Arnie clicked his teeth again. "What I do is pretty special to them."
"I would imagine." Jerry massaged the stiffness out of his back and legs, then glanced around to pick a horizontal surface for his feet. Arrows labelled "Engine thrust floor" pointed to the wall his coffin was bolted to; the arrows pointing to the opposite wall said "Braking floor." Almost rebelliously, Jerry put his feet on the side wall in between them and tried the magnets. It would feel good to walk around again. "That continuous two gees must be why we had to be put into suspension."
"Among other reasons, yes."
Jerry took a few steps forward. The electromagnets on his boots cut on and off, appropriately, as he stepped. Not that he was in any danger of floating away; the corridors were much too cramped for that. An in-system spacecraft could afford to have a spacious interior, but a starship was another matter. He looked wistfully at the room that had housed him, unconscious, for the last three (or ten) years, and asked, "Does this spacecraft of yours have a name?"
Arnie shrugged slightly. "November kilo four three eight charlie hotel five."
Jerry shook his head, "No no, not its registration number, I mean something more personal."
"What, you mean like HMS Pinafore or the Spruce Goose? Don't be silly, this is a piece of hardware, not a person." Arnie pursed his lips in thought. "Although, since the voice they gave to the S.I. is pitched in the feminine range, I sometimes address it as 'Doris'."
Jerry chuckled once, which was still a bit of an effort, though his head was finally beginning to clear. "Speaking of your rather unique service to the Bureau, is it true that everything the Mad Scientist concocts works out exactly like he says it will?"
"He's had a few little failures, to be sure, but every big idea he's undertaken has worked out — every single one of them."
"This one must be pretty big for you to requisition a partner," Jerry commented. "Even if I've never been outside the solar system before."
"I didn't requisition you, you were assigned to me at the last minute."
Arnie shook his head. "Darned if I know. I haven't looked at my orders yet."
Jerry glared at his co-operative. They were eight-and-a-half light-years from home, and he still hadn't read their mission orders? "And why not?"
"Because we're supposed to look at them together, once and once only, when we arrive. That's why I came here to thaw you out just now."
"Uh huh. You said we were 'here'."
"Yep." Arnie didn't seem to care for the hassle of magnet-walking. He pulled himself through the hallway hand-over-hand like a monkey swinging from tree branches, until he reached the side door. There, he pushed the button which made the door slide apart, and crossed to the curtains on the far wall of the room beyond. "And here we are." He drew the curtains wide and bathed both rooms in vermilion light. A bloated, red-orange disk shone through the window and dwarfed the blue-white fluorescent glow to which they'd grown accustomed. "UV Ceti."
Jerry instinctively put up a hand to block the glare. Even through the window's reflectorized coating, this miniature reddish sun was nearly blinding — and this close it was seven times as big across as the sun seen from Earth. As their eyes adapted, a yellowish tendril of flame resolved itself on the star's right side. The tiny sun was less than a sixth of the diameter of Earth's own Sol, and twenty thousand times dimmer; yet the flare they now witnessed was just as bright as, and reached a hundred times farther and wider than, any flare Sol had produced in four billion years. There was enough radiation in that one flare to wipe out the dinosaurs or bring on another ice age, if Earth had formed in this star system.
"Better get used to it, Jerry," Arnie said, "'cause flares like that one are gonna happen every day."
Jerry stared at the fiery demon. "Aren't they dangerous?"
"You bet. That's why there isn't a trace of life anywhere in the system. Except for us and the Mad Scientist, of course. Any planet close enough to the star to not freeze over would be close enough for those flares to fry it. In fact, we shouldn't stay in this room too long; the window glass isn't very good at stopping X-rays."
Nevertheless, Jerry clomped into the room. He had to get a better view. "Show me where our new home is going to be."
Arnie pointed at the bottom of the curved glass plate. "Down there." Jerry could see the top edge of a lumpy, cratered surface, like an extreme closeup of a dirty golf ball. Off to one side, in the blackness above it, lay an equally-desolate beach ball, showing only an orange crescent sliver lit by the reddish sun.
