Our space ship has lost power, what happens now....

[Melbourne Guy]

I'm about 25,000 words into my latest novel and the story arc is coming together nicely, but one aspect I need thoughts on please is what would happen inside a spaceship that has been grievously damaged in battle to the point that it has been abandoned by the fleet as a 500m long wreck.

Specifically, there is no power so the only light is from emergency globes and there is no gravity (my novels have AG), and I am wondering what happens to the air?

I'm assuming that in zero gee it would need fans to circulate, but does that lead to adverse effects on the few crew who survived? Or would it not matter much, as the ship's heat drains away and the crew freeze to death...

 

[Filip Larsen]

Over how long time are you considering and what kind of (long term) effects are you looking for? Surviveability for any crew on-board or the possibility for an external crew to repair the wreck at some point?

I would imagine it also could make a significant difference whether or not the internal parts experience internal acceleration gradients due to abnormal rotation (speed or axis), or due to close orbit around a planet. And of course, if there were any internal systems that would have a long term "failure mode" that would be accelerate the process, e.g. nasty chemicals that slowly leak out to corrode the pressure hull or similar.

 

[anorlunda]

lead to adverse effects on the few crew who survived? Or would it not matter much, as the ship's heat drains away and the crew freeze to death...

If there is no rescue, then the crew must die. Who cares what the mechanism is? It could be merciful to open the hatches to the vacuum and stop prolonged suffering.

 

[Melbourne Guy]

Over how long time are you considering and what kind of (long term) effects are you looking for? Surviveability for any crew on-board or the possibility for an external crew to repair the wreck at some point?

Plot spoiler, the crew will be rescued from an unexpected quarter after seven days adrift! But good questions, @Filip Larsen, my current thought bubble is that the crew are suffering from environmental system collapse over a period of about eight hours before they restore limited air circulation in a small section of the ship. But writing this reply, the time frame seems too short, I might have to add in a leak to amp up the tension

It could be merciful to open the hatches to the vacuum and stop prolonged suffering.

The captain thinks along these lines, @anorlunda, but does not give into despair sufficiently to action it, though it is doubtful she ever would, she's a strong character.

 

[Filip Larsen]

the crew will be rescued from an unexpected quarter after seven days adrift

7 days does not sound like long. Even if the crew don't know they are going to be rescued it seems prudent to try and survive for as long as possible and only near the end end it quickly if no way out is found. If the ship was designed for battle I assume it would be sensible that there are multiple decentralized redundancies on vital functions such as energy and environment control, but even if that all fails even a sizeable crew should be able to survive for some time in a close air volume with the increase in carbon dioxide being the expected route to an unpleasant death as it under normal circumstances happen before lack of oxygen which is not experienced as unpleasant (lack of oxygen partial pressure is a real hazard in aviation because it is very difficult to realize, in contrast with too much carbon dioxide).

If you have an estimate on the average volume of air per crew member it should be possible to calculate the likely time before carbon dioxide poisoning sets in.

(Edit: my keyboard works terrible today)

 

[Algr]

If there are hot and cold areas of the ship, that could still cause air circulation. And if the ship is big enough, microgravity could still exist. So cold air from the outer walls would slowly make its way to the center of the ship, displacing lighter warmer air. Shutting internal air vents would slow heat loss.

 

[Filip Larsen]

If there are hot and cold areas of the ship, that could still cause air circulation.

If you are thinking about convection then that requires induced weight by gravity or acceleration.

 

[Algr]

Microgravity from the weight of the ship itself.

 

[DaveC426913]

Microgravity from the weight of the ship itself.

Not sure that will work. Newton's shell theorem suggests that gravity inside a mass should be effectively zero.

 

[Filip Larsen]

Microgravity from the weight of the ship itself.

Microgravity due to gravity on the surface of a spherical ship with an average density around half that of water is comparable to the centripetal acceleration from the ship rotating once per 9.3 hours, so microgravity due to mass of the ship is a very tiny effect that is drowned out by pretty much any kinematic motion or low orbit gravity gradient, and I have a hard time imagine this could drive "natural" convection alone. The reason I say all this is because the term "microgravity" is usually applied to mean "microaccelerations".

But granted, at some amount of rotation and some amount of temperature gradient it may be that some convection sets in. Could be interesting to know the lower limits for rotation rate and temperature gradient one can expect the onset of a stable air convection cell.

