“If these were real operations, Natural Selection would now leave port. What do you think? Simpler than spaceship operations in your day?”

“Yes. Much simpler.” When he and the other special contingent members first saw the interface, they were surprised at its simplicity, and the total lack of technical detail.

“The operation is totally automatic, leaving the technical process entirely hidden from the captain.”

“This display only shows general parameters. How do you see the ship’s operational status?”

“Operational status is monitored by officers and noncommissioned officers at lower levels. Their displays are more complex—the further down you go, the more complicated the interface becomes. As captain and vice-captain, we must focus our attention on more important matters.… Very well, let’s continue. If I were Imprinted … There I go with that supposition again. What do you think?”

“Given my position, any response would be irresponsible.”

“Fine. If I were Imprinted, then I’d set the throttle directly to Ahead Four. No other ship in the fleet can catch Natural Selection under Ahead Four acceleration.”

“But you couldn’t do that, even if you had the permissions, because the system will only proceed to Ahead Four if it detects that all passengers are in a deep-sea state.”

Under maximum propulsion, the ship’s acceleration could reach 120 gs, but this exerted a force more than ten times what a human could tolerate under normal conditions. To go to maximum, they had to enter a “deep-sea state,” which consisted of the cabins being filled with an oxygen-rich “deep-sea acceleration fluid” that trained personnel could breathe directly. As they breathed, it would fill their lungs and then the rest of their organs. First dreamed up in the first half of the twentieth century, the liquid was intended at the time to facilitate ultra-deep dives. Pressure was in equilibrium inside and outside of a human body filled with deep-sea acceleration fluid, meaning it could sustain high pressures like a deep-sea fish. The environment of a liquid-filled cabin in a rapidly accelerating spacecraft was like that of the deep sea, so the liquid was now being used to protect human bodies against the ultra-high acceleration of space travel. Hence the term “deep-sea state.”

Dongfang Yanxu nodded. “But you should know that there’s a way to get around that. If you set the spacecraft to remote control, then it will assume that no one is on board and won’t perform the check. This setting is part of the captain’s permissions.”

“Let me try it and you tell me if I’ve got it right.” Zhang Beihai activated an interface in front of him and began setting up remote control mode for the spacecraft, looking at a small notebook from time to time as he did so.

Dongfang Yanxu smiled at the notebook. “There are more efficient recording methods now.”

“Oh, it’s just habit. For particularly important things, it’s always more reassuring to write them down like this. It’s just that I can’t find a pen now. I brought two with me into hibernation, but only the pencil was still usable.”