Arnie moved his pointing finger to the orange crescent. "Desolate, downtown UV Ceti IV. A lifeless chunk of granite with a hydrocarbon atmosphere just barely thick enough to be annoying. This close to the star, the tidal forces are strong enough that it's locked in synchronous rotation with it; one side of the planet's in perpetual flare-addled daylight, the other's in perpetual darkness. It's one of the least-prized pieces of real estate in known space — which is why they let the Mad Scientist have it."
"Hm," Jerry mulled this over. "UV Ceti IV sounds like such a boring name."
"It's a pretty boring place," Arnold replied. "But if you'd prefer, the yahoos over in the IAU did make up more colorful names for every planet in this system. Since we're in the constellation of Cetus, as seen from Earth, all the names are whale related. The planet closest to UV Ceti," he pointed just a hair off to the left of the star, "is Jonah. The second one's Moby, the third one's Yu-kiang, and the fourth one, UV Ceti IV here, is Namu." Arnold pointed once again at the huge golf ball beneath them. "That cratered ball of wasteland is Namu's only natural satellite. Just like one side of the planet always faces the star, one side of that moon always faces the planet. That makes it a perfect vantage point from which to keep an eye on the Mad Scientist."
"What?" Jerry shook his head. "You mean we're not going down there on the planet with him?"
Arnie inhaled, clearly uncomfortable. "I've been on the same planet as the Mad Scientist once, and I was scared out of my wits the entire time. There's a reason the Solar government gave him his own planet to work with. Now come on; it's time to read our orders. I want to find out why the SBI wants us to spy on him this time."
Jerry followed him out of the viewing room and back through the fluorescently-lit chamber they'd both hibernated in. Jerry could feel his strength returning, but slowly. He wondered if enough of his strength would come back to stomach his orders.
Namu's airless moon beamed its lumpy crescent greeting down on them through the overhead window. They were standing on what would have been the ceiling had the main engine been on. Arnie ceremoniously ripped the end off the red envelope, blew it open, pulled out the three-inch-square shiny wafer, and flashed it in the light. Slowly, he positioned the square before a slot beneath a meter-wide display screen. He shrugged. "Well, here we go."
He popped the square into the slot. Jerry rubbed the last traces of grogginess out of his eyes, blinked hard once, and focussed. The screen flickered to life and a middle-aged woman's face, framed against the emblem of the Solar Bureau of Investigation, spoke its pre-recorded gospel.
"Arnold Hasselberg." She nodded. "Jerrold Redlands. Gentlemen. First, Arnold, let me apologize for forcing you to work with an operative. I understand that you do your best work alone, but should you not survive, this mission is far too vital not to have someone else to report in for you. Secondly, Jerry: I know you requested your first interstellar voyage to be to Alpha Centauri A III, but again, this development takes precedence over your getting involved with the counter-culture you so enjoy."
Counter-culture? Jerry balked in thought. The homeworld of the only other intelligent species in the known universe, and she calls it a little enclave of Beatniks?
He glanced over his shoulder to a 3-D poster he'd pinned up in this room before they'd left the Solar system. It displayed a depth-enhanced portrait of Cronazza Heap, who was Chairholder of the entire Human-Centauri star system . . . and a Centaurian. The being's tanned, mottled skin seemed almost inconsequential against the cylindrical torso it covered, which made up most of its height and bulk. Four long arms protruded radially just below the top of the cylinder, which rested on four stubby legs ending in feet with biological wheels embedded in them. Between each of the four arms, just below the shoulders, were four separate mouths. From the top, a three-pronged eye stalk gave it 360 degree, if non-stereoscopic, vision — ironic, considering the 3-D format of this poster. Its only other sensory organ, its ear, lay hidden in the middle of its three eye stalks. The half-meter-high stereogram represented a perfectly average-sized Centaurian, 132 centimeters tall.
