How long could you keep a space ship hidden but working?

[Crossroads Inc.]

It is a bit of cliche in Science fiction that some group of explorers seek an Ancient spaceship left behind by an ancient civilization. Depending on the story the ship may be hundreds or even thousands of years old. My thought, even if left in the vacuum of space, is their any conceivable way for a starship to survive and remain relatively operational within 100, 500, 1000, and then 5000years?

Obviously depending on the tech level of said civilization might determine how long a ship lasts. I will leave the type of ship relatively open for discussion.

[Solauren]

Putting it in a safe environment, like a sealed geographically stable cavern, or in orbit, would be best.

Maintenance robots would be a good idea.

[General Zod]

It is a bit of cliche in Science fiction that some group of explorers seek an Ancient spaceship left behind by an ancient civilization. Depending on the story the ship may be hundreds or even thousands of years old. My thought, even if left in the vacuum of space, is their any conceivable way for a starship to survive and remain relatively operational within 100, 500, 1000, and then 5000years?

Obviously depending on the tech level of said civilization might determine how long a ship lasts. I will leave the type of ship relatively open for discussion.

Depending on the tech level, yes. Whether or not the explorers would be able to do much more than scratch their heads at what buttons are supposed to do which function, who knows.

[Darth Nostril]

Does the ship have operational power all that time? Is it somehow shielded?
After centuries of exposure to solar winds, cosmic rays, particle impacts and vacuum ablation there isn't going to be much left of it.

[Junghalli]

The hard vacuum of space is a wonderful environment for preserving things. The footprints of the Apollo astronauts on the moon may last as long as 10 million years (reference). Micrometeorites and other sources of erosion in space are really slow compared to what we're used to on Earth. If some indentations in dirt can potentially last millions of years, you can imagine how long a solidly built structure like a spacecraft might last. Billions of years is easily concievable. So assuming the ship is in space this is one of those tropes that actually makes good real-world sense.

As for how useful or decayed the ship will be, a lot of that depends on how well its components react to the environment of space. Anything that doesn't react well to hard vacuum and temperature extremes will be trashed, but anything that can survive it will last a long time, especially if it's on the inside of the ship and protected from micrometeorites, cosmic rays, rapid temperature changes etc.

[Darth Nostril]

(reference)

Do you have anything more concrete than "MOON TRIVIA - A collection of miscellaneous observations and factoids!!!" ?

The footprints left by the Apollo astronauts will not erode since there is no wind or water on the Moon. The footprints should last at least 10 million years.

There may not be wind or water due to the volatiles outgassing from the surface many millions of years ago but there is still thermal and gravitational stress on the moons surface alone.

For a derelict spaceship to last for any considerable length of time would involve forced outgassing from all the materials used in its construction before construction could even begin, not just on the exterior, a single micrometeorite impact could breach the outer hull exposing the interior to vacuum and unless that is constructed of vacuum formed materials all that would be left is a hollow shell.

The vacuum of space is not a benign environment, even with the entire ship built from vacuum exposed materials there's still the matter of particle impacts, I'm not talking big chunks of rock merely grain of sand (or smaller) sized particles eroding the exterior hull, plus exposure to radiation.
True things erode faster on a planetary surface, but the magnetosphere and atmosphere of earth protect the surface from most of the radiation the sun kicks out, in the depths of space there is no such protection for a derelict ancient ship.

Unless you're talking about Clarketech 'Eternity Circuits' your "billions of years" is just pure fantasy, flying in the face of entropy.

[JGregory32]

It all depends on the state of the ship when it was abandoned. If the creators/crew knew the ship was going to be abandoned then they probably removed the power core, fluids, computer core, atmosphere, and any other substance that wouldn't do well when exposed to vacuum. Then they probably opened all the air locks to vent any remaining atmosphere and then towed the thing into deep space between starsystems where the chances of stuff bothering it would be minimal.

If they had to abandon the ship in a hurry or because of battle damage then the fate of the ship would be far different. The power core might have gone critical or simply shut down with reactents still in the core, the ships computer might have been damaged when the power finally gave out.

Bottom line, if the ship had been setup to be stored in hard vacuum for a while it might still be in decent shape, if not then the thing would be a junkheap.

[Darth Nostril]

It all depends on the state of the ship when it was abandoned. If the creators/crew knew the ship was going to be abandoned then they probably removed the power core, fluids, computer core, atmosphere, and any other substance that wouldn't do well when exposed to vacuum. Then they probably opened all the air locks to vent any remaining atmosphere and then towed the thing into deep space between starsystems where the chances of stuff bothering it would be minimal.

Still depends on whether the interior of the ship was engineered to withstand vacuum, if not then opening the airlocks means the interior degrades faster than the hull leaving an empty shell after a millenia or so.

