A Sword Into Darkness (6 page)

“My, my, how specific.”

Lee had a drink.  “You did say exactly.”

“Well, from what you’re saying, several methods present themselves, but are we even sure this is an invasion?”

“No, we aren’t.  Let us say that this hypothetical alien visitor has made no attempt to contact us by signals, or at least there has been no attempt that we have recognized.  Also, the distances are so great that there is no way for us to have yet received a response to our own attempts at communication.  And since we can think of no reason for this unknown alien species to physically come to us other than for invasion, we are proceeding upon a worst-case scenario.”

Nathan’s pacing was now more rapid, purposeful.  “But they are an alien race, correct?  So ascribing our own reasoning on them is an uncertain proposition, wouldn’t you think?”

“Of course.  Alien race equals alien reasoning.  Perhaps they are coming here just to say hello, or to plant poppy seeds and welcome us to the inter-galactic love fest.  But why not just contact us with a radio signal?  Radio signals are undoubtedly how they discovered we were even here in this universe, so our common sense would seem to suggest that if their intentions were benign they would have called before stopping by for a visit.

“Now, that common sense is really just the laws of motion and thermodynamics expressing themselves in our everyday reasoning, laws that the aliens are also bounded by.  If their intentions are benign and they wanted to avoid conflict, it makes sense to make initial contact through signals.  Signals move at the speed of light, and are transmitted at a relatively low power level.  For a species forced to travel below that speed, think of all the time wasted, all the energy wasted in coming here physically.  Signaling us is safer, faster, and cheaper.”

Nathan stopped and looked at Lee.  “All right, it’s your game.  If you contend that their worries about time and energy expenditure are identical to ours, then their reasoning might be similar to ours as well.  So, the only reason for them to come here is that they need something physical from us, like our resources or our women—Mars always needs women, after all.  And because they didn’t call first or yet, we have to assume their intentions are hostile.”

“That’s right, but you’re dancing around the question, Mr. Kelley.  How do you stop the potential invasion?”

Nathan started to walk back and forth again.  “Well, since we’ve established how they’re getting here and confirmed their intentions, the next step is to know the enemy.  We have to conduct reconnaissance at the earliest opportunity.  How far away are these aliens who are taking 22 years to get here?”

“Let’s say they are about three light-years away now, though they appear four light-years away due to the light speed lag.  They would have slowed from 46% the speed of light to only about a quarter c.”

Nathan shook his head with a grin.  “You’ve put a lot of thought into this, sir.  Okay.  Am I assuming we have a magic space drive or current technology only?”

“I am not aware of any magic space drive.  Yet.”

“Fine.  With current technology, there’s virtually no chance we can field a mission to the enemy within the next 22 years.  Chemical rockets have high thrust, but are too bulky and have abysmal specific impulse.  Ion engines approach the right efficiency and specific impulse but lack any real thrust or payload capability, and they have the same problem as chemical rockets with endurance.  They simply can’t carry enough reaction mass.

“It’s the rocket equation.  Since you have to carry your fuel with you, and you have to accelerate your own reaction mass at the same time as you boost your payload, there’s an upper limit to the velocities you can achieve, not to mention that 99% of your ship will be fuel and sacrificial mass.  A laser driven lightsail or an Orion-style nuclear pulse detonation engine might work, but that’s still theoretical—not exactly current technology.  The furthest we might get within the next 22 years with current rockets, ion engines, gravity assists, et cetera, would be the Kuiper Belt and that’s practically in our own back yard.”

“I would agree, unfortunately.  So that’s out.”

Nathan shook a finger at him.  “No, sir, not out.  It’s just of limited utility, but information is information, even if it’s of the last-minute variety.  I would send a spy probe out yesterday with current technology and hope I come up with something better within the next couple of decades.  At the same time, I’d invest in some at-home recon.  Maybe I could get some time on the Earth based telescope networks, or accelerate development of the SSBA.  That baby would make something a couple of light-years away look like something orbiting Mars from an Earth-based scope.”  The SSBA, or Solar System Baseline Array, was a system of space-based optical telescopes which would be orbiting throughout the entire solar system in a few years.  By spreading the telescopes out and combining their images electronically through interferometry, they would become a virtual telescope with a primary lens the width of the solar system from Earth to Saturn.  It would be immeasurably powerful, capable of resolving terrestrial planets in nearby solar systems with ease.  It was also obscenely expensive, delayed and opposed as a boondoggle at every turn.

