Of course, this was the ultimate goal. Getting there was going to take some time. Kali was still moving into position around Uranus and the accretion disk was still being tweaked. In the meantime we’d been working on getting the kinks out of the energy transmission system.
Things had gone pretty smoothly at first. The robot had successfully completed the antenna array, and microwave power generation with the accretion disk was achieved for the first time. But then the array had started sending some strange telemetry, indicating that Rapushinupurukuru was beginning to rotate, at first very slowly. The signal began dropping and recovering intermittently, with indications that the rotational speed was picking up. Then we lost the signal completely.
Telemetry analysis didn’t tell us much, but it did point to a mystery beyond that of the asteroid’s anomalous rotation. The array had been receiving faint signals unrelated to the control signals for the construction bot. All we knew was that the signals were not some natural phenomenon. And their connection with Rapushinupurukuru’s anomalous rotation? Equally unknown.
There was just too much going on here, and you never know until you go. The Guardians—that’s what we are—were set up for just this kind of problem.
The Guardians were AADD’s security enforcement arm. We dealt with just about everything connected with security. We helped keep the peace. But mostly what we did was get people out of trouble. And sometimes, if AADD’s progress was at stake, we carried out investigations.
The origin of the Guardians went back to the early days of space colonists forming their own security organizations. As the space cities grew, these police forces became more specialized and professional. After AADD was formed, it took all these scattered groups and unified them into the Guardians.
We were the closest team to Rapushinupurukuru when the problem was detected. Dragonslayer was our ride.
ABOVE OUR HEADS the ship seemed to be moving slowly, but of course it was Barbara and I who were actually moving. Although the asteroid’s rotation made it useless as a microwave relay node, on the surface the motion didn’t seem so noticeable. Farthest away from the axis of rotation the centrifugal force was a mere 0.03 G. Close to the axis it was barely perceptible, though a misstep could send you off on a short trajectory.
“Hey, Seiya, what’s the deal with these supports? Were they designed to be this short?”
“Not likely,” I answered. I looked at the surface. Some of the little craters must have formed before life even began on Earth. Most asteroids, except for the densest, were covered in regolith—especially the big ones where distances were measured in kilometers. They usually had enough gravity to hold on to a blanket of fine material.
Asteroids like Rapu had so little gravity that the finer particles created in collisions usually traveled fast enough to escape into space. This left a regolith blanket of coarser rock. I could tell just by looking that the layer under my boots wasn’t very thick. I felt its granules crunch under my feet like gravel. If there’d been an atmosphere, I would have heard it too.
Rapushinupurukuru was at most only twelve hundred meters long, so the horizon was extremely close. On the surface, it felt like you were standing atop a tall building—a building with a penthouse rock garden. The horizon seemed to drop off into an abyss, but if you kept walking, more gray rock just kept coming up.
Before we started any further analysis we had to take a look at the microwave antenna array the robot had built. The surface in the shadow of the mesh antenna was redder than on the far side, testimony to the fact that until recently Rapushinupurukuru hadn’t rotated. Rock weathered even in the vacuum of space. There were microimpacts, charged particles from the Sun—you name it. Under the influence of weathering processes, nanometer-sized iron particles were knocked out of the silicate matrix and came to cover the rock’s surface, giving it a slightly reddish cast.
From the ship, the reddening of the near side seemed pretty uniform. But down on the surface the weathering patterns looked very complex. They reminded me of Mars after a dust storm, the density of the iron particles varying with the terrain. All these delicate textures and hues testified to the passage of hundreds of millions of years. It was incredible to think that even in this terrible isolation, natural processes continued to operate, leaving their fingerprints behind.
In the center of the near side was a forest of aluminum columns. The white shapes seemed to have grown out of the surface. These pale alloy columns were just as inorganic as the iron desert from which they appeared to spring, and yet somehow they seemed mysteriously at home here. We humans were the ones out of place.
We hadn’t taken much notice of it from the ship, but once we were on the surface it was clear that the columns weren’t nearly as tall as the design called for. On the other hand, the spacing and number of columns matched the plans exactly.
According to the blueprints for the array the columns were supposed to extend as much as ten meters from the surface to allow for local variation in the terrain. This was pretty standard and was intended to deal with just about any terrain variation that might be encountered on an asteroid. The columns themselves were just L-shaped stock bonded at the edges to form square supports for the array. They were light enough that robots could build very large structures with relative ease.
So why was the antenna no more than two meters off the surface? In some spots there was only half a meter or so of clearance. The underside of the array was supposed to look something like a huge gymnasium, with a ceiling of up to ten meters. This was something else entirely. It reminded me of a hydroponic tomato farm I once saw. It wasn’t just that the mesh antenna was close enough to reach up and touch; in some spots you’d actually have to crawl to get under it. The columns were fairly flimsy, just strong enough to support the huge array in microgravity. Bumping up against one of them by accident could bend it out of shape.