Also ... if the ship could no longer fly and the crew was forced to abandon it .... after stripping it of all strategically/tactically important technology why the hell would they tow it into interstellar dark instead of destroying it or having it towed to the nearest base to prevent it from falling into enemy hands?

[GrandMasterTerwynn]

It is a bit of cliche in Science fiction that some group of explorers seek an Ancient spaceship left behind by an ancient civilization. Depending on the story the ship may be hundreds or even thousands of years old. My thought, even if left in the vacuum of space, is their any conceivable way for a starship to survive and remain relatively operational within 100, 500, 1000, and then 5000years?

Obviously depending on the tech level of said civilization might determine how long a ship lasts. I will leave the type of ship relatively open for discussion.

Well, if said starship's sensitive inner bits are reasonably well-shielded from cosmic rays and other forms of hard radiation which zip through hard vacuum with the greatest of ease, and the ship itself is shielded from drastic swings in temperature and happens to be completely depressurized, then the ship ought to be reviveable for as long as the computer memories can retain data, and the electronics can be reliably coerced into starting up. The latter might be a problem if the ship's wiring and electronics weren't meant to withstand prolonged exposure to vacuum, as the volatiles in the organic materials will all eventually outgas.

So, let's say a starship was buried in an asteroid orbiting in the outer depths of the solar system by its crew for whatever reason, and for whatever other reason, they never get around to reclaiming it. A few meters of regolith will insulate the ship from everything short of whatever radioactivity is present in the rocks and the materials comprising the ship. So long as this asteroid is far enough out, the ship will experience a temperature range from 'really frigid' to 'really, really frigid,' minimizing thermal damage (though just the act of the innards of the ship cooling down to ambient may damage components not meant to be chilled down that far, or chilled down in an uncontrolled manner.)

With that all being said, a few centuries is not out of the question. Provided our future intrepid explorers take great care in warming the inside bits up, and thoroughly examine all the electronics, the computer memories should be intact enough for the relevant systems to be successfully restarted. A few thousand years, though, and you're starting to gamble on the integrity of the ship's data storage. Not to mention even fairly small temperature swings over the course of hundreds or thousands of years may break parts that have become embrittled. Get around the aged component hurdles, and you might find that all the ship's computers will have to be reloaded from whatever passes for long-term backup discs, as the only computer memories still intact are simple ROMs. And, of course, the longer the ship sits, the worse it becomes. Even buried in regolith, the ship's innards will still suffer the occasional ionizing radiation event due to extremely high-energy cosmic rays, stars going supernova, the local star throwing tantrums, etc, etc, etc.

A ship abandoned willy-nilly, of course, will not have the benefit of protective dirt, nor the benefit of a deep orbit, nor the benefit of conservation efforts on the part of the original crew. One of these will probably be useful for little more than scrap in a scant few decades, centuries at the outside.

[Junghalli]

Do you have anything more concrete than "MOON TRIVIA - A collection of miscellaneous observations and factoids!!!" ?

How about this?

The astronaut footprints and the equipment left at the Apollo landing sites will last for several million years (until, of course, they are disturbed by future visitors)

And, no offense, but all you've given me to argue against the 10 million year figure is your own totally unsupported and unquantified statements about how micrometeorites, thermal stress, and radiation erodes stuff. If you want to dispute the 10 million year figure, I don't think I'm entirely unjustified in asking for you to give me some sort of evidence that it's wrong besides "it's from Moon Trivia!".

There may not be wind or water due to the volatiles outgassing from the surface many millions of years ago but there is still thermal and gravitational stress on the moons surface alone.

Gravitational stress is going to be pretty tiny on something floating in empty space. Thermal stress is going to a factor, assuming your derelict is close to a sun so it's getting alternately heated and frozen. How big of a factor depends on what it's made of. If it's floating in interstellar space, of course, it's in a giant deep freeze and there'll be no thermal damage at all besides whatever was caused by the initial freezing. Interstellar space or the outer reaches of a solar system should preserve a derelict very, very well.

For a derelict spaceship to last for any considerable length of time would involve forced outgassing from all the materials used in its construction before construction could even begin, not just on the exterior, a single micrometeorite impact could breach the outer hull exposing the interior to vacuum and unless that is constructed of vacuum formed materials all that would be left is a hollow shell.

I distinctly mentioned that how well stuff was preserved depended on how well it survived exposure to hard vacuum, and anything that required different environmental conditions for preservation would be quickly trashed.

The vacuum of space is not a benign environment, even with the entire ship built from vacuum exposed materials there's still the matter of particle impacts, I'm not talking big chunks of rock merely grain of sand (or smaller) sized particles eroding the exterior hull, plus exposure to radiation. True things erode faster on a planetary surface, but the magnetosphere and atmosphere of earth protect the surface from most of the radiation the sun kicks out, in the depths of space there is no such protection for a derelict ancient ship.