Gordon Lee took to his feet as well.  There was a strange sparkle in his eyes as he began to get caught up in Nathan’s speculations.  “Yes.  All right, we send out probes and we use the most powerful, most capable telescopes we can.  What next?”

“Next depends on the recon.  Everything depends upon what we know or don’t know about the aliens.  It’s impossible to say much now, without any observational data, but there are a few assumptions we can make about the enemy just because of the way it moves.”

“Go on.”

“They’re traveling here in a rocket—a magic rocket with an inexhaustible source of fuel, but a rocket nonetheless.  That would seem to indicate that they don’t have any sort of warp drive or wormhole jumps or reactionless, inertialess, Roswell alien sort of spaceships.  Right?”

Lee tipped back his beer and fetched another pair of bottles as he actually seemed to consider Nathan’s supposition.  Nathan finished his own beer and took the fresh bottle the other man held out to him.  Eventually, Lee nodded.  “I think you may have over-extended your assumptions, but I’ll go along with it.”

“Okay.  They have high technology but not supernatural, magical technology.  They are bound by inertia the same as we are, so the simplest way to attack them would be to put something in their way.  A kinetic missile strike would ruin their day, and given the velocities involved, it would be fairly simple to achieve.  On the same mission that sends out the recon probe, you can seed the outer solar system with mines.  When the big bad aliens show up, the mines rocket toward them and no more invasion.”

Lee sat down, looking vaguely disappointed.  “Mr. Kelley, these aliens have come here from nearly twenty light-years away and have traveled at nearly half the speed of light.  Given the amount of damage a single grain of sand could do at those velocities, not to mention the radiation involved, don’t you think the aliens would have come up with some method of clearing their path?  I doubt simply throwing a rock in their way to trip them up would be the best defense for the planet.”

Nathan nodded slowly and grinned in a way that was more adversarial than friendly.  He would either confirm or end his chances at this mysterious job, depending upon how he responded to Lee’s criticism.  Agree or disagree with the boss, both choices were dangerous.  “Sir, I said that was the simplest method of attack, not the best.  And while they probably do have some sort of deflector shield or clearance beam or relativistic dust-buster, it’s a completely different proposition to deflect a coordinated strike with hardened, militarized weapons than it is to annihilate some micrometeors.”

Lee’s eyes had narrowed and his mouth was set in a grim line.  “Very well.”

“The best ways to defeat any defensive system is with depth, diversity, mass, and maneuver.  Depth is layers upon layers of weapons.  Diversity is in types of weapons.  You hit them with every type of attack that might even remotely be effective:  lasers, nukes, bomb-pumped lasers, particle beams, kinetic strikes, logic bombs, and more.  Hell, if you can put a rocket underneath the kitchen sink, you use that too.

“Mass is the density of attacks in each layer.  Every defense has a threshold, a limit to what it can take.  You give me enough of the right kind of weapons, I can storm the gates of heaven.  And maneuver, well, we’ve already said they’re bound by inertia.  If you make your weapons agile enough, set them up on just the right bearing, at just the right offset and velocity, throw in some countermeasures perhaps, then you can slip past almost any defense short of a force field.  And defeating a force field just brings us back to mass.  You want to defeat an alien invasion, that’s how you do it.”

“And what is the most important part of our defensive plan?”  Lee’s voice was quiet, almost too quiet to hear, and absolutely too quiet to determine if his hush was in disappointment or admiration.

“Time and distance.  The most important thing, sir, is to keep the aliens from reaching Earth.  If they make it to the planet, it’s all over.  All they have to do is turn the exhaust of their magic space drive toward us and the planet would be roasted like a marshmallow.  Or, if they favor things up close and personal, put them in orbit at the top of our deep gravity well so the energy balance is on their side.  They can just rain down strike after strike until not even the cockroaches are left.”