“We’re gonna have to crawl if we want to get under this thing,” said Barbara.
“I’d rather not try it.” Our hard-shell suits were pressurized at one atmosphere. This made them quick to get in and out of—no more hours spent prebreathing pressurized pure oxygen like the old-time astronauts. But the suit had to be very stiff to stand up to one atmosphere of internal pressure with a surrounding vacuum. It wasn’t the kind of thing you could go shimmying around in. We weren’t prepared for that.
“Maybe we’d better let the eyeball handle this. Let’s take a walk around the perimeter in the meantime.”
Barbara signaled agreement by extracting a red sphere about the size of a tennis ball from her utility pack. The eyeball had twenty-four pinhole thrusters distributed over its surface. Tiny streams of combustion gases allowed it to maneuver freely in low-G environments. It could be guided into inaccessible or dangerous spaces to send back visual and other data.
Getting a signal out from under the antenna was going to be difficult; our suits would serve as transmission relays for Dragonslayer. The eyeball was red, as was the surface, although not the same hue. Still, as the little sphere floated under the array it looked almost like some natural inhabitant of this rock, released into its native environment. The way it rose up from the palm of Barbara’s hand indicated that it was already being guided from the ship.
“So what do you think, Seiya? Are these off-nominal or what? Has this got something to do with our rotation riddle?”
“The rotation and the length of these columns? Neither is natural, but that’s all they have in common. The robot’s AI was sophisticated enough to allow it to deal with most problems it might run into during construction, but I can’t see why it would build these this way.”
“This isn’t to spec, right?”
“Nowhere near. The question is whether there’s a causal link.”
“How about timing? The columns get shorter, then the rotation starts.”
“What’s the mechanism?”
“How should I know?”
“Look, Barbara. You’re right. Maybe th
e rotation is happening because something made the columns shorter. But you could also posit some extrinsic factor that shortened the columns and started Rapu spinning. In that case there’s no causal relationship between the height of the columns and the rotation.”
“Why assume an extrinsic factor?”
“How else do you explain the signal picked up by the array? It’s too regular to be natural.”
“Okay, so it’s too early to judge.”
“That’s what I’m getting at. This could be anything from a natural event to aliens messing with our stuff.”
The answer to the riddle of the columns came while we were still talking. Rebecca had been reviewing the ops logs for the construction bot. At least as far as the columns were concerned, the answer had nothing to do with little green men. One of the robot’s sensors had malfunctioned, causing it to calculate that it would run out of aluminum alloy stock ahead of schedule. The AI took that information and reconfigured the design with shorter columns. Fortunately the near side of the asteroid was fairly flat.
Space is a rough environment for any kind of mechanical device, so for the robot to experience a component failure was not surprising given the robot’s size and complexity. The AI had to be up to improvising in response to the unexpected. It wasn’t a genius, but within certain fixed parameters it was pretty sophisticated. It was designed to be a tool for humans; that didn’t include being curious about too many things.
So that explained the height of the columns. Images from the eyeball of the underside of the array showed that the robot had carefully deployed the power distribution cables to allow for the shorter column height.
“So everything is nominal, except that the bot screwed up the inventory calculation.” Something in Barbara’s voice suggested that she wasn’t totally convinced. “I guess this leaves us in the dark about the rotation.”
“No clear link to our mystery signal either,” I added. “I’m starting to wonder if it was a real signal.”
WE DECIDED to head back for a rest. When we got to the core block there was news.
“Look at this,” said Rebecca, holding out her web.
“They could’ve given it to us a little sooner,” I griped.
“Now, now, Seiya. We’re pretty far from Uranus. It took a while to import the whole database.”
I scanned the results of the query Rebecca had run. Neither of us was sure what to make of it.
“Rapushinupurukuru—formerly known as 2143SF—isn’t such a new object after all,” said Rebecca. “Apparently it was discovered once already, about a century ago. Back then it was called 2053CJ, but the orbital elements look pretty similar. Rapu’s outbound from Sol now, but the first time it was discovered it was almost at perihelion, and its track relative to Earth made it hard to calculate an orbit with much precision. It clearly wasn’t a collision threat, so they more or less ignored it.”
“It was discovered from Earth?”
“No. An astronomer on Callisto saw it first. A hundred years ago Callisto was crawling with them.”
There was a time early in the history of space colonization when everybody assumed that the outer planets, beginning with Jupiter, were the future of the solar system—mainly as sources of fuel for nuclear fusion. Work to develop that potential started very soon after humanity returned to space. For a while, a lot more capital was directed toward the gas giants than toward settlement on Mars. Investments on the red planet looked to have payback times measured in centuries, while Jovian fusion fuel seemed to guarantee quick, fat returns. Everybody on Earth threw money at it. In pretty short order Jupiter Fever created a bubble that would have made seventeenth-century Dutch tulip traders proud.
