How might derelict space ships/stations be only partially salvageable?

Question

My setting is a fantasy where the average space-trekker subsides on scrapping derelict ships from a distant golden age in the past to maintain their own, with only the corporate rich being able to afford new construction nowadays. I may use some hand-waving for the setting since it is fantasy (e.g. space is a lot less empty than it ought to be), but I would like the denizens of the setting to plausibly and consistently play by the laws of this universe that's otherwise the same as ours.

For the setting, I would like scrappers to have to work for their salvage (and specifically have to do a lot of repairing). Unfortunately, while some derelicts may be badly damaged by warfare and similarly catastrophic events, there are also derelicts that would otherwise be in great shape:

• The former crew ran out of oxygen/sustenance and perished without any damage to the ship
• The former crew had a falling out and killed each other with small arms, leaving only minor damage to the ship
• Due to a loss of crew, the crew could no longer afford to maintain a few of their ships and had to abandon the fully functional ships on the way back to station
• Pirates boarded and robbed the ship, killing the crew and taking their valuables, but left the rest of the ship in decent condition (e.g. don't have enough manpower to add the ship to their fleet, or it's just not worth their time when they are more efficient taking only the valuables)

Is there any plausible explanation why even these derelicts might be in largely poor condition (but still partially salvageable with repairs) after say 1000 years? Note: I am trying to separate this from previous scrappers scrapping derelicts dry. This will certainly happen, but when you do come across something that hasn't been taken already, I'd like for it to be broken and not in mint condition.

Chemicals: Chemicals like fuel / medical concoctions are easy to degrade due to chemical reactions (e.g. shelf life of hydrogen peroxide), but this gives me the opposite problem where it might be implausible to find usable fuel / medical supplies on any derelict (I'd like them to be rare. Not impossible)

Electronics: Electronics use chemicals like in capacitors, so it's easy to justify their degradation like above, but again this might make it implausible for any 1000 year old electronics to work

Inert objects: It's beyond me how some inert object like a metal chair would degrade in space over time to the point of requiring repair. In an Earth-like setting it's easy due to rust / overgrowth / etc, but none of that exists in space.

And the more flexible the reason, the better. For instance, something that allows for 5% of some arbitrary electronics in a ship to survive is preferable to only a specific brand/model of electronics which avoids certain chemicals surviving.

Answer 1

Normal degradation outside of micro/meteoric impacts in most materials will be retarded in space. This applies mostly to those materials that exposed to vacuum and cold. However many components and systems within the whole of the ship may suffer from degradation over time anyway. We often hear about how conventional Wet Navy nuclear carriers can stay deployed for 20 years before refueling. however in reality they spend only about 1/3 of the time deployed. As much as it is in active maintenance. This of course is not a wartime situation.

Many operations must take place to keep the craft from degrading. Much more for the far more complex space going vehicles in the OPs description. without replacing filters or consumables systems are affected. Ultimately all systems are connected and when one goes down, there is likely a consequence another is impacted.

Liquids/powders/gasses for:

• Lubricants
• Coolants
• Hydraulics
• Propellants
• Caustic cleaning agents
• Munitions
• Human Consumables
• Waste Byproducts
• Radioactives

All are carried and stored aboard ship. Over time seals leak/break or degrade, sometime much faster if exposed to cold and vacuum when they are not meant to. Simple water freezing can cause explosive damage to structures if a container that was not meant to be frozen is. chemical can be corrosive even in dry forms to circuit boards and displays. Capacitors and batteries can leak. Some chemicals absolutely must be stored under specific conditions or cause "problems". So just the long term loss of power can be an issue.

The space environment is not just cold and vacuum. UV damage to plastics, if used at large over the construction could be extensive. In the movie 2010 it was quite impressive they included the buildup of sulphur compounds on the hull of Odyssey from the volcanic eruptions on the Jovian moon Io. long term exposure to solar winds or cosmic rays could be death to any electronics absent active shielding. And unknown effects on plastics, organics and polymers.