Cronazza Heap also sported something few Centaurians bothered with: a slender sash around its midsection. Most Centaurians went around completely naked; clothing couldn't lend warmth to a cold-blooded creature, and there was little use for sexual modesty in a species that didn't pair-bond with its mates — and for which every individual was both male and female at the same time.
Despite the obvious physiological and social differences, though, life on Alpha Centauri A III showed an amazing degree of parallel evolution with life on Earth. They had RNA and DNA, and even used the same four nucleotides — albeit with a different genetic code. Centaurians were within an order of magnitude of human sized, with a sense of touch over their entire skin surface and the rest of their senses in one bundle on top. Although they had four mouths, they used each one for eating, breathing, and talking, just like we did. And most remarkably of all, in the four-billion-year history of life on both planets, a spacefaring species had emerged on each one within only a few centuries of the other.
Jerry slowly turned his attention back to the recording as the woman continued: "The Mad Scientist has come up with some strange plans in the past, but nothing to match the potential strategic importance — or the cost — of this one. His idea is an application of known principles that's so simple it seems almost childish."
She explained: "The output of an electron-positron pair annihilation is always two gamma ray photons, whose total energy . . ."
Jerry didn't register the next few words. He forgot to listen when she said "positron." Antimatter. This was big stuff indeed.
" . . . is the mass of both annihilated particles times c-squared. Proton-antiproton and neutron-antineutron annihilations put out gamma rays plus a few pions as well, although the pions decay into gamma rays a few microseconds later. It's because of this delay between an antiproton annihilation's initial gamma-ray burst and the decay of its by-products that the Mad Scientist's plan calls for only positrons and no antiprotons."
What the speed of a matter-antimatter reaction had to do with the power of the explosion, Jerry could only guess. As far as he was concerned, antimatter bombs were antimatter bombs, and if it took an extra millionth of a second to squeeze all the gamma rays out of a proton-antiproton reaction, what difference did that make?
The recorded woman continued. "The principle he seeks to exploit here is that of Stimulated Emissions. Any physics student will tell you that if a photon of the correct frequency passes close enough to an atom in an excited state, that atom will emit its own photon of the same frequency, perfectly in phase with the photon that triggered it. This is how lasers work. The two in-phase photons travel in a single packet, both in the same direction. And a third photon, also emitted in phase, will travel along with the first two. As will the fourth, and the fifth, et cetera, until you have one big coherent beam all going in one direction and one direction only. There are almost no 'stray' photons going off in random directions, as there are with an incoherent light source, so all the photons will strike the same point on any target in their path. This is why laser beams are so much more intense than ordinary randomly-phased light.
"Two months before this recording was made, the Mad Scientist handed our Board of Research Funding a proposal based on a theory almost too mind-boggling to be true. In brief, his theory stated that the phenomenon of phased emissions could also occur in a multiple positron-electron reaction, if the two masses of particles were aimed precisely at each other and there was enough matter and antimatter reacting to flood the immediate space with gamma rays. He contended that the gamma rays must be close enough to the second wave of reacting particles to stimulate them into annihilating into another gamma ray photon in phase, so there had to be a lot of them. Even using the most efficient explosive lenses available, he went on, such a reaction couldn't be guaranteed with anything less than five hundred kilograms of positrons and electrons."
Jerry's eyes bulged wide. Even Arnold seemed to lose his cool for just a moment. Did she really say five hundred kilograms of matter and antimatter? Not 500 grams, 500 KILOgrams?!
Her pre-recorded face leaned closer to the playback screen. "All the pair-creation facilities at Sol's disposal, working in concert at full yield, would take days to collect only a single kilogram of positrons. We're talking about two hundred fifty times that amount. Two hundred fifty kilograms of antimatter reacting with 250 kilograms of ordinary matter would produce ninety exajoules of energy. That's over twenty trillion kilowatt-hours, enough to power a large city for over a decade — or flatten a small continent if released in, shall we say, a conventional antimatter bomb. If the Mad Scientist's latest idea works as well as all his previous ones, this same five hundred kilograms reacting in phase would focus the entire output of such an enormous antimatter bomb into a single beam, capable of cutting through just about anything of any size.
