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Say you have an interstellar spacecraft packed full of advanced technology, such as:

  • Fusion generators
  • Androids
  • A sublight drive capable of ~0.5C
  • Various robots, holograms, and other automated systems
  • Automatic medical facilities
  • Stasis pods capable of keeping a person in suspended animation for over 100 years with no side-effects worse than a couple days of feeling jet-lagged

You've also got a complex grid computing network interwoven throughout the entire spacecraft, where work from a damaged component can be parceled up and offloaded to literally anything and everything else with a CPU.

That system isn't perfect, however, and it's possible for CPU's to start failing under excessive load. For instance, asking a robot that was designed to collect trash to pick up the slack of a failed fusion confinement computer may burn out the robot's processor or cause other undesirable glitches in its normal operations (and the eventual failure of your fusion containment systems, to catastrophic effect).

Considering that:

  • Your stasis pods are critical to keeping your passengers alive (and failures can kill both quickly or slowly, depending upon exactly how the failure plays out)
  • Your company takes it as a point of pride that none of their stasis pods have ever malfunctioned in centuries (if not millennia) of space travel
  • Your company has made literally quadrillions of dollars* running interstellar charters, so cost is no barrier in terms of outfitting your spacecraft

What possible explanations are there for allowing the stasis pods to participate in the grid computing network? For instance, as opposed to building additional/redundant high-capacity dedicated CPU nodes into various parts of the ship.

(*) Value in terms of 2017 dollars is unknown, however rampant hyperinflation is considered unlikely

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    $\begingroup$ This belongs to movies.stackexchange.com under the plot-explanation tag. $\endgroup$
    – Mołot
    Commented Jan 5, 2017 at 13:05
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    $\begingroup$ It would if it was asking for an explanation specific to a particular movie or story. But that's not the question being asked, any more than this question is asking about a specific series and not simply talking generally about starships and why they might be designed with/without specific features. $\endgroup$
    – aroth
    Commented Jan 5, 2017 at 13:07
  • $\begingroup$ "No toilets" is pretty common in sci-fi movies and toilets are part of most of the worlds, whilst so narrowly defined starship is much more specific (and probably copyrighted). $\endgroup$
    – Mołot
    Commented Jan 5, 2017 at 13:17
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    $\begingroup$ @Molot This is an engineering problem, not a plot problem. It is on topic. $\endgroup$
    – kingledion
    Commented Jan 5, 2017 at 13:54

5 Answers 5

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Stasis pods would not be connected to other systems

On ships in the US Navy, computer systems are separated specifically to avoid cascading failures. The computers controlling the electronic throttle are nowhere connected to the radars. The encrypted comms system which shares radar data with other ships is nowhere connected to the encrypted comms system where orders are sent back to headquarters. If the ship has a nuclear reactor, the reactor control system is nowhere connected to anything.

Submarines have various life support systems, but as far as I can know (I'm not a submariner) they are not computer controlled the way other components are. Still, if they were, and if they are in the future, you can be sure that such a critical component will not be connected to any other system to preserve its integrity in the face of computing failures.

Just so you know, redundancy is built into each critical system. Nuclear safety computers have three independent sets of circuits, there are two throttle and rudder control computers, AEGIS radar is broken up into a bewildering variety of sub-nodes etc.

Sharing critical functions for different computing systems is simply bad design.

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From the cruise line's sales brochure...

Customer concerns arising from our practice of linking your private stasis pod into the ships central computer network are completely unfounded. They come from a misunderstanding of the ship's prioritization algorithm. It is not the stasis pods which are connected to the ship but rather the other way around. The entire functioning capacity of each of our space-going cruise liners is available to support the proper functioning of your pod while aboard.

The unfortunate incident with the Queen Emily III is a perfect example of our dedication and design. When a critical system failure threatened the ship, all unnecessary systems were routed to pod maintenance. When that was not enough, propulsion and navigation were sacrificed for the pods. The ship stopped in space and sent out a mayday. When power failed even further, crew life support was deprioritized. Rescuer's eventually arrived to find the ship floating dead in space, like the mythical Lost Dutchman, with her crews corpses still manning her bridge. Not a single passenger stasis pod was allowed to malfunction during this entire tragic event.

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They would be connected to the network, because the stasis process requires a lot of CPU processing power to keep the people alive, requiring access to backup CPU capacity.

Something in the stasis process requires a lot of processing power, maybe to keep the consciousness intact they have to run a mini-Matrix to constantly simulate the persons mental states so that it can be uploaded back into the body when coming out of stasis. This doesn't even necessarily imply any memory formation that the person would remember, maybe something like an enhanced dream state. Or it could just take a lot of monitoring (individual cell level scanning and feedback) to maintain stasis. Either way something where a lag of processing time could kill the person, so you want redundant backups.

