LAST SMALL STEP

 

STEPHEN BAXTER

 

AS WE CROSSED the orbit of Neptune, heading outward, I woke from coldsleep with my head full of the mental state of our quarry, Stavros Gershon. And with the words of Lemuel Gulliver in my ears.

This lodestone is under the care of certain astronomers, who, from time to time, give it such positions as the monarch directs. They spend the greatest part of their lives in observing the celestial bodies, which they do by the assistance of glasses, far excelling ours in goodness. For, although their largest telescopes do not exceed three feet, they magnify much more than those of a hundred with us, and show the stars with greater clearness. This advantage has enabled them to extend their discoveries much further than our astronomers in Europe; for they have made a catalogue of ten thousand fixed stars, whereas the largest of ours do not contain above one third part of that number...

“Win. Winifred. Win Chambers. Are you with me yet?”

Gulliver was paused. Another voice. A face, looming over mine.

“Joe Salo.”

“You got it,” he said. “Well done.”

“You need a shave.”

“I’ve been all alone in this tub for a month, aside from you in your coffin. Facial hair wasn’t a priority.”

I tried to sit up. The coldsleep pod, my ‘coffin’, was smart. It tipped me up with a whir, and in zero gravity I floated comfortably, my loose gown drifting around. I was in a small, boxy cabin, the walls plastered with smart screens, a couple of couches set before the control stations. A small galley, a door that led to the bathrooms and the cupboards we slept in. Two coldsleep pods. Home from home, for this two-year flight.

Salo was watching me. “You know where you are, right? We’ve had no problems. We got through the acceleration phase and we’re cruising. Once you’re nominal, I’ll duck back into coldsleep myself. You’re up for another month to make sure I didn’t miss anything. And then we’ll snooze side by side until month twenty-one—”

“I know I’m on the Malenfant.” The name of your ship is a standard post-coldsleep memory check.

“Full name?”

“Reid Malenfant, Common Heritage Deep Space Vessel 2248-9D.” A veteran of the Earth-Mars run, the ship was older than its Heritage registration date. Most machines on Earth, and in human space, were decades old at least. I said dryly, “I even remember that the ship was named for the loser who crashed a space shuttle booster in...”

“2019. The booster was called the Constitution. And hey, that loser risked his life to save Cape Canaveral.”

I concentrated. “Whereas we are in pursuit of a character called Stavros Gershon, who took a ship called...”

“Last Small Step. Like the programme. Very unoriginal.”

“Right. Out to a dwarf planet at two hundred AU.” Two hundred astronomical units, two hundred times as far as Earth is from the Sun. A rogue world maybe, passing through that sparse, diffuse realm of minor planets and other debris between the Kuiper Belt and the Oort Cloud. “So that Gershon can do the footprint and flags thing, first on a new world. What I don’t know is exactly where we are now.”

That was when I found out the Malenfant was crossing the orbit of Neptune. A mere hundred days out from Earth. Twenty more months before we would reach our destination.

“Shit. Is that all?”

But I had known the mission parameters before we set off. The Malenfant was optimised for short-haul journeys in the inner solar system: a few days from Earth to Mars, if the relative orbital positions were right. It could cross a distance two hundred times further, but it would take two years to get us there. However, it was all we had. Two hundred and fifty years after Reid Malenfant’s moment of glory, mankind had no need for more powerful craft, having turned its back on human space travel almost completely.

Hence the Last Small Step programme, in fact.

Last Small Step. Of course everybody knows Neil Armstrong’s line as he became the first human to walk on another world: “That’s one small step for a man...” Even if, I had learned, 40 percent of people who consult the Answerers about it think that Armstrong was the one who went to the Americas on the Santa Maria. When the Pull Back to Earth movement cut in—when humanity as a whole decided to abandon space, retreat to a slowly healing Earth, and leave the mess we had made on Mars, Venus and the Moon to the AIs—protests had been spiked by the establishment of the Last Small Step programme. It was a kind of compensation. The idea was to allow a last wave of explorers to follow in Armstrong’s footsteps, to send out one last human mission to each remaining virgin “world” in the Solar System—that is, each planet, minor planet or moon large enough to be compacted into a spherical shape—and, wherever possible, to land there, even just once, to plant a flag and a plaque, and come home again. No harm done to the target world, in the spirit of our age. Just to say we’d been there before we went home for good.