Unless you're talking about Clarketech 'Eternity Circuits' your "billions of years" is just pure fantasy, flying in the face of entropy.

If something as fragile as footprints can last millions of years I don't see why it's inconcievable that the basic structure, at least, could last billions. Whether or not the ship is functional, well, yeah, billions of years is going to be quite a stretch unless you have some serious Ragnarok proofing. Crossroads isn't talking about billions of years though, he's talking about thousands. If you're in the outer reaches of a solar system or in interstellar space there's not a whole lot around to erode a ship; the biggest erosive factor in space is probably going to be thermal stress, and that's not a factor if you're not near a sun (except for whatever damage is done by the initial freezing). If you are near a sun of course I'm going to go with GMT: thermal stress will probably turn everything into junk pretty quickly.

[Count Chocula]

As Solauren and GMTerwyn suggested, shielding the ship from an intersolar or interstellar environment is probably the most feasible scenario. Going by current technology, we have to deal with polymers outgassing and degrading over even our short time frame, and metals becoming brittle i.e. weaker from exposure to gamma radiation, which is abundant outside planetary Van Allen belts. Assuming materials science progresses for the next century as it has, from a layman's perspective, it seems reasonable that a spacecraft could be at least partially functional after 100-200 years idle.

IMO, uncovering a spacecraft that's been floating in space for 5,000 years, unless it's using Clarkeian "magic," would probably be a matter of looking for a reflective cloud of metallic particles and putting together the pieces. A fine plot device, in other words, but not something we could achieve with currently understood science technology (edit).

[Junghalli]

Oh, Darth Nostril, I've been looking around for a better source for the estimate on how long the astronauts' footprints on the moon would last. I found this.

The surface of the Moon now changes so slowly that the footprints left by the Apollo astronauts will remain clear and sharp for millions of years.

It looks like a legitimate site to me. It doesn't say how many millions of years it'll take the footprints to erode, but even if it's just a couple of million it gives you a pretty good idea of how ridiculously long stuff can last in space.

On that note, if footprints can survive millions of years I really doubt a 5000 year old ship would be in pieces, unless it had a very unlucky encounter with a large boulder.

[Count Chocula]

^ This may be an apples-oranges comparison. The Moon astronaut footprints are impressed in, essentially, aluminum and titanium-rich basalt dust. Inert, pliable material. A ship would presumably be made of some kind of treated metallic alloy, with whatever mix of hardness and tensile strength is required to withstand acceleration from thrusters (assuming Newtonian reactions, which I admit is not a given). If nuclear reactor containment vessels are any measure, alloys known to us become brittle over time with exposure to gamma radiation, and hence may not meet original specifications.

Understand that I'm speculating, since I'm neither a nuclear nor mechanical engineer.

[GrandMasterTerwynn]

IMO, uncovering a spacecraft that's been floating in space for 5,000 years, unless it's using Clarkeian "magic," would probably be a matter of looking for a reflective cloud of metallic particles and putting together the pieces. A fine plot device, in other words, but not something we could achieve with currently understood science technology (edit).

The hull itself ought to hold together for at least that long. The electronic bits needed to run the ship may have become so much useless scrap, but the ship's hull and superstructure ought to be recognizable as a ship for tens and hundreds of thousands of years, barring an unfortunate chance encounter with a sufficiently large bit of space debris. Very possibly millions if reasonably well-protected.

[Sky Captain]

Nickel-iron meteorites last for billions of years and are still strong enough to survive atmospheric entry. I know it`s not perfect comparison, but still ship made of steel alloys might last very long especially if protected from micrometeorites and heating-cooling cycles perhaps even after hundreds of millions of years it would still be recognizable as a ship. First things that would break down are electronics and various parts made of or containing plastics, but ship itself might still be usable after thousands of years if damaged components can be replaced.

[Stark]

Couldn't you just hide it behind an object (planet, moon, whatever) from the perspective of the only planet with intelligent life and use some kind of auto-repair system to keep it going? Assuming power and supertech, of course. Then again, just burying it in a specially-designed structure on a geologically-dead planet would do, too, but the guts would be dead without some kind of self-repair.

[Lord of the Abyss]

Couldn't you just hide it behind an object (planet, moon, whatever) from the perspective of the only planet with intelligent life and use some kind of auto-repair system to keep it going? Assuming power and supertech, of course.

I don't think it would require "supertech"; there's nothing all that extreme about self repair. We can't do it yet, but it's well within hard science fiction.

As for power; solar power could provide energy for billions of years. If it's not able/programmed to extract matter from an external source like an asteroid it would eventually erode away, but I'd think that would take billions of years. Especially if it has any ability to dodge or shoot down incoming meteoroids.

