Death's End

Looking back, the Staircase Program implemented at the beginning of the Crisis Era was a similar advance. Using only the primitive technology available at the time, it managed to boost a small probe to 1 percent of lightspeed. This achievement should have been impossible without technology that would not appear for another one and a half centuries.

At the time of the Staircase Program, humans had already successfully launched a few spacecraft outside the Solar System and had managed to land probes on Neptunian satellites. Thus, the requisite technology to distribute nuclear bombs along the acceleration leg of the probe’s course was relatively mature. But controlling the flight path of the probe to pass by each bomb, and detonating each at the precise moment, posed great technical challenges.

Every bomb had to detonate just as the radiation sail passed it. The distance from each bomb to the sail at the moment of the explosion ranged from three thousand to ten thousand meters, depending on the bomb’s yield. As the probe’s velocity increased, the timing needed to be more precise. However, even as the sail’s speed reached 1 percent of lightspeed, the margin for error remained above the nanosecond range, well achievable by the technology of the time.

The probe itself contained no engine. Its direction was entirely determined by the relative positions of the detonating bombs. Each bomb along the route was equipped with small positional thrusters. As the sail passed each bomb, the distance between them was only a few hundred meters. By adjusting this distance, it was possible to alter the angle between the sail and the propulsive force generated by the nuclear explosion, and thus control the direction of flight.

The radiation sail was a thin film, and the only way to carry the payload was to drag it behind in a capsule. The entire probe thus resembled a giant parachute—except that the parachute flew “upwards.” To avoid damage to the payload from the nuclear explosions occurring three to ten kilometers behind the sail, the cables connecting the sail to the payload had to be very long: about five hundred kilometers. An ablative layer protected the payload capsule itself. As the nuclear bombs exploded, the ablative material gradually vaporized, cooling the capsule as well as lowering the total mass.

The cables were made from a nanomaterial called “Flying Blade.” Only about a tenth of the thickness of a strand of spider silk, the cables were invisible to the naked eye. Eight grams of the material could be stretched into a cable one hundred kilometers long, yet it was strong enough to securely pull the payload capsule during acceleration, and would not break from the massive radiation generated by the nuclear explosions.

Of course, Huolong Chu Shui was not, in fact, equivalent to a two-stage rocket, and the repeating crossbow was not the same as a machine gun. Similarly, the Staircase Program could not bring about a new Space Age. It was only a desperate attempt that drew upon everything humanity’s primitive level of technology could offer.

Crisis Era, Years 1–4 Cheng Xin

The mass launch of Peacekeeper missiles had been in process for over half an hour. Trails from six missiles merged together, and, lit up by the moon, resembled a silvery road that reached into heaven.

Every five minutes, another fiery ball ascended this silvery road into the sky. Shadows cast by trees and people swept along the ground like the second hands of clocks. This first launch would involve thirty missiles, sending three hundred nuclear warheads with yields ranging from five hundred kilotons to 2.5 megatons into orbit.

At the same time, in Russia and China, Topol and Dongfeng missiles were also rising into the sky. The scene resembled a doomsday scenario, but Cheng Xin could tell by the curvature of the rocket trails that these were orbital launches instead of intercontinental strikes. These devices, which could have killed billions, would never return to the surface of the Earth. They would pool their enormous power to accelerate a feather to 1 percent of the speed of light.

Cheng Xin’s eyes filled with hot tears. Each ascending rocket lit them up like bright, glistening pools. She told herself again and again that no matter what happened next, it was worth it to have pushed the Staircase Program this far.

But the two men beside her, Vadimov and Wade, seemed unmoved by the spectacular scene playing out before them. They didn’t even bother looking up; instead, they smoked and conversed in low voices. Cheng Xin knew very well what they were discussing: who would be chosen for the Staircase Program.