The trouble was, Stavros Gershon seemed intent on breaking the rules. Hence our mission.

Salo handed me a flask. “Drink this.”

A soupy glop that was highly nutritious, and full of helpful nanotech to counteract such extended-spaceflight problems as a loss of bone mass, a lousy fluid balance and a cumulative radiation load. It tasted like cold vomit.

Salo said, “So you do remember our mission.”

I grunted. “Yup.” As scientists, low-grade field workers, we’d done a handful of space missions together, mostly chasing near-Earth asteroids in ships like this.

I was forty-one, Joe thirty-something. We’d spent months in cramped cabins together. We both had strong families back home. We got along well enough.

Usually.

Anyhow, now I pushed down my reflexive irritation at his probing; he had to ask these post-coldsleep questions. “So when Gershon took off, heading beyond the Kuiper Belt—”

“Unauthorised.”

“We volunteered to do the chasing.”

“Right. His destination was recognised as a valid Last Small Step target. The last of all, actually. Well, probably.”

After the Last Small Step programme had been established, it had proven popular. The available targets, mostly minor worlds in the Kuiper Belt and Oort Cloud, had been used up surprisingly quickly, even out to a thousand astronomical units or more. And Gershon’s target was believed to be, maybe, one of the last of all. A ball of ice and rock, probably, a little smaller than Ceres, with a couple of even smaller moons.

Salo prompted, “And we are after Gershon because—”

“Planetary protection. He’s been threatening to do more than take a photograph at his target. Mining, maybe. We were appointed Prefects pro-tem, with the authority to go after him, and grab him, and clean up as necessary.”

Salo nodded. “If he does go beyond the Last Small Step parameters.”

“Stavros Gershon,” I said, my frozen brain slowly thawing, “believes he is descended from one of the first on Mars, so carrying on the family tradition. And his target—no name, I can never remember the catalogue number—”

“Actually, it has a name now. Gershon gave it one—or, he says, he rediscovered it.”

Which bit of oddness reminded me of what I’d been hearing when I woke up. “Why were you reading Gulliver’s Travels?”

He looked impressed. “Well recognised. Part III, chapter III. But it wasn’t me reading. It was a transmission from Gershon, on the Last Small Step. From beginning, unpause.”

On a wall screen, a smiling face appeared, framed by a standard lightweight pressure suit hood. A ship’s cabin. “Hello. I am Stavros Gershon...”

I sipped my soup, and wondered why I didn’t need to pee, and stared.

Stavros Gershon looked maybe fifty years old. He didn’t much resemble his famous ancestor, but then after the huge mixing of mankind during the decades of the Chaos, few of us looked much like our great-grandparents, probably. I had to admit his ship, the clunkily named Last Small Step, looked spacious, even comfortable, compared to our bare-bones Malenfant. Gershon must have been donated a lot of stipends by a lot of supporters.

“And I suppose, as I approach the minor planet Voga, that you are wondering why I am reading to you from a text first published in 1726, over five hundred and forty years ago...”

“Pause,” I said. “Voga?”

“I checked out the name,” Salo said. “Bounced it back to the Archives on Earth. It’s pretty obscure—a legend that may have its origin in fiction, even...”

“What legend?”

“Of a planet made of gold.”

I stared at him, and at Gershon. “Gold? That’s... insane.”

“Probably. But there’s a logic to it. I think.”

I was thinking too, but very slowly. “And it has something to do with Gulliver’s Travels?”

“You got it. Unpause.”

Gershon rattled through the passage I’d heard earlier, and read us some more: “They (that is, the astronomers of the flying island of Laputa) have likewise discovered two lesser stars, or satellites, which revolve about Mars; whereof the innermost is distant from the centre of the primary planet exactly three of his diameters, and the outermost, five; the former revolves in the space of ten hours, and the latter in twenty-one and a half; so that the squares of their periodical times are very near in the same proportion with the cubes of their distance from the centre of Mars; which evidently shows them to be governed by the same law of gravitation that influences the other heavenly bodies. They have observed ninety-three different comets, and settled their periods with great exactness...”

“And so on.” Gershon grinned into his monitor. “You see? It’s all in there. The clues to the treasure. Sitting in plain sight for five hundred years.”

“And you’re the genius who figured it out,” Salo muttered. “What treasure, though?”