"Needless to say, most of the Board was skeptical. Never mind that phased antimatter reactions had never been seen before under laboratory conditions; just building a device to test this theory required the majority of Sol's entire positron stockpile. But the theory was sound. The Mad Scientist's blueprints for a test device passed every scrutiny. The Board gave his Phased Antimatter test project the go-ahead. All pieces of his device that could be assembled prior to shipment were put together and sent on unmanned ramscoops to the fourth planet of Luyten 726-8 B — the UV Ceti system — twelve years prior to the time when you should be reading this message. The Mad Scientist had embarked on a slower craft for the same system the moment the project was approved, two years earlier.
"With a quarter of a million grams of positrons all in the same room together, there is a very real risk of magnetic containment failure. The Mad Scientist and all the recording equipment he's documenting this experiment with could evaporate in a heartbeat. This is why you've been assigned to monitor his progress from a safe vantage point on UV Ceti IV's moon. You are ordered to establish an observation base on the moon, gather all information possible regarding the Phased Animatter experiment from there, and return it to the SBI once the experiment is at an end.
"Your presence here and any information you gain is classified Top Secret. I don't have to tell you the experiment's strategic implications should it prove successful. Head of SBI strategic surveillance, out."
A red light flashed twice in the lower right-hand corner of the screen, and the message wafer popped back out of the Read slot, its circuitry smoking from a brief but intense current overload.
"A bit dramatic, I'll admit," Arnold commented as he looked the wafer over to be sure all data areas had been destroyed. "The Bureau doesn't like to leave secrets lying around any longer than necessary — even if there are no other humans or Centaurians within eight light-years."
Arnold took to his feet without another word, and Jerry followed suit. They both knew the drill; though they'd learned it decades apart, on equipment as different as a campfire was from an electric toaster, the basics never changed. Open the Ascender's hold, which had been packed and double-checked even before they'd left spacedock; check the pressure tent to ensure that it had survived the trip intact; run down the checklist of all the packed provisions and gear one last time, just to be doubly safe; shut the hold and check its seal indicators; make one final check of the cabin's emergency equipment; and then they'd seal the hatches, strap themselves in, cycle the starship's airlock, and push their ascender free.
But before they sealed themselves in, Jerry had to retrieve his poster.
"I've been meaning to ask you about that," Arnold said as his assigned partner magnet-walked back with Cronazza Heap in tow. "If you like Human-Centauri so much, why don't you just go live there?"
"Oh, no," Jerry assured him, "It's nothing like that. Human-Centauri's way too much like a cult for my taste. Hell, their whole 'emotional plague' concept is practically a state religion, even though they'd never let you call it that. I just admire what the Heap clan's been able to accomplish there. Sixty years ago, it wasn't even a star; they just called it Haberd's Brown Dwarf 629. They managed to light it up, and build homes for themselves, and now they've got an entire network of inhabited, satellite-ringed asteroids around the star, with some enclosed areas big enough to have their own weather systems."
"Kinda like the Mormons," Arnold opined.
"What's really remarkable," Jerry continued, "is how well the Centaurians there were able to coordinate their efforts with the Humans for Better Interspecies Relations. The more I learn about Centaurians, the more amazed I am that any group of humans could pull off such a monumental act of cooperation with them. It took me years to be able to comprehend even their basic vocabulary when they speak it at full speed, and that was after I'd learned their written language cold."
Arnold raised his eyebrows, clearly impressed. "You speak Centaurian?"
Jerry shook his head. "I understand spoken Centaurian when a Centaurian speaks it. No human can pronounce it."
Arnold put his fists to his hips in disbelief. "Come on!"
"You know they have four mouths, right?" Jerry sounded almost condescending.
"I've heard," Arnold replied.
"That's four separate vocal mechanisms," Jerry explained, "And their language uses all four of them at once. You try speaking in four-part harmony! You'd need a barbershop quartet to even try."
