A spacefaring people buries their fallen heroes in space. The bodies are adorned in uniforms (fabric), equipped with the weapons they carried in life (mostly aluminium, steel or polymer, but containing no battery, chemical explosive, flammable or corrosive), and sealed in tough polymer coffins, which are airtight and filled with inert gas. They are then irradiated to kill any bacteria.

The coffins are deposited upon a lifeless moon, or in one of the Lagrangian points around the planet where the hero fell.

How well would the coffin's contents survive the test of time? How far into the future would it remain intact, and how well?

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    $\begingroup$ Why would they be filled with inert gas? Would be easier to just have it be unfilled because then you wouldn't need a pressurized container. An unpressurized container would also make the thing survive longer because there won't be gas that us constantly changing pressure inside due to temperature deltas. Without gas, it would be expected that the whole thing will survive indefinitely unless someone/something external comes to tamper with it. The lifespan would most likely be a function of the likelihood of being hit with space junk. $\endgroup$ Dec 15, 2017 at 18:09
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    $\begingroup$ @A.C.A.C. There is still photodegredation of the polymers in the box to be concerned with. $\endgroup$
    – sphennings
    Dec 15, 2017 at 18:20

3 Answers 3


The coffin could survive almost indefinitely in human terms depending on where it was located.

If it was in the shade on an airless moon then temperatures would be very low and temperature cycling would be minimal. Freezing would disrupt all of the cells in the body, but being frozen, it would remain intact almost indefinitely (millions of years).

If the coffin was left in sun light then regular temperature cycling would repeatedly freeze and thaw the body. As all the cells would be disrupted by freezing the contents would leak out and the soft tissues would slowly disintegrate over time leaving the bones and artefacts laying in a body tissue mush (perhaps over tens of years but very much depending on the degree of heating).

At the Lagrangian points the coffin would be in perpetual sunlight and if sufficiently close to the sun might warm, heat or roast the corpse depending on location. Unless the coffin was sufficiently robust it might explode due to steam pressure. Although protected from biological decomposition, under elevated temperatures chemical degradation would occur and the soft tissues would eventually end up as a degraded mush (perhaps over tens of years but very much depending on the degree of heating).


Pretty much forever.

Most decomposition of (human) bodies is done by organisms in the environment in which the body dies. It can also be slowed or eliminated by storing the body in a dry and cold environment, which space certainly fits the description of.

One prime example of an extremely well-preserved body is the body of civil rights leader Medgar Evers who was assassinated in 1963. When his body was exhumed for a civil rights investigation in the 90's, they found that the body was almost perfectly preserved, which helped finally get a conviction against his assassins. This is likely attributed to the fact his coffin was lined with lead, which prevented bacteria and decomposing organisms from getting in. Obviously storing a body in space is even better, considering the lack of decomposers present in a vacuum.

Another natural phenomenon that results in well-preserved bodies is bog bodies. Due to the acidic water, lack of oxygen and low temperature preventing decomposition. Some bodies dating back as early as 8000 BCE have been found mummified in bogs. The 4th Century Tollund Man found in 1950 was originally thought to be a recent murder victim due to how well they were preserved.

I'm not sure how irradiating the body would affect its decomposition though. Although it would certainly kill bacteria, I would think it could also damage the body. You might be better off just cleaning the body before burial and sterilizing its uniform and coffin separately.

I would also store the body in near vacuum as well as opposed to filling it with an inert gas as I would think your main problem would be it being hit by space junk. Keeping it in near vacuum would mean that if the coffin is punctured, you won't have explosive decompression that could damage the body. It would also minimize pressure fluctuations from temperature changes. Obviously, you would want to lower the pressure gradually instead of all at once in order to prevent damage to the body. Storage in a vacuum would also help insulate the body, as radiation through a vacuum is an extremely slow way of transferring heat.

You may also want to insulate the coffin with a vacuum layer between an inner and outer shell. If you leave a coffin in orbit around a planet, you should be able to calculate roughly how large this layer would have to be to prevent the body from heating by calculating how long it would be in direct sunlight vs how long it would be on the dark side of the planet. Alternatively, you could place it far away from a star.

Your main problem is probably going to be space junk and other unpredictable cosmic events such as solar flares and gamma-ray bursts.

  • $\begingroup$ @Gryphon thanks for the corrections! Auto-correct doesn't work very well on my phone! $\endgroup$
    – Rob Rose
    Dec 15, 2017 at 20:57
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    $\begingroup$ Another example was the body of Mallory taken down from near the summit of Everest... Perfectly preserved! $\endgroup$
    – RemarkLima
    Dec 16, 2017 at 1:53
  • $\begingroup$ @Stephan Thanks! I actually don't think the math would be that hard. I'm sure someone on the Physics or Space Stack Exchange could do it! $\endgroup$
    – Rob Rose
    Dec 17, 2017 at 1:44


Or at least until the coffin is hit by space debris and punctured (though frankly I'm not sure that would change a lot, space is called that for a reason, it's basically empty vacuum).

As A. C. A. C. mentioned in the comments your probably better off not putting any gas in at all, vacuum packing it to all intents and purposes. In which case you have used three methods normally used for (food) preservation; canning, vacuum packing and irradiating.

Either one of those three methods could give your corpse a pretty long 'shelf' life, all three combined I would guess it could reasonably be presumed to last a very very long time without much in the way of deterioration (which I assume is what you mean by 'survive').

  • $\begingroup$ Note that you don't want it TOO irradiated. Otherwise, the corpse will start to burn up. You can get around this by adjusting the radiation shielding of the container, so that it lets through the optimal amount of radiation (given an average amount of background radiation). $\endgroup$
    – Johnny
    Dec 15, 2017 at 20:46
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    $\begingroup$ +1 for the mention of food preservation. Might make for an interesting antagonist; aliens that eat the corpses as a luxury food. $\endgroup$
    – Stephan
    Dec 16, 2017 at 1:45

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