How well would various forms of data storage survive in the vacuum of space?

Question

In my story, some personal effects get jettisoned from a spacecraft airlock. Some time later (months to years), other characters discover one of these items drifting in space. It holds information on it, but I'm not sure what format to use. I'm sure the obvious answer is an SSD or some form of flash storage, but there are reasons in the story for the technology to be outdated.

I initially wanted to use a VHS tape, but I don't know if the tape would degrade in the cold vacuum of space and/or with direct exposure to the sun. I'm sure text on paper would get bleached, but what if it was a notebook or folder that remained closed? Would a floppy disk or CD-ROM have any issues, or are all forms of digital storage equally fine in this scenario? Is this a silly question? Thanks in advance!

Edit: To be as specific as possible, I'm looking for the most viable form(s) of data storage, in widespread public use pre-2010, that would survive approximately one year orbiting the Earth at about 200,000 km/125,000 mi.

Answer 1

Paper should survive

There is not enough debris in space to consistently do damage over a year to exposed surfaces, so I assume that books, letters and the like should retain integrity. So your discoverers would at least discern information from anything written in a book or letter, provided it was etched, regardless of ink state. Etching is caused normally while writing with a ball point pen, as the process of ink transfer involves pressure to spin the ball while the pen slides over the paper. While the paint might mot survive the exposure due to sublimation or other reasons, the etching is not undone as quickly. Any debris hits would just make holes or splats, making a bit of text lost or unreadable, yet the whole might provide enough context to restore the missing letters.

Inks have troubles, but a year is not too long for them to completely degrade

The issues might hit anything printed, as both typographical print and laser print makes bits of paint adhere to surfaces rather than get embedded in them, making bits of paint less resistant to heat/cold strain and charged particles as a general exposure. Laser paint (toner) tends to get peeled off the sheets even on Earth over several years, even if the media was protected most of the time, in space this should worsen to a possibility of blotched space appearing all over a laser-printed media. Not sure if that media would stop being legible after just a single year, but give it ten, and it'll get almost blank.

Jet printed media resists heat/cold better but it might sublimate off the exposed media into vacuum, if the components of a paint were volatile enough, however that paint would leave traces in the paper for the researchers to still be able to discern the writings after several years of exposure. So count jet prints as legible with special measures.

CDs would likely break apart, and get numerous read errors

Unless the CDFS format used in your universe allows for ECC everywhere, the data on an exposed CD-R/CD-RW might be counted as lost, however large parts of it could still be read in fragments (sectors) containing one to several dozen actual bit errors. This is due to the data layer of a CD-R/W being exposed to high-energy sunlight (UV and above) and charged particles which deteriorate the state of sensitive material used to store the data. Sunlight intensity is hard enough to penetrate plastics, and anyway data writing to a CD-R/W is done with a laser of visible light (early, DVDs IIRC have an UV laser, anyway too low energy to not get erased by exposure), so the sunlight could just write random data over what was on the CD-R/W.

CD-ROMs are made differently, the data is contained in bits of metal embedded in plastics instead of in a contiguous layer of something, so each individual bit has far greater chance of survival under the sunlight. Yet there is a debris problem, a CD-ROM hit by a piece of dust at cosmic speeds has a high chance to split in half, or produce a crack in plastics that would result in it breaking apart when spun up for reading. However, since you're speaking about personal data, CD-ROMs are out of scope, as a person is not able to produce CD-ROMs on their own. So, while a CD-ROM stored in the stuff might actually survive (with probability), its contents would not belong to a person whose stuff that originally was.

SSD and Flash would lose data quickly enough

In fact SSDs are best to not get exposed to sunlight even on Earth, with UV shielding and stuff, as data on an SSD is stored in pockets holding electric charge, and any possibility of excitation causes charge leaking, resulting in different charge level at read, thus different bit sets (hello TLC+QLC!), this damage would also make the SSD controller to fail by losing its operational data (there's a ton, not going into details). Flash NAND memory also stores charge in form of triggers' state, leaking that charge is also pretty expected from charged particles and ionizing photons.

HDD might also not survive, but the data is protected better

The 2010s HDDs used quite small magnetic domains as means to store data, and some older but still working drives even did not have extra Flash NAND onboard storage for controller data (instead it was read from tracks off the working range at drive startup), and controller ROM was usually wired. Also external hard drives are normally boxed in, offering additional protection to exposed electronics. A year in space would cause air in a HDD to leak away, but some precautions taken after the HDD is retrieved (and in case of an old enough device, its controller board replaced to increase chances of it starting up normally) could let your discoverers delve into the decently vast personal storage of downloaded memes and Temporary Internet Files.

