Scattered Defenses

“Water you doing?”

After the first barrage, I saw the turrets swivel under newly activated AI control, and a torrent of violet plasma flow over the hull and harden against the crushing force of two opposing magnetic fields into a seething conflagration that crackled and sputtered pink fire.

Of the latter, the so-called “plasma window” had previously found use in electron-beam welding applications. Alone, it would stop nothing. But it would (mostly) hold an atmosphere. Great canisters along the ship’s broadside had slid open, exposing their contents to hard vacuum. The precious water within, ordinarily used for remass, was furiously boiling.

The next volley struck then, and even from the emergency redoubt, nestled deep within the ship’s interior, I felt the lurch as the cargo bay was gutted by a spinal-mount ray, even as I saw it burn cruelly in a visiplate.

But the steam and ice had by now fully formed, resublimating and desublimating into each other as crystals danced in the flames, and upon the third volley, their pencil-thin near-IR laser chewed into the mixture, and was absorbed and scattered by it. The hull amidships smoldered worrisomely in a wide circle, but it held.

To sustain one atmosphere in a plasma window requires a bit shy of 20 megawatts per square meter. But you can get away with a thousandth that if you settle for holding less pressure. Even so, banks of hydrogen batteries were rapidly discharging in an internal struggle the ship’s twin reactors would quickly lose. The ad-hoc shields could stay up for less than a minute, perhaps, before waste heat and power requirements forced them to drop.

Excerpt from “Farside Encounter”; collected in the anthology Tall Tales of Trade, 49.95