The Next Continent (20 page)

They were in a huge clearing cut from a forest. Between the helipad and a group of prefab buildings stood a pair of single-story structures the size of gymnasiums. Alongside was a power distribution station, encircled by a high fence.

The core of the facility, however, was not the buildings. It was the huge area of sunken ground in the center of the site. The visitors had seen it from the air. The barren depression, hundreds of yards across, was dotted with mounds of earth several meters high and crisscrossed by trenches that looked like parched riverbeds. There was an area full of huge scattered boulders and many sheer escarpments.

These were not natural features. They had been created artificially to achieve some purpose. The proving ground was enormous, a rough square a thousand yards on a side. If the visitors did not know they were on Japan's main island of Honshu, they might have assumed they were in some remote foreign location. In the distance, rising above the trees surrounding the helipad, rose a titanic conical volcano: Mount Fuji. The proving ground had been carved from part of a training area for the Ground Self-Defense Force.

A Jeep met the visitors as they left the pad. They climbed aboard and headed toward the testing area. The road climbed a shallow rise. As the Jeep reached the top, the girl said to the driver, “Stop the car, please.”

“You can see everything from the control center,” said the driver. “The chief engineer is waiting.”

“It's all right. Stop here,” said the old man. The driver reluctantly stopped. The girl got out and the old man joined her. Seen from the top of the rise, the vast depression before them looked like an open-air habitat for wild animals.

Down in the basin were several small structures sunken halfway into the ground, constructed from concrete blocks and seemingly scattered at random. No two were alike. One appeared to be under construction; only a section of wall was complete.

A number of white vehicles resembling small bulldozers were moving busily among the buildings. Compared to normal bulldozers, they were broad and low-slung. The shank supporting the blade was slender; the treads were wide. There was no operator compartment. Sensor masts protruded from the spines of the vehicles like the necks of giraffes. At the end of the masts, multiple lenses of video cameras glinted in the sun. Slender cables, nearly invisible against the background, sprouted from the masts. One had to look closely to see that these cables led back to a thirtymeter tower at the edge of the depression. There were six robot bulldozers in the basin, all connected to the same tower. There must have been some tension on the cables, because instead of curving toward the ground, they extended to the tower in a straight line, making each robot look a bit like a dog on a leash.

There was little sound. Each bulldozer was about the size of a four-ton truck, but considering that six of them were moving about, it was eerily quiet. All that was audible was a low hum.

“Electric,” said the old man to himself.

The driver left the Jeep and joined them. “Yes. Seventy-five kilowatt motors. The cables are superconductive. Can't use diesel power plants where these things are going. Electric motors supply nearly all the motive power. There's a lot more to our multidozers than that though.”

“Is that what you call them?”

“Yes,” said the driver. “Multipurpose lunar surface engineering equipment. As the name indicates, they fulfill multiple roles: as bulldozers, forklifts, rippers, trucks, road rollers, and snowplows. Today is their final prelaunch shakedown.” The driver's chest swelled with pride. “Komatsu, Honda, and IHI developed them under our direction. It was a tremendous challenge, but we're very happy with the results.”

“What was difficult about it?” asked the old man. The driver kept glancing at the black-haired girl, who kept silent.

“First of all, configuring them for low-gravity operation. One-sixth G raises the units' center of gravity by a factor of six. Even small variations in the terrain could make them flip over during normal operations. So we've kept them wide and low to the ground. There's also the vacuum of space. Naturally, any sort of internal combustion device is out of the question, as are air-cooled radiators. Heat will build up inside the machines, so we distributed Freon heat sinks inside the bodies. The vacuum also makes lubrication difficult. Any volatiles will evaporate, so all moving parts and bearings are self-lubricating. We used molybdenum oxide alloy plating with a very low coefficient of friction.”

“And?” said the old man.

“Maintenance-free operation was another important consideration. We took great pains to design out structures that might fail. That's also why we avoided compressor-driven heat pumps or nitrogen-based lubricants. If we couldn't design out a failureprone component, we made it easy to swap in a replacement. Every component of the robots you see, including the treads, can be repaired or replaced without tools.”

“Very interesting.”

“The biggest challenge was limiting the total weight to under five tons. That was an absolute requirement to meet payload limits.”

“Is that why they look so flimsy?” The old man moved his hand back and forth at the wrist, like the neck of a snake. “Looks like those blades would snap with a bit of strain.”

“Well, it wouldn't do to cut the weight too much. If the unit is too light, it will be pushed back.”

“Pushed back? By what?”

“By the surface.” The driver grinned. “Terrestrial construction equipment is massively built because it will be pushing heavy mass around. If it were lighter, it would just end up applying force against itself. This effect is even more marked on the moon. When that blade cuts into the regolith, it could just lever the machine off the surface. So we'll be using regolith as ballast to increase the mass. The dozers need the structural strength to stand up to heavy loading and still be light enough to make the journey from Earth. This is one area where we really showed what we can do.”

“Interesting. Did you hear that, Tae?”

“Amazing.” She nodded briefly, not looking particularly impressed. The driver scratched his head. Maybe the technical details were boring her.

The driver's wearcom beeped. He spoke briefly and turned back to his two guests. “The test is starting. What would you like to do?”

“We'll watch it from here,” said Tae. She reclined on the hood of the Jeep. The old man stood next to her. The driver gave up trying to coax them to the control center and stood silently watching.

The multidozers had been moving independently but suddenly began moving in unison. Their destination was a pile of refrigerator-size concrete blocks at the edge of the basin. Forks emerged from the front of the machines, each one lifting a block. Then they formed up and began slowly moving forward in a column. But instead of using the blocks for construction, the robot vehicles headed toward the area of scattered boulders, which were around half their size.