The HDDs are built with a metallic case that actually gives the data layer excellent protection from hazards in the near space, up to and including charged particles. In case a HDD is hit by dust, a too small bit would not even dent the cover, a too big bit would blow a hole through the cover and probably several disk plates out of how many installed (say a 18-TB hard drive of current manufacture has 9 plates, an old 4-TB SAS server-grade drive had two or four depending on the manufacturer, 2.5" HDDs usually have one, and should they have a IBM-2311 or similar device for their PC among their belongings (plate wise), it might only leave a dent worth several kilobytes even not preventing the device from working normally. That is, the older is the HDD, the easier it would be to get the data off it after space exposure, provided they are able to get spare parts for it. But even an average HDD of 2010s should remain perfectly readable in a clean room with tools, with about 99% of data being intact, even after several actual debris collisions. If it was boxed, and the box isn't penetrated, there is a decent chance that it'll just start up normally after being exposed to atmosphere for a day, to fill the insides through a breather hole.

Flexible media would suffer down to unreadability

The reason is that flexible media is made of polymers which are prone to deterioration under sunlight exposure, the stronger the harder. The good thing for tapes is that they are folded over a spindle at least hundredfold, so should the tape in question be retrieved quickly enough, and be initially rewound to start, the inner (close to tape end) parts of the tape might retain integrity. Still, the tape in itself would be unusable by an ordinary person, and would require special tools to be read. The good thing is that VHS tapes are analog signal, so any bit rot involved would not destroy the data.

Flexible disks aka floppies would likely suffer the same fate as the exposed or close-to-exposed areas of tape, aka crumple up destroying data stored on them. The 3.5" floppy is actually boxed, alowing it to get exposed for longer while retaining usability (reading should anyway be done raw, but floppies have large magnetic domains compared to HDDs so a lot harder to lose data to exposure, if not for the underlying media), yet they hold too small amount of data to be usable. And the 1990s floppies were not enduring enough read/write cycles to bother with them here (80s were a LOT better, I have one 720-kb floppy that's still readable, yet nowhere to read XDDD), maybe your world suffered the same. So, count tapes as damaged and unreadable without tools, floppies damaged or destroyed, depending on whether they are hardcover or not (3.5" are hardcover, 5.25" and 8" were not).

Summary

So, your best bet of recovering information from a personal media starts with books or written paper, followed by jet printed paper, followed by an external HDD, followed by a VHS tape, followed by a hardcover floppy disk. The biggest storage would be the HDD, followed by a VHS tape (with restrictions), followed by a written notebook, followed by a hardcover floppy (a notebook can hold a lot of more useful data than a floppy), followed by sheets of printed paper. Everything else you should consider being unreadable either completely or without very special tools, with a serious exception being HDD, that one depends on technology used - it might fall into both categories, depending on what happened to it over the year in space.

Answer 2

The problem of space is not vacuum, but all the rest:

• magnetic fields: these would damage any storage medium based on magnetism, like a VHS tape
• charged particles: these would damage solid state memories, magnetic storage, film
• (dust) particles: these would damage the surfaces of anything exposed to them, so writings, carvings etc. Think of sandblasting a surface
• radiation: it would break down complex molecules, affecting inks, colors, plastic and so on
• thermal cycles: close enough to a star, anything going from dark to light would go from few K to several 100s K, resulting in mechanical damages

The overall effect depends on the conditions of the exposure, in terms of time and energy.

Answer 3

My vote would be for something that's somehow ended up being retro-futuristic: minidiscs.

(image credit Evan-Amos via Wikimedia)

The MD Data format has been about since the '90s, and in its 2004-era form it could store 1GB of data. It has definitely been widely available, and though perhaps it was never that popular in the real world (and got discontinued in ~2012), we haven't had much crewed spaceflight beyond LEO for a few decades either so I think your fictional setting can stretch to it.

Minidiscs are a magneto-optical storage medium. Amongst other things, they require local heating (generally provided via a laser) and a strong local magnetic field in order to write data to them, which means they're much more robust to ambient non-ionising radiation and magnetic fields than purely magnetic or optical re-writeable medium. They have a plastic casing around the disc that can protect against a certain amount of environmental stress such as UV and some kinds of impact.