I studied Gershon’s face. I’m more interested in people than Joe—an age difference thing, maybe. Gershon was grinning, but there was a kind of desperation there, I thought. As if he didn’t fully believe his own logic, as if there was something deeper driving him. Which is probably true of all of us. What are you doing out there, Gershon? What treasure? And what do you really want?

Meanwhile, memories were reassembling in my reluctantly waking brain like the pieces of a puzzle. Thud. Thud. “And this was why we were sent after him, in such a rush. Because, whatever the logic, if he gets there and starts taking samples that are more than scrapings for science, if he starts prospecting, or even mining—”

“It’s against Common Heritage law, and we need to bring him back, clean it up.”

Thud. “Right. And that’s why we aren’t going home again any time soon.”

“Correct. You remember there wasn’t the time to upgrade this Mars-run taxi cab to get us there and back. We haven’t the fuel. So we go to this ‘Voga’, deal with Gershon, and the three of us go into coldsleep until we are followed by a more capable ship in a few years.”

Thud.

“Shit,” I said, putting a lot of heft into the word.

“Seconded. So you want to get out of that coffin and get to work? The sooner I get back into coldsleep, the sooner this mission will be over for me...”

 

 

I STAYED AWAKE for a month, alone in trans-Neptunian space. That was the fourth month of our twenty-four-month mission.

Then we both slept away much of the rest of the featureless journey. All this was routine. You rotate in and out of coldsleep to save consumables and your own sanity, and focus on the interesting bits.

I was the first to be woken the next time, at the start of our twenty-first month—by which time we were just thirty-some astronomical units or so out from the target. From Voga, planet of gold.

I spent that twenty-first month checking out stuff, and puzzling over Gulliver’s Travels.

I went over the ship from bow to stern, even though I had every faith in our craft, a tried and trusted development of centuries-old technologies. The Reid Malenfant was like an arrow, with a fat blade and sprawling fletches, and a bunch of balloons stuck to the shaft. The “blade” was our living quarters, a roughly conical hab module containing us, our coldsleep pods, and assorted junk, that sat on top of a service module cum lander, which contained the infrastructure of the closed-loop life support system that kept us alive, as well as a propulsion stage and other essentials.

The arrow’s shaft contained our interplanetary propulsion engine, technically known as a magnetoplasma rocket. Our propellant was hydrogen, stored as a liquid in those balloon tanks along the shaft. We had a compact fusion reactor whose energies ionised the hydrogen to plasma using powerful radio blasts—the fletches at the rear of the arrow were radiator panels, dumping waste heat from this process—and the plasma, bearing an electrical charge, was then grabbed by a magnetic field and hurled out the back. The system was mature technology and ran smoothly, and gave us our cruise velocity of five hundred kilometres a second.

As I said, such a ship, with such a performance, purring along, would get you to Mars and back in a few days or weeks. Even the Jovian system, five astronomical units from the Sun, was within reasonably easy reach. But it would take us two years to get to Voga. To get there in a more sensible time, we would have needed a much more powerful drive—a propellant driven directly by a fusion reaction, maybe, or even by matter-antimatter annihilation. Once we had been developing such drives, but progress stalled when the Chaos came, and industry had to prioritise more urgent needs such as food printers—indeed the whole complex of industrial civilisation came close to collapsing altogether. When we came out of that, the will was gone. And that was why we were crawling out to the Kuiper Belt in an Earth-Mars transport.

And hence our enforced layover at Voga, once we got there. Our low exhaust velocity gave us significant problems with fuel loads. To slow down our twenty-six-tonne dry mass from our cruise speed would take nearly twice as much mass in hydrogen fuel. And to accelerate our dry mass plus our deceleration fuel up to our cruise velocity in the first place had taken nearly twice that total in fuel, again. (Talk to an Answerer about the rocket equation.) So we had left Earth orbit with a mighty load of a hundred and seventy tonnes of hydrogen fuel.

But it could have been worse. If we had tried to ship along enough fuel for the return trip too, the fuel load would have been something over a thousand tonnes. You could put together such a mission, though the structural challenge alone was monumental: where would you hang all those balloon tanks? And indeed, a mission was being assembled right now back at Earth, to bring us home. But such was the urgency to get hold of Stavros Gershon before he did any harm out at Voga that we had had to be fired off on this one-way mission, before the retrieval option could be designed, let alone assembled.