Even in the area of boulders, the machines hardly slowed. Some of the boulders were too large to crawl over, but each time a dozer encountered one that was too large, it skillfully moved its treads alternately back and forth to maneuver through the gaps between rocks.

Then the lead dozer reached a boulder that was noticeably larger than the others. It was flanked by other boulders and there appeared to be no way around it. A dead end. The line paused for a few moments. Dozers 1 and 2 moved aside and placed their blocks on the ground. The two machines maneuvered back and forth repeatedly in the narrow cul-de-sac until they were side by side in front of the boulder. Once aligned perfectly, they extended their forks under the rock in perfect synchronization and gradually levered it off the ground. One dozer would not have been able to lift it. With two it was a different story. Their combined power tipped the boulder, and it rolled out of the way, opening a path.

The cameras on the sensor masts of the lead machines busily swept from side to side. Once they were certain they could move forward, the two robots retrieved their blocks, formed a line again, and moved through the gap as if nothing had happened.

The old man clapped briefly. “Very good, for remote control. It's not easy, is it?”

The driver chuckled. “That wasn't remote control. No human intervention. The multidozers are capable of self-directed action. The cables supply power only.”

“So those are robots?”

“Initial construction will be carried out without a human presence. Even if we tried to control everything from Earth, it takes close to three seconds for signals to reach the moon and return. If there's an emergency—say, a landslide—we might not be able to respond fast enough. So everything is AI controlled. Developing the software was harder than designing the hardware.” The driver watched the machines affectionately. Evidently he had been personally involved in their development.

“Our multidozers can work in perfect synchronization and respond independently to emergencies. That's a critical requirement for construction on the lunar surface, and it's the focus of this test. But we're not finished yet. The next hurdle is operation on sloping terrain. It's very easy to flip over on the moon.”

The driver pointed to an embankment. Dozer 1 was already climbing it. The embankment was extremely steep, perhaps thirty degrees. The machines began moving horizontally across it, all at the same elevation, forks held level to avoid dropping the concrete blocks. Their agility was impressive. But after a few minutes, the line stopped again. A two-meter trench had been cut into the face of the slope.

“That gouge in the slope is wide enough for the multidozer to lose traction and slide down if it tries to cross using its treads. What are they going to do?”

Dozer 1's cameras scanned back and forth. At first it seemed to be at a loss for a solution. But once again the machines found a way.

Each dozer was equipped with a load bed. Dozer 2 raised its forks and moved forward, as if to place its block on the back of the lead machine. However, instead of depositing it there, it simply rested its forks on Dozer 1's back. It seemed to be calculating how much downward force to apply.

The two machines now started forward, maintaining the same attitude. Dozer 1's treads projected out over the trench and gained a purchase on the opposite side. It crossed over. Then, as the second machine's treads projected over the trench, Dozer 3 placed its forks on its back in the same way, adding the weight of its block. In this fashion the dozer line crossed over one by one.

The driver whooped with excitement. “Pressure from behind to generate more traction! Too much pressure and they'd fall, so they had to calibrate it. These multidozers are way more advanced than the previous generation.”

“But what if they can't figure it out?” said the old man.

“Unless it's an emergency, they're programmed to stop and wait for instructions. That's what the old model had to do when it reached this point. They've really come a long way.”

The machines continued across the trench. The last dozer extended its treads over the gap. This was going to be a bit tricky. There was no machine behind it to hold it against the ground.

Dozer 6 lowered its forks until they were level with the ground. Its forks projected beyond the block it was carrying, and it slipped them under the chassis of Dozer 5. Dozer 6 then lifted Dozer 5 slightly, increasing its own load. To compensate for its loss of traction, Dozer 5 carried out the same maneuver with Dozer 4, which was completely across the trench and had full contact with the ground. With the three machines moving as one, Dozer 6 was able to cross.

The old man murmured, “I bet they're smarter than people.”

“We'll see,” said the driver. “The last test is coming up.”

The line had reached the end of the embankment and was back on level ground. There seemed to be no further obstacles. Instead there were several steel panels scattered across the ground, about four meters square.

The line reached one of the panels. The first and second dozers crossed over. When Dozer 3 was on the panel, the trap was sprung.

The panel split down the middle and opened downward. The rear three-quarters of Dozer 3 was directly over the opening. The machine tipped backward and began to teeter over the hole.

The other dozers, which had been lumbering steadily forward, moved with startling agility. Dozers 1 and 2 backed up rapidly, while the three trailing units sped forward, wedging Dozer 3 front and rear. The line froze, with Dozer 3 nearly suspended in space.

“This is the cave-in response test. Lunar regolith is a lot like dry desert sand. With vibration it can collapse, even where it's packed down. What will they do now?”

The situation resembled the trench-crossing test, but this new gap was too wide for the dozers to cross. Dozer 3 clearly could not get out of this one on its own. Somehow it would have to be raised. The multidozers began solving the problem in a straightforward fashion.

First, Dozers 2 and 4 used their clawlike rippers to grip the ground, locking Dozer 3 in position. Next, the lead and tail dozers dropped their blocks, circled to opposite sides of the line, and approached Dozer 3 at an angle, forks extended. They moved very slowly, seemingly wary of the possibility of a secondary collapse.

When they reached the edge of the gap, they extended their forks under Dozer 3. Dozers 2 and 4 then retracted their rippers and moved away, transferring Dozer 3's weight to Dozers 1 and 6. Then 3 was raised in a controlled manner.

The old man murmured as he watched the robots' complicated movements. “Aren't you worried about getting those cables tangled with all that maneuvering?”

“It's not a problem. The power supply tower can automatically reposition the cable linkage points.”

“But what if one of the cables is cut?”

“The dozers have onboard fuel cells. They can move independently for short periods of time, enough to make their way back to the power pole to hook up with a new cable.”