The major threat would seem to be micrometeorite damage, and that's hard to quantify as you've not given us much information about the orbit the objects would be in. 200000km is halfway to the moon, but that's an odd place to have a spacecraft in a circular orbit. A Hohmann transfer orbit between the Earth and the Moon would likely have a periapse in low-orbit around the world the spacecraft was departing from, and that low orbit is likely to have a reasonable amount of human-made debris. Further out, impacts are likely to be much rarer.

The JWST's mirror, all the way out at Earth-Sun L2 was expected to get struck about once a month, but the mirror segments do have a total area of >22m²... more than 4500x that of a minidisc seen face on, so a free-floating disc in space might reasonably not be hit at all in a year. LEO is a much dirtier place though.

This chart was taken from Sensitivity analysis of spacecraft in micrometeoroids and orbital debris environment based on panel method, and was derived from the ORDEM2000 dataset. There are newer datasets, but the ORDEM2000 set is fairly pessimistic and makes for a good worst-case, so I'll use it here. This assumes ~1000 strikes per square metre per year of 10μm debris. Now, if your disc had a large side facing the direction of travel for its whole orbit, that's a risk of 5 hypervelocity dust impacts per year. However:

• That's a worst case scenario, and difficult to engineer... it would need to be entirely in LEO, and spinning at precisely one revolution per orbit in order to maintain the face-on orientation.
• ORDEM2000 is fairly pessimistic, and other models like SDEEM2015 predict a 10-fold lower incidence of fine dust, enough to let your disc escape unscathed.
• You probably wouldn't store minidiscs loose in your pocket.. A tough storage case for the disc will actually do a pretty good job of protecting against fine dust impacts... we're not talking about sand-grain sized things here, and objects larger than dust might not actually hit during that year in space.
• There are areas of the casing that can be struck without risk to the disc inside.
• It is possible to still read some of the disc even in the event of a certain amount of damage.
• If it were edge-on to its orbit, it might reasonably not be struck at all.

So there you have it. Whilst not necessarily as long-term or easy to read as paper, minidiscs might well work OK for your needs, and have a significant storage capacity and existing technology base to handle them.

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Also, honorable mention: M-Disc, a write-once DVD/blu-ray storage system that came out in ~2010. It is chemically and thermally very stable, and assuming it avoided too much physical damage it might well survive OK. Whilst it came out a bit late for your timescale, the technology to read it was very readily available, and your setting is already deviating from the real world so it isn't too big of a stretch.

Answer 4

Clay tablets

This quite far pre-2010, pre-2010BCE even. It seems unlikely that a modern person would be in possession of clay tablets, but perhaps they are an archeologist or Luddite. Maybe they just had some engraved periodic table tchotchke on their space station desk.

Answer 5

Digital Magnetic Tape

Before modern computers, early spacecraft use magnetic tape for all their data storage needs. Early Mars lander missions (Viking 1 and Viking 2) are good examples.

The prime examples are the two Voyager Spacecraft. They still work and have been using 8-track digital magnetic tape since 1977. Granted, they are rather far away from the sun, but it's still insane to think that somewhere in deep space a tape-based computing system is still operating and has been doing so continuously for almost half a century.

Here is an image of the tape deck in the Voyager Spacecraft and you can read more about this here, on space.se

Because of this, I think your best bet for slightly retro media would be a tape of some sort. There are lots of form-factors to choose from, and provided the tape isn't directly exposed to the sun but has some sort of case, I think even consumer-grade tape cassettes (audio, VHS) would be fine for at least a year.

Answer 6

You want a personal effect that will survive.

Various answers have addressed the vulnerability of pretty much anything in common use. However, I can think of one item in modern use that I would expect the information to be retrievable from: a diary. Pen on paper in a notebook with a closure. It's closed so virtually all the abuse will be taken by the cover and the edges of the paper (and people usually don't write to the very edge), the actual written area is decently protected. It doesn't matter if the ink came off, a pen will etch the paper anyway.

Answer 7

Astronauts were constantly being hit by micro-meteoroids on their moon trip which was just a few days each way. They're smaller than a grain of sand, but travel at an average of 22,500mph and would be constantly impacting.

So unshielded I doubt any conventional data storage will be much good after a year.