45. Hyperspace Navigation

The final report came from Major Dora of the Exploration Division.

"Previously, manned hyperspace navigation had an error rate of 0.1 percent. We now have a clear path to reduce this to one-fortieth of that—matching the performance of unmanned vessels. The outbound journey of twelve thousand light-years took twelve years, but the return trip will now take only a quarter of that—just over three and a half months."

The sudden bombshell left the conference room buzzing. After the murmurs subsided, Major Dora continued.

"Currently, Agirakana navigates hyperspace with an error margin of 0.1 percent—equivalent to traveling at a thousand times the speed of light. If we exceed current speeds in hyperspace, the moment we jump out and re-materialize in real space, the sudden risk of missing essential factors for restarting organic life functions becomes alarmingly high."

While in hyperspace transit, we are unobservable from real space, meaning our existence can only be described in probabilistic terms. These probabilities fluctuate constantly, element by element—but once the margin of navigational error surpasses a certain threshold, the fluctuations in elements essential to life activity spike abruptly. That threshold—currently set at 0.1% navigational error, or one thousand times the speed of light—marks the point of no return.

Increasing our velocity amplifies these fluctuations, and with it, the probability of essential life elements stabilizing approaches fifty percent. At the moment of jump-out, our survival becomes a coin toss—fifty-fifty, at best.

To stabilize this fluctuation, we applied advancements in stabilization technology originally developed for transfer destinations, successfully creating a stabilization field that suppresses the probabilistic drift of our presence during hyperspace travel.

Currently, since Agirakana is in hyperspace transit, we are not conducting verification experiments, so we cannot guarantee a one hundred percent safety or certainty. However, we would like to gradually increase the vessel’s speed from one thousand times light speed—equivalent to the current navigation error of 0.1 percent—over the course of one month, aiming to reach the maximum jump drive speed of four hundred thousand times light speed, with a navigation error of 0.0025 percent, if you would be so kind as to approve?

“Even in the case of unmanned units, the primary equipment consists of precision components—would such items be unaffected?” someone asked.

“Even in unmanned units, the AI systems, being ultra-precision instruments, are affected. However, during jump-out events, the internal autonomous repair programs maintain functionality. Therefore, as things stand, increasing the number of jumps does carry a slight risk of unmanned units being lost.”

No, that’s troublesome too. If it fails, I’m probably going to vanish entirely—existence probability zero, stuck in hyperspace. Whether it happens at the moment of jump-out or while accelerating, I can’t say. But either way, I won’t be aware of it. I’d rather not disappear entirely—especially not with Agirakana. Then again, Agirakana isn’t a lifeform, so maybe it’ll survive. Honestly, I can’t tell.

“Is the safety protocol simply to monitor the situation and gradually increase speed?”

It’d be better if there were a more concrete safety measure, but I suppose that’s the only one available.

“Since this technology was originally developed to solve the re-emergence problem associated with extended transfer distances, we’ve judged it to be highly safe.”

I’d always assumed I’d been deliberately restricted from long-range transfers. Didn’t realize it was due to some complicated technical limitation I hadn’t known about.

From a procedural standpoint, one ought to confirm safety concerns, at the very least.

“Is it possible to revert back if the probability of essential elements for current life activity becomes unstable?”

“Since the stabilization process of fluctuations is a reversible one, reversion should be straightforward—simply return to the original rate.”

The Exploration Division seems quite confident. Perhaps this is worth the risk.

“Then, as Major Dora of the Exploration Division, you’re suggesting we proceed. Anyone else have an opinion?”

“Major Dora says it’s safe—shouldn’t be an issue,” said Lieutenant General Amanda.

No one else seems to have objections. This person places strong trust in their colleagues—something I expected, given their demeanor.

“Since no one else objects, let’s go ahead. Major Dora, when can we begin?”

“The stabilization field generator isn’t particularly complex, but since it needs to cover the entire Agirakana, it’ll be a large-scale unit. Still, we can have it built within a week. Including the observation apparatus for measuring fluctuations in existence probability, the feedback mechanism for the jump drive, and other components, we’ll need about two weeks to complete preparations.”

“Major Dora, once everything is ready, begin accelerating Agirakana’s hyperspace navigation at an appropriate time. Everyone agrees with that, correct? And Major Dora, no need to report the start. If it fails, I’d rather not know until it’s already gone.”

“Understood.”

“This meeting is adjourned.”

The meeting ended—but Lieutenant General Eris of the ground forces called out to Major Dora, halting her. Major Dora answered the question.

“…in that case, if we lose the fifty-fifty gamble at the moment of jump-out, we’re not just ceasing biological activity the instant we transition into hyperspace—we’re being retroactively erased, causality forcibly rewritten, and our very existence, including that of Agirakana, simply unmade.”

It was starting to sound like philosophy. After listening for a while, I decided I couldn’t grasp it and stopped trying. In any case, I’d take comfort in the fact that, if things went well, I might be back on Earth in just four months or so.

Fifteen days had passed since the meeting. Given that hyperspace navigation should by now have been accelerated, and since I was still here—still breathing, still thinking—it seemed the stabilization field had, at least temporarily, succeeded.

I hadn’t asked exactly when the stabilization field had been activated, so I couldn’t say for sure, but it was probably just over a month since activation. A report had come in from the reconnaissance division: hyperspace travel speed had increased fortyfold, with no apparent issues.

Fourty thousand times the speed of light. Arriving at the two-light-year mark—where Agirakana had been located—just twenty-seven minutes from the Solar System. Still, much like the hyperlane gates, hyperspace jumps affect planetary navigation within star systems, so it seems transits must occur beyond the outer edges of a system. From Earth, that means it takes more than half a day just to reach the jump point.

For the one-month period while hyperspace travel stabilized, life was passed pleasantly—novels, fishing, hot springs, and banquets. A lifestyle of early retirement, envied by all, reserved for the wealthy who’ve cashed out.

Three months until we return to the Sol System. Despite having a novel half-finished, I’ve been assigned the task of naming the light cruiser LC-0002—something I’d rather not see go down like a Fūrinka. So I considered “Turtle,” imagining a crane that lives a thousand years, a tortoise that lasts ten thousand, but then thought: a light cruiser named for a slow-moving turtle? Unlikely. So, I settled on “Crane,” even though the crane’s lifespan is reduced to a tenth of that. Still, it’s a crane—here, it’s the crane.

Light Cruiser LC-0002—Crane. The name “Crane” might bring construction-site cranes to mind for Japanese people, but here, it’s the crane.

Then there’s B.C.-0001. The first battleship ever built by Agirakana. A battleship could also be called a fortress of black iron—how about S6-class battleship B.C.-0001, Citadel? It’s a hull ship, so it won’t actually look black, but rather white—let’s overlook that detail. We can only hope it lives up to its name, Citadel, and is as solid as a fortress.

As always—half-understood, half-pretended—apologies for the usual convenient logic.