But it is not zero. By chance, the trajectories of this nameless stone and a spacecraft launched by humans would intersect somewhere between Earth and Mars. It was an almost incredible coincidence, something that had rarely happened in the short history of human spaceflight. It was a chance occurrence that belonged to two categories at once—probably won’t happen and must not happen. The spacecraft that the stone approached at a speed of over 130 kilometers per second—seen from the perspective of the stone—was not prepared for this. Nothing could prepare a spacecraft for such a collision. The impact would release the energy of a nuclear explosion, even though the stone’s diameter was less than a man’s wrist-to-elbow length.
The spaceship ILSE 2 was asleep to conserve energy. It was en route to the moon of a distant planet that had been closely studied by humans only twice, where it was supposed to meet its sister ship, ILSE 1. But the artificial intelligence on board already knew this encounter would never happen. It had noticed the stone two seconds ago and had used trillions of computing cycles and thousands of simulations to calculate its path. It compared this with the abilities of the ship’s drives and realized that no course correction could prevent the collision. The AI had known about this blind spot since before the launch of the spacecraft, as soon as it had been fed the data. It knew the available technology would discover obstacles of a certain size too late to change the course of the ship in time. It was not scared by this, as it knew it would survive a collision. A meteorite of that size could destroy one of the modules, but not the entire ship. The AI would then quickly retreat to a computer located in a different module.
Therefore, it was not upset when the stone came closer. The AI left the ship in standby mode. At this point, it certainly would be too late to hand the ship over to human control. Three seconds before impact, it started a starboard engine. Not much seemed to happen, but by this small change in position, the AI caused the stone to impact at the spot where it would do the least damage—right before the engines, where titanium alloy girders separated them from the habitable modules.
There were two seconds left. The AI used this long interval to train the pattern recognition of its neural network. Then it registered that the strong arms connecting the ship to its engines were torn off. A loud blow lasting only a few milliseconds was transmitted through the body of the spaceship. Otherwise, all was silent. The frame absorbed the kinetic energy of the stone, comparable to a small atomic bomb, but without the shockwave, because even destruction worked soundlessly in the vacuum of space. The engines, no longer connected to the spaceship, shut off automatically. The life support systems could work only a few hours on battery power. The AI deactivated them permanently.
It also went to sleep itself, in order not to waste the batteries. It did not regret this action. The connection to Earth had been severed, but its sensors were all online. It could now observe the wonders of space for several millennia, while the spacecraft shot past Saturn with undiminished speed and eventually left the solar system. If the programmers had given the AI a sense of irony, it might have been amused by what it saw of the ship—the engines, now turned off, were unflinchingly following the command module, like a dog following its master even without a leash.
However, the programmers had decided the AI did not need the tool of irony to fulfill its tasks. That would have been a waste of capacity. The AI was curious, though, and this curiosity would save it from going insane in the millennia to come.
Programmers are pragmatic people. That was the reason they had not given the AI a sense of responsibility for its human creators, as ILSE 2 was an unmanned ship. Therefore, after the collision the AI did not regret that the spacecraft could no longer fulfill its task of bringing supplies to the humans aboard ILSE 1 when they reached their goal. Humans would discover this glitch a week later, when Mission Control would try to wake ILSE 2 from standby mode and would receive no response.
July 4, 2046, ILSE
Martin assumed his very own death might be waiting for him. It could be over, between one second and the next—I know this. He already had been conscious of this on Earth. In his everyday life, moving between the apartment, the office, and the supermarket, he had wasted no thought on the idea. Out here, on the other hand, he could not get used to the idea of always being threatened by death without seeing it coming. Perhaps there had been a minor collision in the asteroid belt several thousand years ago. Maybe a comet, on its path for millions of years, had lost some of its material around here. Death did not have to be fast to hit him. It could simply be waiting for ILSE, the spaceship that hurled him toward Saturn at 50 kilometers per second. To be more precise, the spacecraft that was moving him toward the point where the planet Saturn, which now had just emerged from behind the sun, would be located several months from now.
ILSE, the International Life Search Expedition. The name is too pretentious, he felt. When he pronounced the acronym I.L.S.E—as a word in his mother’s language —the others gave him funny looks. Jiaying, the Chinese woman, then tried to repeat the word with a German accent. She was linguistically talented, but it still sounded like ‘Ull-see’ rather than ‘Ill-see.’
Martin looked at the ceiling, which was gradually getting brighter. A meteorite could hit here at any moment, he imagined. There was only a third of a meter of fabric between his cabin and space. This was not just any fabric, though, but a ceramic textile folded into about a dozen layers—a ‘stuffed Whipple shield.’ The shield material consisted of special foam sprayed between the textile layers. As the foam dispersed, it formed numerous small, airtight chambers. Whatever hit the exterior wall was supposed to splinter into numerous pieces that would further fragment in the next layer and finally get stuck in the foam, which closed up again after it cooled off. It even worked. He had seen the small holes on the outside of the hull in the images taken by the spider robots.
Of course, this only worked if the meteorite was small enough. Up to five centimeters the system would be fine, the experts on Earth had said. The probability of encountering a bigger rock on the way to Saturn was quite low. In addition, the wall of his cabin did not point in the direction of their travel. When Martin realized this, he breathed a sigh of relief. If ILSE sprung a leak somewhere, the artificial intelligence would immediately close all bulkhead doors and isolate the affected module.