Excerpt from A Past Outside of Time The Staircase Program

In fourteenth-century China, during the Ming Dynasty, the Chinese navy invented a weapon called Huolong Chu Shui, literally meaning “fiery dragon issuing from water.” This was a multistage gunpowder rocket similar in principle to antiship missiles of the Common Era. The missile itself (Huolong) was augmented with booster rockets. When launched, the booster rockets propelled the missile toward the enemy ship by flying just above the surface of the water. As the booster rockets burnt out, they ignited a cluster of smaller rocket arrows stored inside the missile, and these would shoot out the front, causing massive damage to enemy ships.
Ancient warfare also saw the use of repeating crossbows, which prefigured Common Era machine guns. These appeared in both the West and the East, and Chinese versions have been discovered in tombs dating from the fourth century B.C.
Both of these weapon systems were attempts to utilize primitive technology in novel ways that demonstrated a power incongruous for their time period.
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.

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