"Oh, come on, Jerry, it can't be all that bad. I mean, their word for Alpha Centauri A III is just 'Gorla,' right?"
"It's Go'orla," Jerry corrected him, making an awkward gesture with his mouth on the first syllable. "There's an apostrophe between those two o's, which means the Centaurian speaking the word is supposed to switch to a different mouth in mid-vowel. The way you said it, it sounded more like goor(l)a, which means 'the clan's bookkeeping expert' — and to pronounce that word correctly the speaker has to make 'or' and 'ol' sounds at the same time on two different pitches a minor-third apart. It's a good thing Centaurians only have one ear, or they'd probably have stereophonic words too! And the mechanics of their spoken language is only the first hurdle a human has to overcome when interacting with them."
"You mean like the fact that they still can't figure out how to make computers?"
"Now, that's not fair," Jerry chided him. "They don't just blindly copy our computer technology, they have digital engineers and software programmers of their own. Their brains just aren't wired to make the kind of abstract leaps that led us to invent computers in the first place. And need I remind you, none of us had ever thought of quantum confinement-and-constriction before the Centaurians came along, either."
"But now that we have," Arnold retorted, "We've made just as many strides in using QC&C technology as they have. The very spacecraft we're sitting in outperforms anything the Centaurians have put in service, and all of the improvements that led to it were made by us humans. Before the Centaurians, it wasn't like the technology was completely beyond our grasp, it's just that we hadn't stumbled across it yet. It's like the Centaurians and nuclear weapons — there weren't enough radioactives in the crust of Alpha Centauri A III capable of a sustained chain reaction, so they just never thought of it."
Jerry dropped the subject abruptly. "Well, come on, let's stop dawdling and get in," he said as he pulled himself and his poster through the ascender's outer hatch. The whole subject of Centaurians and nukes had never sat well with him. It was inextricably intertwined with the first meeting between the two species — and, of necessity, with the second.
Arnold clambered in behind and twisted the latch-wheel taut, sealing the two of them off from their mothership with a comforting clack. A flick of a toggle slid the inner airlock door into place a fraction of a meter in front of the outer hatch. As he approached his seatcouch, he fished two small pouches out of his side pocket and handed one to Jerry. "Here, better drink this now."
"Glucose solution," he explained. "Plus some cultures to help repopulate your gut flora. Nothing's gone through your digestive system in three years. It'll take a day or two before you readapt to solid food."
"Mm," Jerry grunted, and squirted some of the concoction in his mouth. He grimaced at the taste, which reminded him of some of the worst candy he'd ever had while visiting the State of North Africa as a child.
Arnold toggled the master switch, starting the little ascender through its automated power-on self-test sequence. One by one, lights and fans and displays all came to life on the cramped panels around them, bristling with diagnostic data, software version information, and the occasional flicker of a company logo. Arnold seemed to ignore it all. If anything was out of whack, the ascender would tell him, and thus far it never had.
Jerry took a cursory look around the tiny cabin, to reassure himself that — ah, yes. The microgravity commode and urinal funnel hose were right where they should be, next to the recycler. He'd probably need to use the urinal before they finished setting up their base camp.
When one specific panel lit up to tell him it was ready, Arnold switched on the radio transceiver and keyed his headset mike. "Doris?"
"I'm listening," came the woman's voice over both of their headphones.
"Cycle open the docklock. We're leaving."
"Commencing ascender bay decompression and release sequence," the feminine voice intoned.
Jerry thought he could hear the vaguest hint of a sucking sound from outside the ascender, overshadowed by the low hum of the cabin's own machinery, but this sound soon trailed off into nothingness. His miniature spacecraft was now in vacuo. Through the left edge of the main window, he watched majestic doors soundlessly pull themselves apart, exposing the jet-black of space beyond. The bay's ambient lighting made it impossible to see the stars studding that inky blackness, but that would soon change.