Answer 2

1000 years in space take a toll on anything: constant bombardment by space dust traveling at several km/s plus the particles contained in the stellar wind will deliver a noticeable cumulative damage, which is topped with the thermal excursion between illuminated and dark side.

Electronic in particular is very sensitive to ion bombardment. 1000 years of it won't be kind on any electronic device.

Moreover mobile metallic parts with unsufficient lubrication will end up being cold welded, which is rather incovenient if for example happens to a joint which is supposed to move.

Answer 3

Economics is the key

The main reason any wreck that might be found hasn't been salvaged centuries ago is that no one could afford to do so. Some parts are more expensive than others -- engines and computers at the top of that ladder, hull plating and airtight doors lower, interior structure like wall and deck and overhead panels (lightweight but still strong enough to hold air pressure) along with wiring, plumbing, fixtures, etc. lower than those, and common stuff like furniture, fossilized foodstuffs, etc. aren't even worth hauling to the airlock.

However, getting to the wreck is expensive, too. Someone had to front the value of the fuel, at least promise to pay a crew, do some minimum amount of maintenance on the salvage vessel -- in other words, what you get from a wreck isn't free if you figure in all the costs of "doing business."

And a lot of what's left after a thousand years isn't worth the cost of getting to it. Salvage is an edge-of-bankruptcy job, much like wildcat oil drilling -- those who make a big strike can get seriously rich, but most of the drillers (or captains) are half a step ahead of the bill collectors, and wouldn't be that far if their equipment had more resale value.

Answer 4

Water damage

Now hear me out: On these ships, the life support systems were left running. That means, among other things, that the air contains moisture which can degrade metals.

But more than that: there have to be pipes throughout the ship carrying water. And a pipe breaking in all that time is not only possible, but even likely. Without a crew to fix this, you'll get flooding in any part of the ship you (as the author) like, and any resulting damage.

You could even have a spill in a bio lab, or the pantry, which lets seeds germinate and grow, eventually throughout the ship.

Imagine the salvage crew wading through a field of wheat...

Answer 5

Not their first rodeo

Just because a ship is a) derelict and b) 1,000 years old doesn't mean it's been adrift for 1,000 years. Indeed, except when people go out of their way to hide them, shipwrecks in space aren't all that hard to find, and if you know where the big battles took place or where the shipping lanes were that pirates preyed on, you could snap up most of the wrecks much quicker than that.

So people did, and because spaceships are valuable, the wrecks were refurbished and pressed into service. They were, as you imply, mostly salvageable - but mostly isn't 100%. Because of damage, exposure to varying environments, scarcity of replacement parts, or just the whims of their new owners, there were usually some bits somewhere that needed to be patched or jury-rigged. And when misfortune befell these salvaged ships, they were salvaged again, and again there were parts that needed to be replaced with something non-standard.

Continue this process for centuries, until you've got spacelanes full of Ships of Theseus - allegedly, they're the same thousand-year-old vessels they always were, but repeated salvage and maintenance means that any given component might be a genuine centuries-old Golden Age relic, a cheap patch job hacked together a week ago, or anything in between. It's very rare that you find a complete, or even mostly complete Golden Age ship; it's the kind of thing grizzled old space prospectors tell stories about in dingy space bars, but few if any of them have ever actually seen one.

So the answer to "why are these derelict ships broken-down, partially salvageable wrecks with only a few good components remaining" is - that's what they were like before they went derelict (the most recent time), too. Good-quality wrecks are rare because good-quality ships are rare.

Answer 6

A few things:

1. Space is stunningly hard on things. This has been mentioned before, but I think it's worth explaining in more detail. Space is so hard on things that part of what limits a mission's lifetime nowadays is how much space eats away at the materials. The shuttle even ran an experiment about it called the Long Duration Exposure Facility, whose purpose was to literally bolt materials onto a base and leave it out in space for years to see what happens. Check it out. Space also makes things undergo tons of thermal shocks: orbiting from sunlight into shadow, or just generally having one side of the ship exposed to sunlight and the other not. This is why the apollo missions did a "Barbecue Roll", an approximately 1 revolution per hour roll to ensure that no one side of the spacecraft got too hot or too cold.

