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

[Axiomatic]

If you wanted a spaceship hidden wouldn't the best place to hide it be inside an asteroid of sufficient size? That way, you're hard to see and hard to hit by micrometeorites.

[Junghalli]

If you wanted a spaceship hidden wouldn't the best place to hide it be inside an asteroid of sufficient size? That way, you're hard to see and hard to hit by micrometeorites.

A Kuiper Belt object would probably be better. You want a stable deeply cold place, because it'll both eliminate thermal stress (except for the initial damage from the freezing), and it'll slow down or stop any destructive chemical reactions or biological decay. A KBO is also probably somewhat less likely to be investigated given its greater remoteness.

[Lord of the Abyss]

If you wanted a spaceship hidden wouldn't the best place to hide it be inside an asteroid of sufficient size? That way, you're hard to see and hard to hit by micrometeorites.

A Kuiper Belt object would probably be better. You want a stable deeply cold place, because it'll both eliminate thermal stress (except for the initial damage from the freezing), and it'll slow down or stop any destructive chemical reactions or biological decay.

On the other hand, a ship with self repair capability would last even longer, especially if you are talking about a ship that stays fully functional. I'd expect small, molecular scale random changes * to happen over time, which would damage or ruin anything built on that scale. Like advanced computer components. A ship with self repair could last indefinitely, but would either need to run a power plant or gather solar power. Running machinery and especially a power plant would produce some heat - which would stand out in such a cold environment -or in the case of solar power greatly benefit from being closer.

It does occur to me that if the ship's self repair systems and hull can handle it, and it has a fusion plant, a good place to hide it would be inside Europa. The hydrogen in the water fuels the fusion plant, the ice shell hides it, and if one postulates life in Europa's internal ocean there's even a good reason why someone would want to bore their way in and look around. Or bore out - perhaps the ship is there because it was built by a dead Europan civilization. That would also explain why it's built to take that environment - the same reason a Space Shuttle is built to function in a warm oxygen rich atmosphere.


* That happens with Antarctic extremophiles I understand; they live so slow that the complex organic molecules they are composed of randomly "flip" into new configurations. This can kill them if it happens to enough of them. A ship embedded in a KO would be much colder of course, but you can't reach absolute zero, so there will always be some movement.