Recovering the precious fuel was one thing, getting it back to Earth was something else again. This was in the days before reliable spacecraft and basic space infrastructure, and the first settlers on Jupiter’s outer moons had to use the ships they rode in on as habitats, connecting them to create space towns.
The settlement on Callisto was self-sufficient from the beginning, at least at the level of basic survival. Supplying the colony from Earth was far too expensive. The colony was awash in hydrocarbons, so generating oxygen and growing or synthesizing food was straightforward, but useful goods and equipment were chronically in short supply. Callisto had the most advanced technology humanity had ever developed, but daily life was based on barter exchange.
The economy of Jupiter’s moons was directly affected by conditions on Earth. When the bubble was inflating, funding and resources were plentiful. When the bubble popped, Earth’s economy cratered, funding was frozen, and even the flow of vital supplies dried up. The colonists’ destinies were controlled by events taking place hundreds of millions of miles away.
Yet it was these colonists who, short of almost everything, assembled the data that was the basis for later exploitation of the Jovian system. They overhauled and refueled used boosters and cobbled together recycled components, sending one probe after another to the Galilean moons, even to Jupiter itself. The later full-scale missions to the outer planets could not have succeeded without the dedicated research of these early pioneers. The Callistans didn’t hesitate to press their habitats into service as makeshift probes. More than riches or cargo from Earth, these colonists craved knowledge, and the strange new world before them constantly stimulated this hunger.
Given their history, I could easily believe the Jovians had spotted 2053CJ. “Are you sure they didn’t send a probe? Unmanned at least? An S-type asteroid at such a steep angle to the ecliptic has got to be pretty interesting to any planetary scientist worth his salt. Think of the data they could’ve collected on how Jupiter’s gravity interacts with the orbits of these little rocks.”
“That’s what I thought,” said Rebecca. “But querying the database for 2053CJ returned zip in terms of unmanned probe data.” Rebecca sent a graphic of the orbits for Jupiter and Rapushinupurukuru to the main monitor. At aphelion the asteroid was three astronomical units from the Sun. Its orbit was nearly vertical to the plane of the ecliptic. At its ascending node across the ecliptic plane, it was around 5.4 AU from the Sun. The average radius of Jupiter’s orbit was 5.2 AU. Sooner or later significant gravitational interaction between the two bodies was inevitable. It seemed likely that the disappearance of 2053CJ and its later rediscovery as 2143SF should be chalked up to Jovian gravitational influence.
“2053CJ was a very interesting object from a planetary science perspective. Its discoverers knew that it reached its ascending node 540 days after perihelion. But its angle to the ecliptic was just too large for a probe from Callisto to reach. In addition to reducing relative velocity to zero, a probe would’ve had to adopt the same steep angle to the ecliptic. At the very least, it would have had to accelerate to twenty kilometers per second to get there. I’m sure the settlers on Callisto wanted to send a probe to investigate further, but it just wasn’t going to work. That’s why there’s nothing in the database.”
2053CJ reappearing a century later as 2143SF was definitely interesting, but it wasn’t the key to our problem. Once again we’d come up empty-handed. This was turning out to be harder than we’d expected. For a while we just sat staring at each other.
“Aren’t we forgetting something in this analysis?” I said.
“We’ve looked at everything. The robot, the microwave relay array…” said Barbara.
“It just hit me—we’ve been ignoring the biggest factor of them all.”
“What, Seiya?”
“Rapushinupurukuru itself.”
“READY TO DISPLAY results of analysis,” said the synthesized voice.
Barbara and I were still in the core block. I’d ordered a full workup on the asteroid, and Dragonslayer’s AI had just obliged.
“How’re we looking?”
“Nothing unexpected,” said Rebecca. “Except for one thing I’m surprised we didn’t notice. It looks like Rapu is a CAT.”
As their name implied, Comet-Ast
eroid Transition objects were comets that had exhausted most of their volatiles and were on the way to becoming plain old hunks of rock. Given Rapushinupurukuru’s highly inclined orbit, the possibility of it being a blown-out comet seemed at least plausible.
“The data suggest that Rapu carried a pretty light load of volatiles. Judging from the weathering profile, I’d guess the outer layer of volatiles boiled off quite a long time ago.” We were looking at a 3-D image of Rapushinupurukuru without its array, its reddish surface rotating slowly against a gray-white background. Regolith and weathered red rock. Even on the restricted scale of the solar system it was an insignificant heap of minerals, but I never got tired of staring at its surface.
After watching the image revolve ten times or so, it suddenly hit me. The asteroid was sheathed in its blanket of rock fragments. The mesh antenna had been covered with a fine dusting of regolith. Depending on mass and velocity, fragments kicked up through collisions either escaped and went into space or traced parabolic paths back to the surface. But there was no crater to explain the regolith on the array.
The Ouroboros Wave Page 8