2. Let's say I got you a computer from even ten years ago. You're super pumped to get the data off of it but...wait...there's a password? If we're talking about the future, it is very plausible to believe that unbreakable passwords and access codes simply prevent access to certain components. Only the long-dead chief engineer could access the Chamber of Shocking Radioactivity in the engine room, and no amount of tinkering will get it open without killing you. This would be especially true of the weapons

3. The ships were designed so that, if they were abandoned for too long, their major components would melt into slag. Wouldn't want the enemy salvaging important stuff, now would we?

Answer 7

The parts act like they're alive:

This can either be literal of figurative. The parts are held in a complex conformation that needs constant power. Like a cell "dying," the programming and continuous operations of the part collapse once they are no longer kept alive. Once the crystal matrix/chemical configurations/whatever collapse, it's easier to make a new part than to get the old one to work. So they die and are now only good for recycling.

But the parts don't need MUCH power, generally. A part with an internal battery can keep it self in a low-power setting for centuries. Parts connected to a resting but functional engine may stay alive indefinitely. So parts may die or not depending on damage, how much the batteries were drained before being abandoned, age, and if they are close to the engine or power conduits. Simple parts may even be able to "hibernate" indefinitely if shut down in the right way (which is rare if you're abandoning ship).

Answer 8

Ships have self repair functions

Ships have maintenance nanites and droids, which can perform basic repairs and fix minor issues. Over hundreds of years though, they degrade and fail. Many ships only have the nanites and droids left to repair a small number of objects.

Ships failing often has destructive effects on other parts of the ship when random parts float around and smash into things, or volatile chemicals mix together and explode. This can cause damage to ships.

Skilled scavengers know where the best salvage spots. The bridge, or the captain's room or engineering may have a higher nanite priority and have more lootable goods, depending on the ship model.

Answer 9

Because of creepy, aggressive alien critters

You said that your world is more Scifi than hard science fiction. So it would be plausible that there is some form of HR Giger Style, non-sapient, aggressive, alien species which tends to nest in abandoned space ships. Their presence makes it very risky to board ships which were abandoned for too long. If you have a squad of well-equipped, trained and expendable space marines, and if you are looking for something very valuable, then you might risk an expedition. But any common space salvagers would need to be very brave or very stupid to board a space ship that was abandoned for longer than a couple month.

The presence of the aliens could also damage the ship beyond use, so it might not be worth it to salvage a ship that was infested by aliens, even for one with the means to remove the infestation.

Answer 10

Not all ships wrecks are >1000 years old

First of all, if you find a ship that has not been touched in 1000 years, it's going to be little more than scrap metal. Cold-welding and chemical degradation will ruin pretty much all of the technology on board. Other answers go into more details on that, so I won't. However, you are missing the fact that not all ships you find will actually be 1000 years old.

...with only the corporate rich being able to afford new construction nowadays...

You say it yourself that new ships are still being made; so, if you get lucky, you might come across a ship that is only 100 or even 10 years old. While these ships may be made in way smaller numbers compared to how many ships were manufactured 1000 years ago, they will still make up a surprising ratio of the derelicts by virtue of the fact that the 1000 year old ships have already mostly either been salvaged or fallen into a star or planet or drifted off into deep space where they are harder to find, etc.

More over, if scraping and restoring ships is a viable occupation today, then it stands to reason, it's been a viable occupation for the entire past 1000 years. So, you may find a mostly functional hull of a ship design that has not been produced since the golden age, but that does not mean its been there for 1000 years. Maybe someone like yourself found it 200 years ago, restored it, and continued to use it until 50 years ago when it was lost to space again.

So by combining these factors, it will still be possible to find a derelict ship, even a 1000 year old design, with some but not all intact systems even if having systems survive for 1000 years is not viable.