Arnold tapped a control lever, watching the readouts and listening to the faint puffs and hisses with a trained ear. "RCS thruster quads are all green and firing," he commented for Jerry's benefit, then keyed his mike again. "Cut us loose, Doris."
With a clack and a bump, the docking clamp package disengaged, severing their union with the starship.
"I'll go easy on you," Arnold quipped as he deftly nudged out of the docking bay and into the cold void. "This'll be a ballistic descent trajectory. No Brachistochrone stuff, no accelerations higher than half a gee; just a plain old deorbit burn, a lazy coast down toward the landing site, and some slow terminal braking. Think your stomach can handle that?"
Jerry nodded absently. A tiny side window in the Ascender happened to be pointing directly at the starship they'd just drifted clear from, and his attention focused on their slowly-receding former home. There was the narrow but long — very long — wire mesh cone sticking out of the front; this was the collector field generator, which had drawn in the onrushing interstellar medium while they'd been at speed. He'd glimpsed it during his quick boarding flight prior to their departure from Sol space, and had marvelled at its shape. That same kind of wire mesh existed, though on a much smaller scale and with a decidedly different shape, inside the "magnetic snares" employed on some fighting spacecraft. On a scramjet, though, it had to be long and narrow to shape the collector field, or else their own drag would have lengthened their trip to a century. Mounted at the base of the mesh, and barely visible from this angle, was the multimegawatt ultraviolet laser that swept the space immediately in front of the starship. It existed because half the interstellar medium wasn't ionized; the ultraviolet beam electrically charged all the neutral hydrogen, heavier atoms, and assorted dust grains that had been directly in their path. Left uncharged, these microscopic bullets would have passed right through the collector field and slammed into the hull; and at 0.995 c, a single dust grain would impact with the force of five times its mass in antimatter.
Then, there was the long boom sticking out behind the fuselage. Jerry didn't remember seeing that during the boarding flight. At the time, it had been obscured behind four bulging, watermelon-shaped fuel tanks that ran its entire length. But now those fuel tanks were nearly empty, and being mylar-thin cryogenic balloons they lay shrivelled up next to the fuselage, exposing the boom's full, sweeping extent. The boom clearly housed the QC&C fusers at the scramjet's heart. Why did they waste so much mass making it so long? Couldn't they have engineered the fuel tanks to be spherical instead of watermelon-shaped when they were full, and thus made the boom a lot shorter? Then it hit him. The nuclear fusion process happened in two stages, proton-protium and deuteron-deuteron. The products from the first stage had to be handed off to the quantum confinement cells of the second. Since the reactants all had to shoot through the belly of the spacecraft at up to 0.995c, the hand-off between the reaction stages imposed a separation of meters as well as nanoseconds.
Jerry also hoped those shrivelled fuel tanks were refilling themselves now from the stellar wind, so that they'd be ready to give the long, hard push to start their journey homeward after their work here was done. After all, their mothership certainly weighed in at hundreds of tonnes with its fuel tanks empty. For a craft that large, even the widest scoop field still had to plow through the interstellar medium at over a tenth of the speed of light before it could gather enough hydrogen to sustain just half a gee of thrust on its own.
Jerry turned his attention back to the front window, and something caught his eye. He pointed to a pinkish spot of light in the window, as bright as the full Moon seen from Earth. "What is that?"
"You mean Luyten 726-8 A?" Arnold half-chided his companion. "We are in a binary star system, you know."
". . . Oh," Jerry replied sheepishly.
"Y'know, it's a flare star too, just like UV Ceti here. Even has its own variable star designation: BL Ceti. Not as famous, though, 'cause its flares are a lot less violent. In fact, if it had planets, they'd probably be pretty desirable pieces of real estate. But no — all the planets in this binary system formed around UV Ceti, so we're stuck with it."
Jerry glanced down through the main window at Namu, just as it emerged from behind the limb of the moon below them. "That planetary formation period must've been pretty interesting, and a whole lot different than Sol's. The moon down there looks like a captured asteroid, but it's a huge one."
