Actual survival rules I'll probably shuffle into a game-mechanics chapter rather than include with the habitat description. That said, [url=http://www.orbiter-forum.com/showthread.php?t=15763]this forum post[/url] has a very good primer on the radiation exposure danger of the Gallilean moons. In particular, two hours outside on Io without sufficient shielding means the average person has a 50% chance of death inside of 30 days, and exposure for twice as long (4 hours) has a 100% death rate inside of two weeks. With the Radiation Shielding implant, you can roughly extend the exposure periods by a factor 30, so it'll take 2.5 days to reach LD50/30, and 5 days before you have a 100% death rate. Mind, most of this radiation comes in the form of charged particles, mainly electrons, and is beta-radiation rather than the more common gamma rays one usually needs to protect against. There's also significant ultraviolet radiation. Both UV and Beta radiation are fairly easy to shield against; UV radiation attenuates fast (sunscreen is rather effective...) and Beta-radiation is quickly stopped by a thin layer of metal or plastic. Whereas immense amounts of gamma rays would need terribly thick layers of protection, UV and Beta-radiation doesn't scale all that much with intensity. Though, one should keep the Bremsstrahlung in mind, which is an effect where Beta-radiation emits X-ray or gamma radiation when it hits a shield. At a guess, spacesuits would have to be shielded with metal plates. An ordinary vacsuit would definitely be too flimsy to provide any significant radiation protection. To have an adequate level of protection, I'd recommend a Hardsuit (EP p. 334), which is also able to offer excellent protection against the 110 K temperatures on Io's surface. It might possibly need to be specialized with extra layers of polyethylene and a thin aluminium layer to offer enough protection. Emergency Bubbles (EP p. 332) and Shelter Domes (p. 333) can be used for shelter, though you'll need to bury the tent under a thick layer of sulfur/sulfur-dioxide snow; at a somewhat wild guess ([url=http://people.virginia.edu/~rej/papers09/Paranicas4003.pdf]i.e. assuming that sulfur snow behaves similarly to water snow[/url]) a little under half a metre or so of snow should be enough. It'll be oddly like arctic survival, but in this case you don't need the snow to retain heat (the Bubble suffices for that) but to protect against radiation. The real problem with tenting on Io (other than the lightning strikes, volcanoes, radiation, lava flows, and earthquakes) is that you'll need to scrub yourself of all sulfur and sulfur-dioxide before you enter the Bubble's atmosphere. I imagine that people would bring along special Emergency Bubbles that can connect to other Bubbles or a Shelter Dome, but are environmental isolated. Inside these, you make a cursory scrub of the environmental seal of the hardsuit, and then connect a person-sized tube to the hardsuit and climb out through it. The tube is connected to the other Bubble or Shelter Dome. This way, you can climb straight from your hardsuit into the Bubble/Dome without bringing any toxic ice into the Bubble/Dome. A vehicle can be much better shielded though, and if large enough can also be mounted with a proper decontamination stall for hardsuits. All in all though, spending even small amounts of time on Io's surface probably increases the risk of developing cancer later in life significantly, so radiation treatments and up-to-date biomods is probably a good idea. As for electronics, they can usually be as shielded as any transhuman can, especially if internally mounted in a hardsuit or vehicle. According to [url=http://www.projectrho.com/public_html/rocket/radiation.php]Anthony Jackson[/url], as quoted on Atomic Rocket, normal electronics can barely withstand a Gray, and would fail or crash almost instantly if exposed to significant radiation - certainly no good in the 36 Gy/h environment of Io. Robust equipment might last an hour or ten; properly rad-hardened electronics could last maybe half a week to a month before it would simply stop working. As described, almost all EP electronics are shielded against electromagnetic pulses through use of fiberoptics, which might offer some protection against normal radiation; I'd probably grant all electrical equipment the rad-hardened quality and let it last a month or so before critical failure. Perhaps almost indefinitely if the equipment is as well-shielded as a person on Io would be. Miniature electronics would not fare well in any case though, so an exposed Ecto or nanoswarm would find itself fried almost instantly. Swarmanoids would probably end up inoperable, if not harmed, rather quickly. Synthmorphs and cyberbrains would be at increased risk of brain damage because the radiation would upset their storage media. This would also apply to Cortical Stacks, which will probably be wiped almost clean in a matter of hours-if-not-minutes when exposed to the full strength of Jupiter's magnetosphere. This does not speak well for people who die on Io's surface, if they're ever even found beneath the thick layer of toxic snow, and avoid being buried by a lava flow. (Hint: exposing a cortical stack to an active volcano is not a good idea.) Since miniature electronics are at high risk of disturbance from radiation, nanoaugmentations will probably not fare well unless the host body is well-shielded. At it's most basic, the nanomachines will simply fail at doing their job, because they've been damaged. Worse, though, is when the nanomachines are instead reprogrammed or mutated, causing them to do something not quite what they were intended for; you certainly don't want your Medichines to suddenly think that your white blood cells are actually a toxin and start exterminating them, or your nanophages to start eating your Medichines. Maybe your Personal Power Plant decides to all gather in your thyroid gland, giving you an even worse radiation poisoning? It would be rather ironic if your respirocytes decided they were most needed in your carotid artery, blocking off blood supply to your brain with their collective bulk... And then you get the really fun things, like radiation damage to the nanoware [i]factories[/i], causing the over-production of (defective, malignant) nanites, giving you nanomachine cancer. In short, there's a reason the Jovian Republic Io Tourism Board doesn't allow nanoware on visits to Io; they'd really prefer [i]not[/i] to have to clean up the mess that happens when someone has a sudden onset of cancerous nanoviruses develop in their bodies. And by "clean up", I mean flamethrowers and plasma grenades. It's the only way to be sure.