The Silent War

ASTEROID VESTA

An individual nanomachine is like an individual ant: mindless but unceasingly active. Its blindly endless activity is of little consequence by itself; even the most tireless exertions of a device no bigger than a virus can be nothing but invisibly minuscule in the human scale of things.

But while an individual ant can achieve little and has not enough brain to accomplish more than instinctual actions, an ant colony of many millions of blindly scurrying units can strip a forest, build a city, act with a purposefulness that seems little short of human intelligence.

So it is with nanomachines. An individual unit can accomplish little. But strew millions of those virus-sized units over a restricted area and they can build or destroy on a scale that rivals human capacities.

The asteroid Vesta is a spheroid rich in nickel-iron, some 500 kilometers in diameter. The Humphries Space Systems base on Vesta was burrowed, for the most part, more than twenty meters below the asteroid’s pitted, airless, bare surface. The nanomachines that were strewn across a small area of the asteroid’s surface operated in a far different regime of scale and environment. Their world was a universe of endlessly vibrating, quivering molecules where electromagnetic forces held atoms in tight clusters, and Brownian motion buffeted atoms, molecules and nanomachines alike. On that scale of size, the nanomachines were giant mechanical devices, like huge bulldozers or derricks, bulling their way through the constantly jostling, jiggling molecules.

Each nanomachine was built with a set of grippers that fit the shape of the molecule that made up high-grade steel. Each nanomachine had the strength to seize such molecules and pull them apart into their constituent atoms of iron, carbon, chromium, and nickel.

Drawing their energy from the unceasing Brownian vibrations of the molecules themselves, the nanomachines patiently, mindlessly, tirelessly chewed through every molecule of steel they could find, tearing them apart. On the molecular scale of the nanomachines this was a simple operation. It would end only when the quantum-dot timing devices built into each individual nanomachine told it to stop and disassemble itself.

Or when the nanos ran out of steel to chew on. Whichever came first.

Leeza Chaptal was the first to understand what was happening. As she stood in the control center deep underground and watched the monitor screens go blank, one by one, she realized that only the sensors and other equipment up on the surface were failing.

The technicians seated at their consoles around her had gone from surprise to irritation to outright fear.

“Something’s wiping out everything up on the surface,” one of them said, needlessly. They could all see that.

“Those missiles,” said Leeza. “They must be responsible for this.”

“But what… how?”

“There wasn’t any explosion,” said one of the puzzled technicians. “Nothing seismic registered except their crashing on the surface.”

“And then everything started blanking out.” “Nanomachines,” Leeza guessed. “They must have brought in nanomachines that are eating up our surface installations.”

All the techs turned to her in wide-eyed fear. Nanomachines. They had all heard stories about how they could chew up everything, including people, and turn everything in their path into a dead, formless gray goo.

“Somebody’s got to go up the surface and see what’s going on up there.”

Nobody budged.

Leeza hadn’t expected volunteers. “I’ll go myself,” she said.

Leeza’s heart was already thumping loudly as she clumped to the hatch in the awkward, bulbous hard-shell space suit. Then she saw that the display on the hatch opening onto the vertical shaft that led up to the surface showed that there was nothing but vacuum on its other side.

Omygod, she gasped silently. They’ve eaten through the hatch at the top of the shaft.

Should I go through? What if they infect my suit? What if they start chewing on me?

Yet she had to know what was going on, had to learn the nature and depth of the attack they were undergoing.

Turning to the two maintenance engineers who had helped her into the suit, she said through its fishbowl helmet, “Get back on the other side of the hatch down the corridor.”

They didn’t need to be told twice. Both of them scampered down the corridor and squeezed through the hatch together, neither one of them willing to wait for the other. Leeza heard the metallic thud when they slammed the hatch and sealed it.

Okay, she told herself. Just a quick peek. A fast reconnaissance. Nothing heroic.

With gloved fingers she tapped the code on the hatch’s control panel. It popped open slightly, and she noticed a puff of gritty dust from the floor swirl through the crack.

Breathing heavily inside her helmet, she pushed the hatch all the way open and stepped tentatively through. The lamps fixed to the shoulders of her space suit reflected light off the steel wall of the shaft.

“Looks all right so far,” she said into her helmet microphone to the techs in the control center watching her progress in the corridor’s surveillance camera.

“Some dust or dirt accumulated on the floor of the shaft,” she reported, kicking up little lingering clouds of dust as she turned a full circle.

She had to crane her neck painfully to look up the length of the shaft. Sure enough, the hatch up at the top was gone. She could see a swatch of stars in the circular opening up there. Feeling jumpier with every heartbeat, Leeza unclipped the hand torch from her waist and shone it up the shaft. The gleaming reflection from the smooth steel lining ended about halfway up.

“The metal lining of the shaft seems to have been eroded or something,” she said. A pebble pinged on her helmet. She would have jumped halfway out of her skin if she hadn’t been inside the cumbersome suit.

“It’s eating the metal!” she yelped.

“Get back inside,” said one of the techs from the control center. “Get back before they start chewing on you!”

Leeza didn’t wait to be told twice.

There was no nanotech expert among the HSS crew at the Vesta base. And no way to call for advice or information, with all the surface antennas gone. Leeza ordered the entire team into the galley, the only room large enough to hold the nearly two hundred men and women in the base at the same time.

“It’s nanomachines,” she concluded, after reporting to them what was happening. “They seem to be attacking metal. Maybe they’re specifically programmed to destroy steel, maybe it’s any metal at all. We don’t know. But either way, we’re in deep trouble.”

“They could eat out all the hatches and open the whole complex to vacuum!” said one of the mercenary soldiers.

“That’s what they’re in the process of doing,” Leeza admitted.

The head of the logistics storeroom, a soft-looking sandy-haired man with a bold blue stylized wolf tattooed across his forehead, spoke up:

“They’re coming down the shaft and eating at the airtight hatch, right?”

“Right,” said Leeza.

“And when they’ve gone through that first hatch they’ll come along the corridor toward the next hatch, right?”

“We all know that!” snapped a dark-haired woman in pale green coveralls. “They’ll eat up anything metal.”

“Well,” said the logistics man, “why don’t we spray the corridors and hatches with something nonmetallic?”

“Spray?”

“We’ve got sprayguns, ceramics torches, butterknives, for chrissakes. Cover every square millimeter of exposed metal with something nonmetallic. Slather it on good and thick. Maybe that’ll stop the nanos.”

“That’s ridiculous!”

“Maybe not.”

“It’s worth a try.”

Leeza agreed that it was worth a try. If nothing else, it would keep everybody busy, instead of waiting in dread for the nanomachines to kill them.