"Not that huge," Arnold shrugged. "It's only 120 klicks across. Heck, the surface gravity's only about half a percent of a gee" — he glanced at a calculated reading on his panel — "and the escape velocity's barely 80 meters a second at the surface! If you were standing outside, you could almost throw a baseball hard enough to put it in orbit."
Jerry frowned. "You said we were just going to coast down to the surface. Um . . . with such a shallow gravity well, how long is that going to take?"
"About an hour and a half," Arnold smirked.
"I can see why nobody bothers with ballistic trajectories any more." Jerry sighed. "Well, you'd better get started on the deorbit burn then."
"Already done it," Arnold replied.
"Huh?" Jerry rubbed his temples. "I don't remember you powering up the main engine."
"For only 7 meters per second of delta-v?" Arnold chuckled. "I let the thrusters handle that. They use tiny electric arc-jets instead of hypergolics, so we don't need to worry about wasting propellant — much. We deorbited as soon as we cleared the docking bay. I'll warm up the main engine when we're about to touch down, just in case of emergency, but on a rockball this small the thrusters'll be more than enough for landing too."
Jerry had heard him when he'd said "only about half a percent of a gee," but the reality of this didn't sink in until that last sentence. Landing a spacecraft with just the reaction thrusters! That wasn't a landing, that was a docking maneuver. His next months in the pressure tent would be spent in gravity hardly stronger than weightlessness — with no ferrous floor on which to use magnetic boots.
He hoped the working environment inside the tent would have enough hand-holds.
In any event, there were a good ninety minutes to kill before he'd have to worry about it. "So," Jerry began, "Tell me about that one time you were on the same planet as the Mad Scientist."
Arnold shuddered briefly. "That was a long time ago. It was also the first time the Mad Scientist did anything Sol considered worth spying on. They sent him, and me, to one of the outer planets in the Lalande 21185 system. Of course, we weren't the only ones going — we were just part of a larger scouting party, tasked with evaluating all the planets in the system for potential colonization. Sol was really interested in Lalande 21185 as another location to branch out to . . . you know, until they got word that Sirius had declared independence. That really put the brakes on all of our plans to —"
"Wait, wait," Jerry interrupted him, "Do you mean to tell me that you were already old enough to be sent on an interstellar mission before Sirius broke off from Sol? That was 112 years ago!"
"I told you it was a long time ago," Arnold shrugged.
"Just how many years have you been in suspended animation, in one form or another?"
Arnold merely smirked and turned back to his controls. "Actually, for that first mission, we didn't use hibernation technology; it was still too crude and too risky, and didn't get better until we started playing catch-up with the Centaurians. Hell, we didn't even know Centaurians could hibernate until they stupidly sent their own colonists to Sirius just a hair later than ours. So . . . I had to live aboard that spacecraft. Even with the time dilation, that was five years out and five years back. I got married and divorced twice on that trip, and produced a daughter and twin sons in the process." He briefly turned to face Jerry. "Never seen 'em since. They grew up and had respectable careers all without leaving Sol space; the three of 'em retired decades ago, and one passed away from ripe old age a year before I left on this mission." Arnold sighed. "We can put a man on Sirius A IV, but we can't make him live longer."
Jerry swallowed hard. He would eventually return home from this mission, and two decades would have passed for everyone he knew. All of his old friendships would have long since withered. He'd have to make new friends, a generation younger, all over again. And, later, if and when the opportunity arose to follow his youthful ambition of visiting Alpha Centauri, he'd have to give up those new friends too.
"You know, it's a little ironic," Arnold backtracked ever-so-slightly. "When Sol got wind of Sirius breaking off from them, we could have stopped them cold. We had a pretty big fleet of combat starships, in case we ever decided to attack Alpha Centauri. If we'd sent all those spacecraft to Sirius, or even just the bulk of 'em, we'd have had more than enough firepower to pound the Sirians back into submission. But what did we do? We sent one fighter carrier. Sirius has had a century of laughing at that feeble gesture to build up their defenses; now they're too big for us to retake."