Why most ships are worth scraping instead of restoring

This is a simple matter of supply and demand. If your market becomes saturated with old broken down ships that barely function because so few people can buy new ships, then the value of a few choice scrap pieces may be greater than a whole used ship. The parts of ships that last the longest are worth no more than the metal they are made from, but things that fail more easily: computers, propulsion systems, power systems, etc. These will be worth a lot as salvage, if you can find any in working or near working order. Compare this to old cars. An old car may only be worth 300\$ at a junkyard, but if the transmission is still pretty new, and someone else needs that exact transmission to fix thier own car, they may actually end up paying 3000\$ for just the transmission because it is hard to find and it's in good condition. Even a refurbished transmission that did not work when you found it can be worth well over 300\$. So, because the sum of a derelict ship's parts are worth more than the whole, it makes since to only take what is worth the most and save the cargo space by leaving most of it behind.

Answer 11

Extreme biohazard risk

A wreck in space is a surprisingly good place to accidentally produce a super-germ.

Each of these space derelicts was inhabited by living people, and they brought their germs with them. They also brought heat and food and moisture. When they died, their germs did not. And unless the hull was ripped open, exposing the entire cabin to sterilizing radiation, those germs had the run of the place.

Just as importantly, the wreck is a time-capsule that contains a collection of germs that were proven effective against humans when it was launched -- germs that contemporary society may no longer be equipped to defend against. Imagine if somebody in the real world dug up an ancient treasure chest filled with ancient coins and smallpox -- a disease we eradicated a while ago.

Opening a wreck in space is like foraging for a snack in a college dorm refrigerator, and the rules are exactly the same:

• avoid anything that's covered in fuzz
• avoid any pools of liquid or weird stains
• assume that anything is deadly whose container is not sealed air-tight
• don't let your skin touch anything other than the one item you decide to retrieve
• if something is sticky to the touch, drop it and go wash your hand with soap
• when you exit the wreck, meticulously sterilize the exterior of your suit before you come into contact with your own vessel or other crew
• enter your vessel only through the special biohazard airlock
• spelunking suits are meant to be disposable: when a suit's lifetime "yuk exposure" reaches 7, discard the shell in space and then incinerate the inner lining as soon as you take it off

The safest parts of a wreck are the parts that were cleanest and driest when the vessel was operational. Avoid the crew cabins, mess, latrines, showers, bridge, and rec rooms. Start with the exterior equipment, engineering spaces, and large internal machinery.

Cargo bays are a real crap-shoot. Cargo values are obviously highly variable, but so are the hygiene rules of each crew: some ships treat the cargo bay like a high-security property room, others treat it like a shared multi-purpose space. So, some bays will be clean, others filthy.

Every space is off-limits that contains a corpse or substantial amount of food or biomatter (or evidence of same). Yes, this does mean that if you're removing a fuel pump from the engine room and you discover an "empty" candy bar wrapper, everyone in the engine room must immediately (and calmly) set down/release any parts they are carrying, exit and seal the room, and call for a supervisor. Depending on the supervisor's assessment of the room, everybody who was in there needs to add some "yuk points" to the mental tally they keep for their suit.

Answer 12

Heavy hulls

There was a brief period when energy was abundant and allowed to bring into orbit thick and heavy parts used to build the space stations external walls. Not only they were safer in case of impact by meteorites, but they shielded the occupants from the gamma ray. But the frantic energy consumption ended with a sudden collapse stopping all space operations, except for small satellites, for a long time, the stations were abandoned because resupplying them was too expensive.

When space colonisation restarted they remained unused because they were in the wrong orbits to be useful and too big and expensive to repair and refit. The economy begins to improve when we get to the age of your story. The internal electronics and life support systems will degrade in time, but those thick hulls with heavy gamma rays shielding are still extremely valuable. The scavengers will have to check whether the welding on the outside have no cracks and rebuild the inside. Trouble is that the rigid walls withstand easily impacts by micrometeorites and meteorites up to a point, then they crack badly whether it will happen is just matter of chance.

Answer 13

Spaceships and space stations must, above all else, keep their insides inside and the outside outside. Suppose you find one in working condition floating around, uninhabited; it may be very valuable to you if you have a way of getting inside it without damaging it, but if you break anything on your way in then it'll be junk. And, being valuable things, the locks on them are pretty secure.