Look, I’m not complaining.

While on the mission, and especially with our temporary status as Prefects, Joe and I had to follow certain protocols. We were volunteers, of course; we didn’t have to be there. You get your Heritage stipend whatever you do, even nothing at all. I wouldn’t have been there at all if I hadn’t basically enjoyed the routine of long-haul spaceflight.

Anyhow, I told myself, the first ocean-going ships to reach the Arctic and Antarctic had used sails. They’d been inadequate for their task too, but their crews had gone regardless. And they had to overwinter, just as we would, in a sense.

For sure, we’d have an anecdote to impress our grandkids.

The work I had to do on the ship was routine. Similarly, my personal needs for sleep, food, exercise were easily met. Eating alone always bores me.

Gulliver’s Travels and Gershon’s enigmatic remarks were a lot more fun to work on. I have always been a cerebral, solitary type. Lock me in a room with a good mystery to solve, a scientific puzzle maybe, and I was happy—and that was pretty much the situation I had landed in here.

And there was a human puzzle too, which would always attract me more than Joe. The puzzle being, of course, Stavros Gershon’s true motivation.

Most Last Small Step voyagers were happy to stick to the rules. They wanted their moment of fame—and it was enduring fame indeed, as once you are the first somewhere, you will be remembered as the first for all time. There were collector types who had been to as many worlds as they could. There had been a few highly publicised races. And so on.

But they stuck to the rules, which fitted the paradigm of our times. You went down, took your photographs, cleaned up, went home, leaving no more pollution than a flag. Not Gershon, though. I looked again at his message loop, at the need, yes, the desperation in his eyes. There was something more he wanted, and he wanted it badly. The trouble was, he wasn’t saying what that was, not yet.

So, a puzzle. I admit that when I had finally figured it out—or at least the Gulliver stuff, and most but not all of it, as it turned out—I couldn’t wait, and woke up Salo a whole day early to tell him about it.

 

 

“YOU SEE, I don’t think Swift was describing Mars’s moons at all. And I believe that’s the way Gershon is thinking too. You seem surprisingly grumpy, Joe.”

Salo, still in his soft sleepsuit, a survival blanket around his shoulders, sipping a tumbler of nutritious, nano-infested glop, glowered at me. “I wonder why,” he said. “Get on with it. Swift says they’re the satellites of Mars, doesn’t he? He wrote that book in...”

“1726.”

“And Mars’s two moons weren’t actually discovered until...”

“1877. By Asaph Hall—”

“I don’t care. I thought Swift had always been praised for a lucky guess, at least.”

“Well, I’ve been looking into that.”

“You would.”

“He probably followed a kind of mathematical logic. It was believed that Earth had one moon, and Jupiter four: the Galileans, all that could be seen with the telescopes of the time. So it was logical, in an orderly universe, for Mars, in between Earth and Jupiter, to have two moons. One, two, four.”

“But didn’t he get the periods about right too?”

“Not a bad guess. He has the inner moon orbit Mars in ten hours, whereas Phobos actually takes just under eight. The outer moon took twenty-one and a half hours, whereas Deimos takes thirty hours. The right order of magnitude. He got the distances from Mars more wrong, though: over twice the true distance for Phobos, nearly 50 percent too high for Deimos. Not that he used those names.”

“Will you ever get to a point, Chambers?”

“But,” I went on doggedly, “what Swift did get right was Kepler’s Law of planetary orbits. He understood Newton’s gravitation, you see. So the square of the orbital period of each of his moons is proportional to the cube of the radius of the orbit, just as it should be—”

“He was describing a plausible system, then.”

“Yes. But just not Mars, not the Mars as we know it. And the information he gives us is... selective. Which makes me think he was describing something else. Listen again.” I pulled up Swift’s words.

Satellites... whereof the innermost is distant from the centre of the primary planet exactly three of his diameters, and the outermost, five; the former revolves in the space of ten hours, and the latter in twenty-one and a half...

“Those are the only numbers he gives. He doesn’t give masses, or absolute sizes—such as the diameter of Mars, for instance. He just gives the timings, and the relative distances of the moons’ orbits and the planet. Which, if you think about it, is precisely the data you’d get from a basic telescopic observation, without any estimate of your absolute distance from the object. Just the size of one element, compared to another.”

