The next Apollo 13 will probably be a software problem , doesn't hurt if they can read up about it

You're proposing that if something goes wrong on the ISS, the crew will need wikipedia to solve it? Not... talking to Houston or just taking the Soyuz back?

I wrote a crap SDR basically just from wikipedia, maybe their radio broke.

Presumably you have seen a science fiction film before, use your imagination.

> The next Apollo 13 will probably be a software problem , doesn't hurt if they can read up about it

What good would an "offline backup of Wikipedia" do in that situation?

Wikipedia is good for one thing, and one thing only: getting some cursory knowledge on a topic you're unfamiliar with. It's the tourist map to the "sum of all human knowledge." If you expect to use it for anything else, you're asking too much of it.

I have found a lot of the math articles to be quite good.

So, stackoverflow, not wikipedia, then?

So its contents aren't lost if Earth's surface gets depopulated.

Putting it on ISS wouldn't help with that, although I'm sure this comes as no surprise to you, given that its orbit is a decaying one.

I like the idea of periodic Wikipedia moonshots, although the storage format is kind of an open question, I've wondered for awhile if a DVD made from e.g. quartz, platinum, and titanium might be up to the job.

A full backup would fit on 12 double-layer, single-sided disks; I'm being conservative and not using Blu-Ray numbers, since density and longevity are always somewhat in tension. Probably more expensive to put them safely on the moon than to manufacture in the first place.

Agreed. I think even bare nickel or iron would probably be fine. Holographic glass laser damage can in theory handle higher recording densities and, like your DVD, isn't vulnerable to surface damage.

In space you probably don't have to worry as much about minor surface scratches and oxidation, though. You just have to worry about outgassing and meteoroid impacts. Some of them you can stop, and some you can't. On the bright side, they're very rare.

I think common media formats like DVDs are designed with a lot of emphasis on speed, both of reading and of duplication. This compromises both density and longevity. If you, instead, allow yourself the luxury of FIB milling to write and an electron microscope to read, you can manufacture in any vacuum-stable material at all, and you can engrave your archival message with, say, 50-nanometer resolution. At one bit per 50 nanometers square, you get five gigabytes per square centimeter.

I think that with e-beam photoresist cross-linking followed by etching you get about 500 kilobits per second, and I think FIB milling is a little slower, so it might take a few weeks to make the copy — obviously unacceptable for a consumer CD burner but fine for periodic Wikipedia moonshots.

Relevant material about CD-R and DVD-R archival: https://news.ycombinator.com/item?id=33117813

And what's the point of it in space? Knowledge doesn't disappear when it's not on wikipedia. If humans are still around they will continue contributing to knowledge. Just because it's not printed or recorded doesn't mean that information or knowledge doesn't exist.

> if Earth's surface gets depopulated

There are 14 people on the ISS. If they were the only ones left, they would certainly not have the breadth knowledge of a Wikipedia dump.

And how would these 14 survive if they are the only ones left? Do you know that there's a whole support team to support them in space? It's not just 14 people. There are hundreds on the ground supporting them.

Yeah, ISS itself is not that realistic.