 

[DaveC426913]

My high school physics tells me that different gasses disperse independently, per their partial pressure.

In other words, without gravity, CO2 and O2 will spontaneously diffuse and mix. This means - as long as there is enough volume - you don't have to worry about "pockets" of gasses collecting in corners or surrounding breathing crew.
A crewman huddled in a closet (with the door open) won't find himself suffering from low oxygen or CO2 poisoning any more than anyone else in the room.

 

[Klystron]

You might receive writerly inspiration from the long SF story "The Stars, My Destination" written by Alfred Bester. Protagonist Gulliver Foyle survives aboard a ruined derelict space freighter becoming consumed with revenge.

The details of the story are unimportant to your plot but the descriptions of his predicament and the changes wrought on the character remain classic.

 

[Melbourne Guy]

Thanks for this discussion, my plot reflection from your thoughtful comments are:

1. I need to extend the period the crew spends waiting for rescue, a week is too short, not enough will happen to trigger the tension I need.
2. CO2 build up, which was my assumed enemy, won't be a real issue in a ship this large (it's 500m * 200m * 125m in rough dimensions) given only 132 crew members survived and a third of them are incapacitated so die before rescue arrives, and I appreciate the clarity on this.
3. Heat loss is an appropriate enemy. The temperature slowly dropping is a solid motivator for the action in this portion of the novel.

And @Klystron, I read The Stars, My Destination many (many many) years ago under the Tiger! Tiger! title, I recall it was quite dark in tone, but not much else!

 

[DaveC426913]

I need to extend the period the crew spends waiting for rescue, a week is too short, not enough will happen to trigger the tension I need.

Well, if the captain ordered them all into spacesuits out of fear of a blowout, they'd get pretty cranky pretty fast.

 

[Melbourne Guy]

Well, if the captain ordered them all into spacesuits out of fear of a blowout, they'd get pretty cranky pretty fast.

There will be some suit wearing, @DaveC426913, so 'cranky' will certainly occur

 

[Algr]

A spaceship is naturally well insulated by the vacuum of space, so heat loss would likely be quite slow. At Earth distance from the sun, a derelict ship might get hotter instead of colder. Also, if they have technology for spaceships, they probably have super-batteries to power personal heaters, fans, radio-phones, and carbon de-oxygenators. For a long wait, sleeping bags might be better than space suits. These could be designed to protect against blowouts and be quite comfortable.

I can ruin anyone's ideas!

 

[Melbourne Guy]

I can ruin anyone's ideas!

You can, except the ship has just survived two devastating alien attacks, @Algr, one of which involved a particularly unorthodox 'hard reverse' that applied thirty-gee to the spine, so it's been shattered and all the high-tech toys are either broken or malfunctioning. At least, that's my story, and I'm sticking to it

 

[Filip Larsen]

If many of the ships systems has been broken as a result of alien weaponry then it seems plausible to have a leak of some more or less toxic working fluid or gas from such systems into breathable air. Something that by design would not pose as serious problem during normal operation, but in your scenario can be allowed to slowly escalate into an problem unfixable by the crew by the time they finally become aware of it. Challenge is to find a suitable system.

Propellants are often a likely candidate for toxicity in association with spacecraft s, but assuming most tanks and similar are situated outside the pressure hull some of it somehow needs to "slip in". Since the ship is big perhaps it has a small transport sitting in hangar that can be banged up and leak?

Another candidate could be fluids in the environment control system or the thermal control system.

 

[Klystron]

Thanks for this discussion, my plot reflection from your thoughtful comments...

And @Klystron, I read The Stars, My Destination many (many many) years ago under the Tiger! Tiger! title, I recall it was quite dark in tone, but not much else!

I first read Bester's novel as the anchor story of a popular SF anthology. Dark may be an understatement. The first chapters discuss the shipwreck and set the theme of survival at all costs. Read in 1960, I mainly remembered descriptions of survival on a derelict spacecraft in an improvised suit scavenging air, power and food. The wrecked ship powers the rest of the story.

Considered by later authors the first cyberpunk novel, after rescuing himself Gully Foyle buys surgical implants throughout his body that enhance his senses and fighting ability; i.e., 'accelerate'. When I learned fighting techniques, I would think 'accelerate' to beat opponents with quickness over brute strength. Thanks.

 

[Melbourne Guy]

Another candidate could be fluids in the environment control system or the thermal control system.