He was waking up; he plodded after my conclusion slowly. “So are you saying that Swift is describing another body? Another system, not Mars and its moons? Something that was actually seen by some astronomer before 1726?”

“That’s possible, isn’t it? If such a system had existed, and was close enough—”

“But no such system does exist, or we’d see it now... Ah.”

I grinned. “You’re getting there. Suppose a rogue planet came wandering through the solar system. Sometime in the decades before Swift, when the followers of Galileo were mapping the sky. A one and only pass. You might see the planet, see its moons, measure times and relative distances. No time to get a fix on the true distance, or the diameter of this fake Mars, before it passed back into the dark, not with the technology of the time. Maybe the result was never published properly; the observation couldn’t be repeated, after all—and at the time there were a lot of unreliable sightings, of moons of Venus, a second Mercury...”

“It couldn’t have been too massive, or it would have perturbed the other planets.”

I shrugged. “Small and close would be visible but harmless.”

He nodded. “And so Swift gets hold of this sighting and weaves it into his fiction. He imagines Mars is like this... wanderer. Because, and it’s just a coincidence, the wanderer has two moons, as he thinks Mars must have.” He looked at me. “But now, here we are chasing Stavros Gershon out to some object two hundred AU from the Sun...” He slapped the side of his head. “My mental arithmetic is stuck. Curse you, sleep pod.”

“I worked it out,” I said evenly. “An object with perihelion close to the Sun, aphelion two hundred AU out, would have an orbital period of about a thousand years.”

He nodded. “It’s five hundred years since Swift. So this object, if it exists—”

“Should now be out near aphelion, its furthest distance from the Sun. Two hundred AU out. Just where Gershon has found his Voga.”

He stared at me. “I’d congratulate you on your logic, but I’m afraid I’ll throw up again. Okay, I can just about buy that. But what about all this crap about a golden world? All in Swift too, right?”

“Yes. If you look hard enough.” But I was on shakier ground, and I hurried on. “Look—I said Swift couldn’t give us the absolute sizes of his fake Mars and its moons’ orbits. But we have the orbit timings, and their relative sizes, scaled against the planet’s diameter. And from that you can work out one more number. The planet’s density. Not its mass, its density. Mass per unit volume...”

He was still dopy enough that I had to walk him through the logic.

This time it was about Newton’s theory of gravity, which built on Kepler’s observations. Newton predicted that the period of a moon’s orbit, squared, is proportional to the orbit’s radius, cubed—that was Kepler’s Law—but also inversely proportional to the planet’s mass. In this case the orbit radius was given in terms of multiples of the planet’s own radius—and the cube of that is proportional to the planet’s volume.

So in Newton’s equation you know the period, and you have the planet’s mass divided by the volume, which is its density...

You don’t have to follow all that. Working through the math is easier, actually. Go ask an Answerer. Salo didn’t follow it all, not at that moment. But he got the essence: the denser the central planet, the faster those orbiting moons would have to whip around it. And—

“And so we know the density of this Voga. Right?”

I just grinned.

“Well, tell me!”

“Comes out at twenty-four tonnes per cubic metre.”

He was still fuzzy. He growled, “So? Water is around one tonne per cubic metre. Iron is...”

“Nine tonnes per cubic metre.”

“Oh. Which is what rocky planets are mostly made of.”

“Right. Earth’s average density, for instance, is five tonnes per cubic metre. Iron and rock. Whereas gold is nineteen tonnes per cubic metre. Platinum twenty-one tonnes. Look, you can see that Gershon is onto something here. Something exotic.”

He rubbed his face. “Yeah, but what? It’s been a long time since Gulliver. We must know more about this object by now.”

“Sure. Or we wouldn’t be chasing Gershon out here. It was spotted visually by some deep space probe, decades ago. Just another Kuiper object, a sphere, away from the bulk of the Belt. It’s less than a thousand kilometres across. Which gives it the mass of Pluto, by the way, but it’s so massive it has a respectable gravity—about the same as Mars.”

He thought about that. “An atmosphere, then? It will be damned cold out there, but—”

“It’s possible. Gershon seems to have found it in a catalogue of Last Small Step targets. It started looking like the last available target of all, which must have attracted his interest. And then he spotted the anomalies, and somehow made the connection with Swift— ”

“No wonder he went out there. And he has found something exotic, from what you say. But maybe not exotic in the way he’s hoping.”

“What, then?”