"And as long as Sirius exists as an example for the politicos to point fingers at," Jerry added cynically, "The Solar Federal Government won't even think of starting up a new colony around another star."
"You know it," Arnold sighed. "Hell, they haven't even granted statehood to any territory within the Sol system since Ganymede. That kind of paranoia's holding Sol back way too much, if you ask me."
Loyalties to Sol aside, Jerry could hardly help but notice that the same kind of paranoia had gripped Alpha Centauri 28 years later, when CN Leonis had broken off from them. And yet, both systems had let the Humans for Better Interspecies Relations, and its Centaurian counterpart, take off in their own spacecraft to build Human-Centauri years later.
Jerry settled silently into the slow descent, letting his mind wander from topic to topic until he hardly noticed his surroundings. Eight minutes later, the S.I.'s womanly voice snapped him back, barking from his headset: "Blood analysis complete." It hadn't been any louder than the last time it had spoken, but after so long a silence the sound was quite jarring.
"Blood analysis?" Jerry asked.
Arnold glanced over at him. "I took a little of your blood before you woke up. It's standard procedure, in case anything went wrong while you were under. I gave the S.I. some of my blood, too." He keyed his mike. "Go ahead, Doris."
"Jerry's blood contained CK19 cells. Gene sequencing confirmed two hyperdivisive mutation sites."
Arnold raised his eyebrows. "Hm! Looks like you picked up a metastatic cancer while you were in SMS."
Jerry worried. "We won't have to go back to the starship to synthesize the counterbodies, will we?"
"Of course not. What do you think the SBI is, a bunch of primitive savages? There's a protein assembler in our first aid kit, just like in any liner or hotel room. In four days' time, the S.I. should've found a folding solution that'll fit your expressed mutations, and will send us the amino sequence. I can order her to break radio silence for that, even send it in the clear, and I'm sure the Bureau won't even raise an eyebrow. You'll be cancer-free by the end of the month."
The rest of their descent drifted lazily by, until at last the onrushing ground got too close for comfort. Arnold typed a console command at the ascender's only true keyboard, and the tiny craft began to hum — softly at first, then steadily louder, until finally the hum dropped two octaves in pitch. The full, frightening power of the hydrogen-and-deuterium-burning hot-fusion engine was now available at an instant's notice. But Arnold didn't need it; a tug on the translation lever, and the gentle thrusters soon cancelled their 65-and-a-half meters per second of horizontal velocity. "Biggest danger on these soft landings isn't crashing," Arnold explained, "It's bouncing. We don't want to end up rolling the ascender over on its back. We wouldn't be helpless if we did, we could always use the thrusters to lift back off again from any angle, but it's never good for the hull to go banging around on a rock. Even if the nosecone is built for atmospheric egress."
The feet of the ascender touched down on the rough, pockmarked surface, as gently and deftly as the hand of a tender lover. Say what he would about his partner's many quirks, Jerry told himself, but as an ascender pilot Arnold Hasselberg was good.
"Anchors out," Arnold chirped as four bangs reverberated through their tiny spacecraft, each setting Jerry's nerves on edge. Those were the four piton lines shooting out of the bottom and punching their way through the rock below. In the low, low gravity, you didn't want your only way home to go bounding away just because you nudged it. Arnold shut down the main engine, checked a reading to make sure all was well, then announced, "Let's deploy our new home" as he flicked a covered switch. Whirs and hisses filled their ears. Jerry craned his neck to see out a window that faced the horizon; the side of a rapidly unfolding and inflating tent, the pressure tent, glinted orange in the light of UV Ceti. In a few moments, they'd open the airlock, and step out into a millimeter-thin shell of plastic separating themselves from the vacuum. Once they'd unpacked, it would contain everything they'd need to survive and reconnoiter in the months ahead.
Jerry dreaded the thought of the impending boredom, but dreaded the thought of any excitement their environs might throw their way even more.