Lee just stared at him.  Nathan took a long drink, nervously finishing most of the bottle.  When he looked back down, Gordon Lee was walking away.  Nathan grimaced and said under his breath, “Damn it.”

Lee came back with a tablet computer in his hand and gave it over to Nathan.  It automatically scrolled through a series of astronomy slides.  The first picture was of a particular night sky.  An unfamiliar constellation drew itself around a set of stars, and a number of Greek symbols popped up next to the most prominent stars.

“Mr. Kelley, what you are looking at is the constellation Pavo, the Peacock.  It’s only visible in the southern hemisphere.  The fourth brightest star in Pavo is Delta Pavonis, and it’s a G-type star much like our own.  In fact, of all the nearby stars capable of supporting life as we know it, Delta Pavonis has long been considered one of the best candidates for an alien intelligence, even though it is a bit old and in its declining years.  All the other G-type yellow suns in our vicinity are binary pairs, and it is thought that the interactions of the sister stars would interrupt the regular orbits and seasons of a terrestrial planet, making life almost impossible.  But Delta Pavonis is alone in the heavens, 19.9 light-years away, and free to develop life, much as we did.”

“Why are you telling me this, sir?”

Lee tapped the tablet’s screen and another series of slides popped up.  It focused in on the fuzzy yellow circle/dot of Delta Pavonis.  In the next slide, a blue pinprick dominated one side of the star.  In successive slides the pinprick drifted across the face of the yellow dot and back again, getting ever brighter and wider, and drifting further and further over the dot in the background.

“In the 1930’s, radio was truly born.  It went from a laboratory and military oddity to a worldwide tool, a tool which would help drive empires and wars, and a tool which cast out its beacon into the night sky.  Much of it was of too low a power to penetrate the ionosphere in any sort of intelligible fashion, but it is apparent that something did.  Whatever the reason, nineteen point nine years later, someone around Delta Pavonis noticed us, and they sent out a magic rocket without any sort of warning or courtesy call to the people they’re coming to visit.  Forty three years later, they turned around and began to slow down, because they intend on staying a while, it seems.  Ten years after that, in 2023, I saw it and began my preparations.  And now, here we are, with uninvited guests en route, and no way to turn them back at the door.”

Nathan had no idea what to say.  Some of the rumors he had heard about Lee now seemed to be a little closer to fact.  He sat the tablet down upon the table and stared at the garden.  “So, that question wasn’t a zinger.  It was an actual question.”

“It was a question and a job offer, Mr. Kelley.  I’ve spent the last ten years planting the seeds of our defense.  Not including a few notable exceptions, people able to see beyond their own preconceived notions of what’s out there, I’ve done it all myself.  Because of the nature of this new truth, it unfortunately seems like almost all of the people I can convince I’m serious are the crackpots who have the least to offer me.  And don’t even ask about government support.”

Nathan turned back to Lee, whose eyes burned intensely, but whether it was in madness or determination, Nathan could not tell.  “Okay.  I won’t ask.”

“I’ve sown the seeds, but now I need someone to reap the results.  I don’t ask that you believe me, or believe the data, but I do ask that you approach this task seriously.  You have a unique skill set.  I’ve read military sci-fi, but I need someone with some actual tactical and strategic skills to
do
military sci-fi, to make the possibilities real.  I need you to lead my Special Projects branch, consolidating the results of the various research initiatives I’ve funded in order to develop a defense of the planet.  I need an engineer, a manager, a leader, and a seasoned, bloodied naval warrior.  You’re all of that in a single package.”

Nathan finished his beer, but his mouth was still bone-dry.  He turned away from Lee and began pacing again, running a hand through his hair.  “When you say ‘bloodied naval warrior’, I assume you’re referring to the
Rivero
.”

“Yes.”

“I
sank
the
Rivero
, Mr. Lee!”

“The enemy sank your ship, Nathan, and two other ships that day as well.  You were all sucker punched, but out of every battle of that day, you were the only one to sink your attackers in return.  You defeated the enemy and blunted the ferocity of his attack, saving over a hundred and fifty members of your crew.”