“How should I know? I’m barely conscious. And now—”

And now it was time for him to throw up, again.

Turned out he was right, though, in that first reaction. When we finally got to Voga, it was certainly exotic.

But nobody calls it Voga anymore.

 

 

FROM LOW ORBIT, it was a ball of rock wrapped in a murky atmosphere under which glistened shallow lakes of some kind of fluid. And it did indeed have two moons, two splinters of rock and ice even less impressive than their parent. All this illuminated in the point light of a Sun giving off only one forty-thousandth its brilliance in Earth’s sky.

We ran scans. We quickly found that the moons’ orbits closely matched Swift’s descriptions. And Voga’s density was just as I had calculated.

But Voga wasn’t made of gold. Our neutrino scans revealed it was pretty much like Earth, in fact, an iron core wrapped in a layer of silicate rocks. Just iron and rock, but very densely packed.

And, from space, it was dull, all but featureless: no mountain ranges, no ocean basins. Very few impact craters, which Salo said was a consequence of a geologically active surface; features like craters wouldn’t last.

In fact, the only feature on its surface to which the human eye was drawn was a spacecraft, or anyhow its hab-lander module, pretty much similar to ours though larger, and neatly set down close to one pole. We had already spotted Gershon’s interplanetary propulsion unit in high orbit around the planet. Beside the lander, our telescopes revealed, was a trail of footprints in what looked like stiff mud, and a single flag. The Stars and Stripes: flag of a nation that no longer existed, but the flag that had been set on the Moon by Armstrong, and no doubt on Mars by Ralph Gershon, so the Stars and Stripes it had to be.

There was no immediate sign of Gershon himself. We did download a message from his lander, running on a loop.

Before we watched the message, we ran through a couple of orbits, and got used to the journey being over, and just took in what we saw.

“A few things strike me as odd,” I said at length.

“Go on,” Salo said.

“All we see down there is iron and silicate rock. The neutrino scans show traces of more exotic substances, heavier metals—there is some gold down there, but no more than you could obtain by mining on Earth. So how come it’s so dense? We’re measuring the mass directly now; the figures don’t lie.”

“I’m developing a theory,” Salo said slowly. “Maybe the formation of this rock ball was—unusual. Maybe it didn’t form the way Earth did, coalescing out of a Sun-centred cloud of dust and ice—with a few spectacular collisions along the way.

“Consider an ice giant planet. Uranus, say. Mostly a big ball of gas. But at its heart it has a core, which is like a planet in itself—a rocky planet, like Earth, a ball of iron and rock and maybe some water. An Earth, buried deep inside a heavy atmosphere. In the case of Uranus, the core mass is 60 percent of Earth, the radius 60 percent—”

I worked the numbers quickly. “Density of about fifteen tonnes per cubic metre. Much more than the Earth. I get the idea. And if somehow you could strip away the outer atmosphere—”

“We know that happens,” he said. “We’ve seen it in other systems, when some giant exoplanet migrates in too close to its star, and its outer layers are evaporated away by the heat until the core is exposed. You would think that the core, once it was released from that crushing weight, would just explode. But—I’ve been looking it up—in theory, if the atmospheric loss is slow and the core has time to adjust, if the core has the right composition, if something called its finite-state incompressibility is tuned just right—”

“The core can survive?”

“Right. For a billion years, maybe. A very slow explosion... This is a pretty small specimen. But maybe it’s a fragment of some larger object. Planetary formation is a big, messy puzzle.”

“I’m surprised to see it has seas.” I glanced down at the surface below, flat and glistening, hazed with cloud or mist—and, here and there, what looked like mud pools, bubbling. “Puddles, anyhow. And what looks like heat escaping.”

“Yeah. There’s actually some volcanism up near the poles. Big flat pools of lava, lots of gases venting. The interior must be active, a lot of geothermal heat to lose. And it’s outgassing enough to create an atmosphere. I can see carbon dioxide, methane, ammonia in the lower air. Layers of clouds at different levels. Water too—even puddles of it on the surface, as you say.”

I glanced at the pinprick Sun. “Liquid water, though. Even if the planet is leaking inner heat—we are a long way from warm here.”