I like how you think, @Filip Larsen, I've been working out what fluids might leak from a spaceship built in mid-2522. There's a lot of scope for personal mayhem in a shipwreck, which I need to work through in more detail because I've the story arc in mind, and now I just have to work out who lives and who dies.

 

[Melbourne Guy]

Considered by later authors the first cyberpunk novel...

I'd always assumed Gibson's Neuromancer was the originator of the cyberpunk concept, @Klystron, but a quick skim just now showed me the idea was developed considerably earlier and it was merely that Neuromancer was the book that entered popular culture and so 'established' the genre.

 

[Rive]

A spaceship is naturally well insulated by the vacuum of space, so heat loss would likely be quite slow.

Actually, due the insulation both cooling and heating is necessary.
I see the promise of a nice plot twist in having one of them (likely: cooling) remaining operational...

there is no gravity

As it was mentioned before, a wreck would likely tumble. So it's actually some kind of irregular gravity, but at least one which contradicts with the original and changes according to position...

I'm assuming that in zero gee it would need fans to circulate

For confined space you need that in gravity too. I don't think it would be a significantly more difficult problem at zero G, but some (manual) ventilation (waving clothes?) might be included in the story.

 

[DaveC426913]

actually some kind of irregular gravity,

Irregular gravity??

 

[Melbourne Guy]

Irregular gravity??

I'm not assuming to speak for @Rive, but I think I understand the intent regarding a tumbling spaceship, @DaveC426913. I used it in a previous novel, the protagonist had trouble working his way into a portion of a ship that had been damaged by sabotage because of the off-axis (to the original ship design) spinning.

 

[DaveC426913]

Oh, you meant wrong direction. I thought you meant variable.

 

[DaveC426913]

As it was mentioned before, a wreck would likely tumble. So it's actually some kind of irregular gravity, but at least one which contradicts with the original and changes according to position...

This gave me pause for thought, and might be relevant to the OP, so I brought it up in the physics subforum.

 

[DaveC426913]

Yeah, this came to mind, but at first I didn't think how it might shed light on the question.

But the more I think about it, it would make an amazing plot vehicle. Imagine the ship seems to be in a stable spin through its long axis, and then spontaneously flips end-over-end!

By the way, this phenomenon came up in another recent thread about spaceships. @Filip Larsen goes to great lengths to demonstrate that such a ships rotation would be unstable.

 

[Melbourne Guy]

But the more I think about it, it would make an amazing plot vehicle. Imagine the ship seems to be in a stable spin through its long axis, and then spontaneously flips end-over-end!

Absolutely, thanks @DaveC426913, I'd never heard of this before, it's certainly intriguing and I'm already musing about how it can be introduced to good effect...but without the equations

 

[Klystron]

I'd always assumed Gibson's Neuromancer was the originator of the cyberpunk concept, @Klystron, but a quick skim just now showed me the idea was developed considerably earlier and it was merely that Neuromancer was the book that entered popular culture and so 'established' the genre.

I agree. Gibson established consistent themes of cyberpunk with "Nerumancer" and "Wintermute" including distinctive music and clothing, 'cool' drugs and computers, implants and electrodes, while borrowing from predecessor novels.

Consider 'razor girl' Molly from "Neuromancer". Her reflective eye shield implants mirror the partial blindness of several female characters from "Tyger". Robin, blind from birth but a powerful telesend; Olivia, blind to visible light but able to 'see' infrared down to radio frequencies; and the enhanced cyborgs sensitive to heat/infrared radiation.

I imagine some characters among your crew sport cyber enhancements plus built in life supporting gear such as emergency oxygen and RF transceivers.

 

[Filip Larsen]

Indeed, the term tumbling in the context of roation is usually taken to mean non-pure rotation, i.e. a rotation that, depending on the exact rotational state and mechanical properties of the rotating object, potentially can give a lot of variable internal acceleration. For instance, loose objects inside a tumbling spaceship may experience to be "thrown around" all the time. I imagine that random rotation-inducing impacts during combat would be able to leave a spaceship wreck fairly impossible for the crew to move around in right after combat due to tumbling, however the tumbling will over time decay into pure rotation even for a fully passive shipwreck due to internal friction from fuel sloshing and elastic bending of internal structures. In fact, it is not uncommon that spin-stabilized satellites today contain nutation dampers to help maintain pure rotation.