GURPS Space campaign setting

[JAW]

Originally Posted by combatmedic

No reason both solutions couldn't show up in the same setting[ along with more expensive transatmospheric FTL starships]. Economic, technical, and cultural factors could allow for more than one way of doing things. Perhaps different species prefer different approaches?

Hmm - maybe memer&sarets operate the FTL liners.Where there is liners regularly going it would generally be unprofitable for other types of FTL commercial ships to go as as renting rides from the liners would usually be cheaper than operating ones own FTL drive - wich rises a question - is there anything limiting the use of FTL once one has a drive? Expensive exotic fuel, maybe... or maybe FTL astrogation is hard and somewhat hazardous and requires a skilled sentient pilot - but the memer/sarets have the knack for it so the liners almost never crash...

[MrId]

Originally Posted by combatmedic

No reason both solutions couldn't show up in the same setting[ along with more expensive transatmospheric FTL starships]. Economic, technical, and cultural factors could allow for more than one way of doing things. Perhaps different species prefer different approaches?

This will be a long, rambling, somewhat unfocused post, but I've thought about how surface to orbit would work in my setting for a while. Since the setting I'm trying to build isn't incredibly different from the one you're working on, I thought I might share. This is the first time I've typed this up, so it's kinda fuzzy, all over the place, and lacking in numbers, but I think it's a start. Anyway, this is how I addressed some of the economic, technical and cultural factors:

I basically envision three tiers of spaceports. The bottom tier is for planets with relatively low population and little capital to invest in a spaceport, i.e., a frontier. Here the spaceport is a launch/landing facility for conventional, SSTO spaceplanes. Assuming an Earthlike planet, and an unwillingness to damage the environment with nuclear rockets, I picture these craft as evolutionary descendants of the VentureStar. The are the least cost-efficient method of getting stuff from the surface into orbit, bur require the smallest capital investment. The SSTO designs can also be tailored to the requirements of particular planets -- orbital velocity being the big one. A SSTO designed to take off from Earth is going to be overkill if your shipping stuff off the surface of Mars.

The second tier is a laser launch facility, which lowers the price of launching things into orbit, but requires the huge capital investment of the launching lasers and the reactors to run the lasers. Again, the rockets themselves are SSTO and reusable, but dependent on the laser launch facility for take-off (they have a secondary engine to modify their orbit for re-entry and glide to a landing strip.) So this tier is for developed planets that see enough trade to support such a facility.

The top tier is a space elevator, which can lift loads very efficiently, but has a mind-boggling initial investment. A planet with a space elevator can ship all sorts of goods (although probably not compete with asteroids for things like ice and iron). Ultra-Tech (4E) gives estimates of shipping cost to orbit being $3/lb after the construction costs are paid off.

Obviously, there's a lot of variation within this structure: planets without Earthlike biosphere (or that don't care about environmental damage) could use nuclear rockets. If your Bwaps are retrotech, they may eschew laser launch. Some of the economic implications seem to indicate to me that a space elevator can concentrate a lot of economic power in a particular system -- it can probably make everything that a laser launch planet can, and those goods can be made for the same price, but at their destination sold for less, since shipping costs will be less. Frontier planets may not have any industry which can make manufactured goods that are worth exporting if those goods have to be lifted by the relatively inefficient SSTOs. If these planets have some kind of luxury good that doesn't need a huge manufacturing base (premium wine is the example that keeps rattling around in my head), then this could be their export. They could also trade land or resource rights for manufactured goods, which is a good set up for classic "evil oppressing mega-corporation versus plucky, independent colonists" style conflict.

All this assumes that the planets are basically Earthlike. All three options work on non-Earthlike planets that people could plausibly live on, although if there's no chance of terraforming the planet, nuclear rockets could easily replace chemically powered SSTOs. I've also assumed that there are usually orbiting trade stations (or elevator terminals) where the rockets can dock and exchange cargoes with deep space craft, which then pop into hyperspace (after getting to the jump distance) to take said cargo to it's destination.

The reason I prefer the surface-to-orbit side to be based on the planet rather than hopping around in a FTL ship is that a design optimized for a particular planet should be cheaper than a generalized one -- never mind the fact that a spaceplane for landing and taking off from an Earthlike world is basically going to convert those wings and control surfaces into deadweight when landing on an airless body (and expensive deadweight at that...) Incidentally, Far Trader describes LASH operations in Traveller where an FTL ship brings an number of non-FTL cargo ships into a system, drops them off at the 100 diameter limit, and picks up a new load of ships at the outbound leg of the jump.

I haven't worked out examples of these craft yet, nor really "run the numbers" -- this is mostly just handwaving. I've been trying to build a SSTO with the playtest files from VDS and it's hard to do (just like in VE2).

Boy, this post needs some editing.