Indeed.

Firstly, most people think a total severance is practically impossible. There would have to be no radio communication link, nor wire or optical fiber link, nor sneakernet or avian carrier link. It's hard to imagine a disaster that would disable every last link.

If the network does get severed for a few days, then later rejoined, one of the block chains will be accepted by the majority and the other block chain will be rejected. The transactions on the rejected block chain are temporarily lost, but will normally be re-broadcast and eventually incorporated into the accepted block chain.

Any coins generated on the rejected block chain during the separation will be lost forever, even if they have been spent to someone else in the meantime.

I saw on TV that at one point, the only way they could tweet was to call a phone number and leave a message on an answering machine, the messages were then automaticly posted on Tweeter as audio clips.

bitcoin maybe the least desirable option in another planetary system, here is why:

To create bitcoin or block chain, you need two things: hardware and software.

#1. Assume you didn't bring everything with you, to create hardware (CPU in particular), you'll need to have Silicon, Boron, Phosphorous, Aluminium, Copper, Gold.... not mentioning those multi-billion dollar fabs.
http://www.tomshardware.com/picturestory/514-intel-cpu-processor-core-i7.html
"A microprocessor is the most complex manufactured product on earth. In fact, it takes hundreds of steps and only the most important ones have been visualized in this picture story"

#2. To write and maintain the bitcoin software, you'll need to have a group of programmers and make them happy (providing food,shelter,drugs, sex,games,whatever), which can be more difficult than #1.

gold, silver, or seashells will be much better choice.

There's going to be scenarios where connecting to the Internet will be difficult if not impossible. If in fact Bitcoin must be connected to the Bitcoin network to function properly I was thinking as a solution that there could be multiple Bitcoin networks running. The main Bitcoin network that we use, and a Bitcoin network running in an intranet for submarines where Internet is not always available but currency is always needed. Then to link the two networks together the same people who are trading cash for Bitcoins could also trade Bitcoins for Bitcoins on both ends of the Network. I.E., something like this [Main Bitcoin Network (Bitcoin Trader<-)]---[(->Bitcoin Trader) Submarine Bitcoin Network]

I think it would be really interesting if someone setup a Bitcoin experimentation networks to test ideas like the lost in space idea in this topic. That way we can truly see what would happen if a total netsplit were to occur and people were still performing Bitcoin transactions.

space = insulator. ever wonder why thermos are called vacuum flasks?

But, that's all you can do in space. Conduction and convection are out. And just as a surface can radiate heat, it can also absorb radiation, from the Sun for example. I think that cooling equipment in space presents some interesting engineering challenges.

I wonder how the ISS does it. Maybe it has radiators shadowed by the solar panels. I bet it can also make use of a fair amount of convection, since it orbits in the upper atmosphere.

Do they got actual internet on the ISS or do they use only specialized communication means (plus regular radio) ?