In this case the pods would be connected to the rest of the ship's processing network for the ship to act as backups to the stasis pods, to keep people alive in case of individual pods having problems, rather than the other way around. Even with a great track record of pods not failing, it would make sense to have redundant backups in this critical system. These backups might in fact be why pods have such a great track record.

Properly engineered the pods would use the rest of the network as a backup, but would not be a backup itself (i.e. process requests only go out from the pod, not to the pod from elsewhere.) This could of course be improperly implemented (software is hard) and given that it might not come up as a problem unless you have major damage to the rest of the ship, in which case everyone is likely to die anyway, this bug might go undiscovered for some time.

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  • $\begingroup$ Perfect answer, I think. Stasis pods are the single most critical component of the ship -- theoretically a ship could be blown apart, but as long as the stasis pod has enough power and CPU, it and its precious cargo would still drift through space intact until a rescue vessel (or opportunistic pirate) picks it up. $\endgroup$
    – Doktor J
    Commented Nov 17, 2017 at 18:28
  • $\begingroup$ If you need this grid network to cause a pod failure, perhaps one of the systems programmers was drunk and accidentally coded one of the stasis pods as a waste chute or some other noncritical component. Now what should be a high priority system is getting treated as a low priority system, and other systems are sapping its power and CPU cycles resulting in one of two effects: 1) the occupant dies because their stasis was improperly maintained, or 2) improper stasis maintenance triggered the emergency wake routine and now the occupant has been prematurely brought out of stasis. $\endgroup$
    – Doktor J
    Commented Nov 17, 2017 at 18:30
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Can we agree, as SF writers, to stop extrapolating this way? What possible reason is there to think that, during the centuries we develop FTL cruise ships, we won't make a single breakthrough in computer technology? Unless your ships run on diesel engines, your computers shouldn't use today's ideas either.

We already have some of the equipment and techniques we need to make quantum computers. Do some research. Design a computer that fits into your setting.

If it's necessary to your plot for a stasis pod to fail, find a convincing way to make it fail in context. Somebody sabotaged it. An employee at the factory got fired while assembling it and "lost" a wrench. One of the kids pressed a few buttons and accidentally started the self-destruct sequence. During the ejection process, one corner nicked a loose girder, so the stasis field didn't enclose the pod completely. A reader who doesn't understand how computers work won't understand how a CPU overload affects an escape capsule.

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This is just plain silly. Computer CPUs simply do not fail because of overuse in today's primitive technology. It is a fact that all CPU are running at 100% capacity at all times including the one you are using to read this. It is the operating system that will interrupt the "Idle" process so you can use the computer as you want. However, the Idle process is not idle, only computer code that repeats over and over again, but the cpu is still running commands while it is on. CPUs overheating and failing only occur when it is running outside of its design parameters such as when overclocked or placed under water. In reply to the comment: Yes, CPU are not using 100% of all resources that are available all the time. However, CPUs are executing a command all the time. In the comment, the HLT command is a command that the CPU is executing until the next command, interrupt, is sent. What I'm saying is that the CPU is always running as long as the computer is on.
In the scenario, each CPU is running more instructions than normal. That would mean that the CPU is releasing more heat than usual. This is why in my office, the computer room has its own air conditioner running even in winter. So if heat is an issue, the engineer would have to deliberately place CPU is an environment that would cause it heat failure. However, properly engineered overuse would not cause heat failure.

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    $\begingroup$ Well, I just did 'top' and my CPU usage is 19.1%, so I doubt many readers are at 100%. When a system idle process is running (with the remaining resources), it is just executing the HLT instruction. So the CPU isn't doing any actual computation when it is halting, and this is specifically used to cut power usage. So, you aren't right to say that 'all CPU are running at 100% capacity at all times'. But it is true that a lot of big servers are running at near full capacity for months or years, so your premise is still accurate. $\endgroup$
    – kingledion
    Commented Jan 5, 2017 at 16:08
  • $\begingroup$ @kingledion You are right, cpus idle. But cpus can also be fluidly overclocked. There could be such a system that could for short bursts push the overclock above the heat sink capabilities. If sustained it could cause the cpu to start producing errors $\endgroup$
    – Andrey
    Commented Aug 10, 2017 at 19:36
  • $\begingroup$ @Andrey why wouldn't there be thermal sensors and governors (much like those that exist in modern day consumer and enterprise CPUs) that, if the overclocking is resulting in higher-than-expected die temperatures, the speed is throttled back until the processor cools down again? $\endgroup$
    – Doktor J
    Commented Nov 17, 2017 at 18:24
  • $\begingroup$ @DoktorJ I think intel's recent issue with their micro-code shows what can happen... Yes the CPU has a thermal sensor/governor to monitor it, but that is code written by a person and people make mistakes. $\endgroup$
    – Questor
    Commented Oct 4 at 23:49

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