As I squeeze our solar system into the Traveller rules for my setting book Orbital, I find myself requiring some variation for the travellers.

I've made these very minor re-interpretations to the UWP codes to provide a bit more variation in the trade codes:

Atmosphere: Mars has a Very Thin, Tainted atmosphere due to half a century of terraforming, this increase in pressure has allowed a small increase in average global temperature (and enables me to describe Mars as a 'desert world'. Some worlds are listed with trace atmospheres in the scientific literature, a tenuous body of gas which has measurable chemical constituents (including Io and Triton). They are listed here as Atmosphere 1 (Trace) although the actual pressure readings of these atmospheres are far lower than those given on TMB p.171.

Hydrographics: To provide more diversity in trade codes, many of the icy moons have been given Hydrographic ratings of 1 qualifying them as Ice-Capped. Since nearly every body in the solar system that has regions experiencing little sunlight has deposits of water ice, we use the term Ice-Capped to mean ‘has liquid water beneath an icy crust’. These liquid water oceans are postulated on Europa, Enceladus and on other moons also. Ice-capped means ‘a subsurface ocean beneath the ice’.

How does this sit with you? I really need some designation for a subsurface ocean,and calling anything with ice ice-capped really won't work because almost anything beyond the Main Belt is going to be Ice-Capped.

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Paul Elliott
ORBITAL: The Solar System Setting for Traveller, a hard setting full of TL 9 technology, rockets, landers, Orion capsules and colonies on Mercury, Mars and the moons of Jupiter and Saturn.

http://zozer.weebly.com/orbital.html

I would agree that Mars should get a thin atmosphere, though I'm not sure it would also need to be considered 'tainted'. Being so thin you would need (probably) the same gear that a tainted one would (or perhaps more, since its so thin, and you could have a standard earth's atmosphere that was tainted and you just needed a filter).

As for the codes, well, you are in a bit of a quandry there. I think the easiest way to dodge that would be for 'ice capped' to be a more encompassing description, that allowed for multiple variants of ice being there. I don't think the codes have anything in there for an ice 'planet'. I guess they just assumed moons (like mimas) would not get a full UWP.

I don't know how to account for a sub-surface ocean. But for the most part, would it even matter? It would only be of consequence if the players had landed, and if it was part of the adventure it could simply be written into the description of the world.

The UWP have many short comings. I was wondering the same thing. Just get as close as possible but note any irregularities or differences. Perhaps a small portion before the world listings to tell the reader how Orbital UWPs differ from standard Traveller UWPs. Then elaborate on specifics within the separate world descriptions. So basically, I agree with phavoc on this.

Let me know what you come up with.

Ben

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Give me a Kennedy class fast missile cruiser and I'll give you an irradiated hulk that used to be a Kafer warship. -- Captain M. Reynolds Fletcher USAF

I would suggest extending some of the classifications with subcategories for campaigns that need that level of granularity. So a world's hydrographic rating could be extended with an optional flag that specifies the composition of the liquid found on the surface (e.g. liquid hydrocarbons rather than water). It could also be extended with an flag that specifies that the liquid is in the form of a subsurface ocean as on Europa. Optional flags of this nature could function in the same way as the existing Trade classifications and appended to the canonical UWP as a set of 'secondary characteristics'. The beauty of this approach is that it preserves the elegance of the existing world generation system while making it possible for GMs who want more detail to 'drill down' into a secondary layer of information. THis would also allow GM's to generate a high-level overview of a world using the normal syastem and then develop secondary details as required.

One of the things I did is change the definition of Very Thin and Very Thin Taint (ATM 2 and 3). In the CRB description, they are listed as having oxygen. I remove that part. Only ATM 4-9 has oxygen.

Then
ATM 2 become Very Thin Corrosive
ATM 3 becomes Very Thin Exotic

For the frozen moons - which GDW didn't know about in 1977, I have created additional UWP codes for Frozen water surfaces. I use the Hydrographic spot in the UWP, but I use codes B thru L (not I) to represent 10% to 100% Frozen Water surfaces. These UWP codes are only used when a world is located Outside the habitable zone (Temperature must be Frozen).

I have also created UWP codes for larger worlds (like those new Super-Earths) that extend the Size code above A. I have tables that create Non-Mainworld planets that go way beyond the simple 2D-2 or 2D-7 rolls that are used for the mainworlds.

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My friends call me Richard.
You can call me Sir.

I used the Very Thin/tainted code for Mars due to it being carbon dioxide.., climbing out onto the wing of an airliner would just be Very Thin! I agree though, you'd need the same equipment to survive both... an oxygen mask and tank.

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Paul Elliott
ORBITAL: The Solar System Setting for Traveller, a hard setting full of TL 9 technology, rockets, landers, Orion capsules and colonies on Mercury, Mars and the moons of Jupiter and Saturn.

http://zozer.weebly.com/orbital.html

If you are serious about having worlds inside and outside the habitable zone, then some additional atmospheric codes probably need to be added to the UWP.

Remember the UWP was designed for the major world in each system, often in the habitable zone.

For outside of the mainworld, I would expand the Size, Atmosphere and Hydrographics listing to allow for super-Earths, Panthalassic worlds etc.

I would allow Size B and Size C worlds (and possibly Size D).

Atmospheres should include Very Thin Exotic, Thin Exotic, Thin Corrosive, Standard Exotic, Standard Corrosive, Standard Insidious, Dense Exotic, Dense Corrosive, Dense Insidious, Very Dense Exotic, Very Dense Corrosive and Very Dense Insidious.

I would expand the Hydrographics using the letters as I described above, to cover the percentage of the world covered in Ice.

I would also expand the Very Hot and Very Cold temperature ranges. I would consider the freezing point of CO2 as an important temperature as well as the freezing point of Oxygen and Nitrogen. On the Very Hot side, the melting point of Lead and the Melting point of Rock becomes very important as well.

Tables to create all these new variations would get pretty big and be much harder than the simple 2D-7+(something) that is used for the Main World.

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My friends call me Richard.
You can call me Sir.