He tapped the screen. “I think Voga has an extended atmosphere. Hydrogen. Hard for us to see, but a big fat envelope, enough to exert some pressure at the surface, act as a greenhouse, and trap that leaked inner heat. Given time, and enough hydrogen, the world could become as warm as you like. Maybe the planet collected the hydrogen as it migrated out of the solar system—no, dummy, that can’t be right; it would lose the envelope every time it jaunted back into the inner system, as in Swift’s day. And all that volcanic carbon dioxide must react with the hydrogen layer too...” He started to sound excited, his mind working quickly. “So something must be generating fresh hydrogen. And if that’s so—”

“Yes?”

“Let me think about it.” He glanced at me. “First things first. We need to deal with Gershon. Presumably the most disappointed man in the solar system. Let’s hear his message.” He tapped a screen.

And there was Stavros Gershon.

Yes, I was expecting disappointment. Even desperation. After all, whatever its true nature, Voga hadn’t lived up to his dreams.

But he didn’t look disappointed to me.

Gershon stood in a pressure suit, on the surface of Voga, with the Stars and Stripes beside him, and his ship set down neatly on the surface beyond. He was grinning through his visor.

And he had what looked like explosive, strapped by an elasticated belt around his waist.

Salo and I shared a glance. Anxiety gnawed my stomach.

Gershon said now, “Hi, guys. You two in the Malenfant, who trailed me out here, and whoever follows after. I appreciate your efforts, believe me. But you’re too late. This is a recording, and that’s all you’ll ever get from me.

“Look—I achieved what I came here for. Primarily, anyhow. My own footprints and flags moment, yeah. And I was right about Swift and the anomalous density of this boulder, right? I confirmed this place exists, and established its true nature. Some achievement, in interplanetary geology, and in the history of literature. Even if I didn’t get it quite right.

“I never thought Voga would be gold! That was just a headline. I did hope it was going to be a mother lode of—something special. Heavy, exotic elements. Radioactive, maybe. A resource lode on the edge of the Solar System, which might have jolted us out of this Pull Back to Earth crap, if not now, some day. Just knowing it was here, on the edge of interstellar space, might have drawn us back... Well. It wasn’t to be.

“But there is something else I can do, I figure. Another way I can make this place attractive to future visitors.”

Salo growled, “And make sure you are remembered, and not as a failure...”

Gershon’s gloved right hand moved to his belt. I sensed Salo tensing up beside me.

“So this isn’t a fuel lode, but it’s a world, right? A world of rock and water, and carbon and oxygen. A world that’s not so terribly unlike ours—maybe as Earth was when it was much younger—but a world without life. And maybe that’s something I can change, right here, right now.” His right hand still on his belt, with his left hand he dug into a pouch and produced a book, an old-fashioned paper volume. “I have here a copy of the Holy Bible, King James version.”

Salo frowned. “What’s that?”

“Archaic religious text. Judaeo-Christian, I think. All about how God created the Earth, and everything that lives on it.”

“Oh, crap.”

Gershon said, “I know the old religions are out of favour now, but—well, I’m pretty much out of favour myself, aren’t I? So.” Now he raised the Bible in his left hand. “Genesis, Chapter One, Verse 10: ‘And God called the dry land Earth; and the gathering together of the waters called the Seas, and God saw that it was good.’”

Salo growled, “No, no, you idiot. I know what you’re going to do. You’re going to blow yourself up, right? But you don’t get it.”

“‘And God said, Let the earth bring forth grass, the herb yielding seed, and the fruit tree yielding fruit after his kind, whose seed is in itself, upon the earth; and it was so...’”

Salo muttered, “And this is a recording. We’re too late, too late.”

“Too late for what? To save his life?”

“No! To save the damn planet. Because there is already life here. Don’t you see?”

I didn’t, not then.

And neither had Gershon, evidently. Because he finished his reading, closed up the Bible in his left hand, and closed his right hand over a control at his belt.

“‘And God saw that it was good.’” He smiled.

All we saw after that was static.

 

 

I GUESS I’LL never fully understand Gershon’s motivation.

He had no family he was close to, back home. A network of friends whose stipends had funded his mission, I supposed. Or acolytes, folk he dazzled.

Gershon wanted to be remembered, I guess. And not just as a logically reconstructed trace in an Archive. In a world without heroes, Gershon had grown up in the shadow of his Mars-walking ancestor Ralph, who was an authentic hero, and would never be forgotten. Whereas Stavros had no kids, no enduring achievement on Earth. And he was fifty, a tipping point in anybody’s life. He wanted to be remembered, and not just in a catalogue of grinning Last Small Step adventurers. He wanted more. He wanted to change the world—a world, anyhow.