A broken hull leaks, letting the vacuum of space in, and only the rich galactic elite have the resources to fix that sort of thing properly these days. But even if you find a spaceship with its hull intact, it won't be for long, because you need a tin-opener to get into it.

Answer 14

The question implies that wrecks that are available for salvage are mostly military construction and most often would be a part of old battle space.

Question: what was the basic rules of space warfare? I mean: armies fight over objectives. Empty space has nothing to fight over...

If this is the case of mostly intra-system combat (loosely speaking, of course), then the derelicts would be concentrated in star systems, probably more around habitable planets or, if whole system is not suitable for colonization, then strategically important locations (which should be much fewer).

Following this option logically, it is quite possible that most of the wrecks will be either captured by space bodies' gravity fields, either in orbit or straight up pulled down to the surface. Then, depending on option they would more or less wrecked by conditions. Problem solved.

If that would not be the case and you'd stick to deep space as main source of wrecks, then it is difficult to introduce extensive damage, indeed. But not impossible, because solar winds, all kinds of radiation and of course space dust will degrade anything over a millennium. Interplanetary dust is about 5 particles per cubic cm, interstellar is estimated to be much less, but still there, so that is a valid source of continuous damage.

Answer 15

A simple handwave explanation could be that it's very hard to find a ship in deep space, but much easier to find one that's orbiting around a planet or close to a sun so the ships that are found most often are effected by whatever is in that solar system.

For example, a ship in orbit around a planet might be impacted by micrometeorites pulled in by the planet's gravity, or a ship in orbit close to a sun might be affected by radiation or gravitational shifts which slowly breaks down the structure of the ship causing metal fatigue.

In real life UV radiation from the sun, as well as constant heat\cold cycles from going into Earth's shadow break down system on the ISS. So this is a perfectly plausible explanation grounded in real world science.

Presumably the crew headed that solar system because they thought that they had a better chance of survival if they abandoned ship onto one of the nearby planets, or because the system was somewhere that potential rescuers could find.

Answer 16

There are ships and there are Ships

Even in your golden age there were haves and there were have mores.

Yes, there were ships with electronics which would fail in a few centuries, and would require continued attention from technicians to keep functioning. But there were also ships with precision and durable systems built to last for millennia.

Yes, there were ships whose fuel could break down and become useless in time. But there were also ships with perfect sealed reactors which seem able to supply energy like magic, forever.

Salvaging in a battlefield, you might find endless numbers of mass-produced fighters in various states. But how often will you find the fleet admiral's personal space-yacht, perfectly intact and waiting? How often will you find the experimental, fully automated AI-run cruiser which isn't a derelict at all, but would welcome the company of a few passengers after all these years?

All of the ships of the golden age are wonders now, but only a few were ageless marvels, and how many of those are intact and yet lost?

Answer 17

The Ancient Alloys that were the primary construction materials of the majority of ancient ships are no longer well-understood.

Back in the day, the ancients had access to some wonderous materials. They were cheap, easy to produce, and extremely durable... unfortunately, we either lost the knowledge of how to make them, or else the catalysts that made them so cheap or even possible are no longer available. Now, when ancient tech is discovered, it's anyone's guess as to whether the ancient alloy parts inside are still viable and, when they're not viable, there's no modern alternative to easily swap out. The tolerances on that wonder-alloy were incredible and, like all good engineers, the engineers of the past designed exactly to specification. To use modern materials, you'll have to do some re-engineering, and you might have to give up some features. After all, to replace the alloy firing pin with steel, you'll need to scrape out the targeting components to make room for the larger steel pin.

Some smaller items--like those that weren't high-end or those that were crafted with traditional or cultural methods--were made more classically. Things like small arms, coffee makers, fancy chairs, etc, are all possibly cultural in origin and might not suffer this flaw. This has an added bonus effect that people might pay attention to the various cultural influences of your galaxy, since it would be well-known that Traditional Kree'lin Boltcasters are the most reliable hand-held weapons tech from the past that weren't based on the ancient alloys. Find one of those babies and it'll just need a spit-and-polish to fire straight.