Spaceships: Escape to the asteroids

[wellspring]

Originally Posted by munin

Armor provides radiation protection to people who move out of the protected systems. GURPS Spaceships 5 and 8 assume that ships are designed so that important systems (habitats, control rooms, engine rooms, etc.) are protected by the mass of other systems, but that if you move to, say, a Cargo Hold your protection is determined only by the armor systems.

Originally Posted by Fred Brackin

It might be no better than full fuel tank but I wouldn't let you claim the bones for an empty fuel tank. Your fuel tanks are relatively unlikely to sit around being full all the time.

OK I stand corrected on both points. The former is a rule that I'd forgotten about. And while Fred's rule isn't strictly RAW, it's a house rule that I'd consider implementing myself. IF you decide to implement it, you'll want to think about the implications-- and your players will want to think about what fuel tanks to empty first!

For the sources of radiation, look at Transhuman Space Classic, pages 59 and 30. Combat and gas giant magnetosphere radiation isn't an issue, since you're only planning one trip to the Belt. So the two sources of radiation you'll have to worry about are cosmic rays and solar flares. Cosmic rays are cumulative every week. Solar flares are rare bursts of up to 6000 rads (divide by the square root of the distance in AU from the sun-- that's between 1/4 and 1/9 once you're in the Belt).

For cosmic rays, we're talking 1 rad per week. Shielding doesn't help nearly as much, but the good news is that as long as the crew stay within the habitable section of the ship most of the time, you don't have to worry about PF in areas like the cargo section. The same goes for solar flares, but for the opposite reason; during a flare, everyone should be retreating to the storm shelter (ie the core habitat system with the highest PF). If the crew invests in a couple utility robots, they can minimize the time spent in low-PF areas (even if there isn't good AI in your setting, they can be remotely controlled by the crew).

One last thing that just occurred to me. Since your crew can't get anti-radiation nano, what about gravity! There are VERY serious health problems associated with long-term exposure to microgravity, and your crew won't have zero-gee tolerance nanomods. Your ship could have spin gravity, but Spaceships limits that to 0.1g. Perhaps you could go for spin tethers?