I’m no romantic. A child of my more settled times, I guess. But something in me was touched by the wistfulness of his gesture, as if we were remembering a common childhood. Or maybe it was all just a sublimated fear of death.

In any case our world just doesn’t work like that anymore. We don’t need that kind of hero. We won’t allow it.

When I reran the recording, I saw that the detonation had blown down Gershon’s flag.

And, just before the detonation itself, that Gershon had been crying.

 

 

WE BROKE INTO our coffee hoard. That’s how bad we felt.

But when I had time to think it all over, I had a glimmer of hope. Not for Voga, or Gershon. For us.

After we had calmed down for an hour or so, I broke the ice. “You were a couple of steps ahead of me there, buddy. Tell me what you meant by saving the planet.”

“I meant save it from Gershon. Who, I guess, was trying to seed it with Earth life. In his suit there would’ve been caches of blue-green algae. Closing the ecological loops, pumping out oxygen to balance the suit-wearer’s breathing out of carbon dioxide. Release that, I guess he figured, and even in this wan sunlight the algae could start busily photosynthesising, and pumping oxygen into Voga’s air. And Earth life gets a foothold. It might have worked.”

“Well, is that so bad?”

“Yes! Because Voga already has life! It must. The hydrogen envelope, remember? That keeps the surface warm, but must get regularly stripped away, as the planet approaches the Sun.”

“Ah. Right. So, you think, there must be some kind of—of hydrogen-excreting bug down there that replaces the hydrogen in the air.”

“The way photosynthetic bugs on Earth replenish the oxygen, yes. And the hydrogen layer keeps the whole world warm, including the bugs, until Voga returns to the sunlight once more.”

“It’s a deep space Gaia, then. Life and geology working together to sustain a living world.”

“I think so. I’m guessing. The point is, though, that if Earth life does get established here, it will start releasing oxygen, that’s going to react with the hydrogen, to make water—there will be a one-off rain—and the hydrogen greenhouse will shut down for good, and everything will freeze. The Earth bugs too.”

“Not good.”

“Indeed. Gershon should have figured it out himself... We’ll have to confirm all this when we go down to the surface. Ideally, by finding some hydrogen-excreting bugs.”

“Right. And we do have to go down to the surface, don’t we?”

“We do,” Salo said heavily. “Our primary mission was to get Gershon under control before he harmed the planet. Well, now he has smeared himself all over the place—”

“We’ll have to go down and clean it all up.”

“Every scrap,” he said gloomily. “And then we have to wait years until the retrieval crew gets out here, and slog our way home.”

That was my cue. “Maybe not,” I said.

He looked at me. “Hm?”

I nodded at the images of the planet in our screens. “We need hydrogen propellant, right? Well, there’s a big fat layer of it just waiting for us out there. If we could rig up some kind of scoop, I’m thinking, and have Malenfant dip into the outer layers of the atmosphere—”

His eyes widened.

“We could cannibalise One Small Step for tankage—”

“Winifred, you’re a genius.”

“Thanks.”

“But a criminal genius. They used to call that technique profac. Mining a world’s air for fuel. It’s illegal now. Because it’s an example of in situ resource utilisation: making your own fuel, and messing up the local environment in the process.”

“It’s not illegal if we are trying to save our lives.”

He frowned, evidently thinking hard. “True, but strictly speaking we’re just cutting short an unpleasantly long stay. On the other hand, we are reducing the risk of some malfunction killing us off in the years before the relief crew gets here, aren’t we? Maybe there’s a case... We need legal advice. Where’s the nearest Answerer?”

“Two hundred AU away.”

He grinned.

“We could always send a message—”

“Shut up.”

I thought it over. “I wonder if Armstrong used in situ resource utilisation to get back from the Moon.”

Salo shrugged. “Don’t know. Gulliver did, for sure. Built a canoe to get away from the land of the Houyhnhnms. Used the skin of yahoos to make a sail. But that’s another story. You finished your coffee? Let’s get to work.”

So we did.

You know, it’s a shame. If Gershon had stuck to the Last Small Step rules, at least we could have left the standard marker. As it was, Joe Salo scrubbed every square centimetre of rock clean of his footsteps.

And I took down his flag and brought it home.