As for it hiding, would it even need to ? If there's no life on board, isn't running on more than solar power, and hasn't used it's engines in perhaps millennia would it even stand out from a random sun warmed asteroid ? Especially if the locals have no reason to think that there's any ship there to find. I know the usual arguments against stealth in space, but they generally assume that someone is actively looking, and that the target needs life support and intends to move at some point.

[tim31]

Are we going to have an autorepair system for the autorepair system?

[Ford Prefect]

If the ship can maintain itself, then it can maintain the systems which it uses to do so - so long as it has the resources and power to do so.

[Junghalli]

As for it hiding, would it even need to ? If there's no life on board, isn't running on more than solar power, and hasn't used it's engines in perhaps millennia would it even stand out from a random sun warmed asteroid ? Especially if the locals have no reason to think that there's any ship there to find. I know the usual arguments against stealth in space, but they generally assume that someone is actively looking, and that the target needs life support and intends to move at some point.

Unless it's designed to look like a natural object it's going to be noticeably artificial to any telescope powerful enough to take a direct image of it. How far out can we detect, say, 200 meter asteroids?

Then again, just burying it in a specially-designed structure on a geologically-dead planet would do, too, but the guts would be dead without some kind of self-repair.

If it's underground in a permanently cold object like a KBO would it even need any kind of repair for a long time? The main erosive forces in space are thermal stress, micrometeorite bombardment, and radiation. Burying it inside a permanently cold object should pretty effectively protect it against all three of those things, wouldn't it?

It'd probably be the closest thing you could get to sticking it inside a stasis field without supertech.

[Alyeska]

Most asteroids that we can "see" today cannot be resolved to detail. We see them at very low resolutions and only see them through their influence on light.

Asteroid 2 Pallas

That is one of the most massive asteroids out there. Look at the pitiful resolution shots we have of it. Each pixel of that asteroid is likely a dozen kilometers. Even a 2 kilometer long ship could be misidentified as an asteroid with ease. It just has to be sufficiently distant from Earth.

[RedImperator]

A spaceship in the asteroid belt is going to reflect light very oddly, even if we can't resolve the shape. On the other hand, as long as we're not in wankship size, finding a, say, 100 meter spaceship in the main belt is the first place is going to be a matter of sheer blind luck.

I don't know why you'd hide it in the main belt, though. Your chances of getting holed by a micrometeroid go up dramatically there. Burying it inside a KBO seems like the best bet for keeping it hidden and preserved.

[Lord of the Abyss]

A spaceship in the asteroid belt is going to reflect light very oddly, even if we can't resolve the shape. On the other hand, as long as we're not in wankship size, finding a, say, 100 meter spaceship in the main belt is the first place is going to be a matter of sheer blind luck.

We'd also have to examine the data closely enough to notice that it IS reflecting light oddly. It's not at all unusual for something to be discovered, and for astronomers to go back through their records and find that it was first imaged decades ago but not recognized as anything new or important.

I don't know why you'd hide it in the main belt, though. Your chances of getting holed by a micrometeroid go up dramatically there. Burying it inside a KBO seems like the best bet for keeping it hidden and preserved.

The OP seemed to be talking both about deliberately hidden vessels and abandoned ones; in the later case, something could kill off the crew while they were in the Asteroid Belt and the ship would just automatically go into stationkeeping mode. It might even travel on its own to the Belt for raw materials to keep up its self repair functions.

There's also the scenario where the ship/station/whatever was left behind and meant to be found once the local race advanced far enough.

[Vultur]

Assuming some sort of unobtainium hull that was an arbitrarily good blocker of cosmic rays and other forms of radiation, what else would cause circuitry to degrade while it was not being used or powered?

Also, an AI might be useful for a self-repair system; on the other hand, useful strong AIs may yet prove harder to build than supermaterials. (Probably will, in fact...)

[Junghalli]

Assuming some sort of unobtainium hull that was an arbitrarily good blocker of cosmic rays and other forms of radiation, what else would cause circuitry to degrade while it was not being used or powered?

Assuming the interior of the ship is kept at a cold and constant temperature the only thing I can think of is decay of trace radioactive isotopes in the chips, and maybe the occassional slow low-temperature chemical reaction. Under those conditions I'd imagine it would take a long time for them to degrade.

Also, an AI might be useful for a self-repair system; on the other hand, useful strong AIs may yet prove harder to build than supermaterials. (Probably will, in fact...)

I don't see why you'd need anything close to human-level sapience to run a self-repair system. All it has to do is periodically perform periodic diagnostics on everything and produce a replacement for anything broken. A reasonably sophisticated clockwork automaton should manage that fine.