Spaceport types


In my tables of colonies for Flat Black you will find a column of “Spaceport” codes, each of which consists of a digit and a letter. These are a legacy of ForeSight, the original native game system of Flat Black

The digits represent the amount of material, mostly freight, that is lifted from or landed on the planet, and therefore the total scale of its spaceport or spaceports. The scale is logarithmic base ten, rounded to the nearest whole number. Negative characteristics are recorded as “0”, As a result each size code covers a factor of ten in throughput, except scale 0, which covers everything from no traffic up to ₢316 million per year. The busiest spaceports in Flat Black are those of Simanta, which handle ₢300 trillion worth of freight per year, and are scale code 5. The planet with the least trade volume is Eppur, where only ₢14.7 million worth of freight is launched or landed each year. Eppur’s spaceport code would be -2N if negative scale rating were used.

The letters are type codes, as follows:

N No formal facilities
There are at best landing areas of firm rock or concrete, where you can get water to refill the propellant tanks in your lighter, fenced to exclude wildlife. Airports, for instance. At worst, you figure out somewhere safe to land that is as convenient as possible to the consignee of your cargo. The defining characteristic is that there is not lighter service operating from the colony. Cargoes cannot be delivered to orbit, and the ship that brings them has to carry a lighter with which to land cargo. That indicates a world to which a ship comes only at intervals of weeks, perhaps months. Otherwise it would be cheaper to park a cargo lighter in orbit rather than haul it around.
G Ground facilities
The planet has one or more dedicated landing facilities for cargo and passenger lighters, connected to surface and air freight networks, and having at least minimal resources to fuel, service, and repair orbital lighters. It also has some sort of surface-to-orbit service involving lighters that are kept in the system permanently. Cargoes can be delivered to orbit; ships serving the colony do not have to carry cargo lighters with them.
O Orbital facilities
There is at least one orbital spaceport, which has facilities for refuelling starships and at least minor repairs and service. Cargoes and complements of passengers are assembled in the orbital facility for quick loading and embarkation. Ships can be unloaded here expeditiously, the passengers and cargo waiting in the orbital facility for a lighter service to the ground.

Where there are orbital facilities there are invariable multiple, regional ground facilities and landing areas on the planet, connected by cargo and passenger lighters to the orbital facilities.

T “Tower” facilities
The code “T” denotes some sort of infrastructure for non-rocket space-launch. Actual tower facilities (beanstalks, orbital elevators) are unusual, because they are slow for passengers and cause inconvenience in the use of lower orbits. Aeneas and Todos Santos built towers (cheaply because of their short days) and are now considering demolishing them. Rotating skyhooks, termed “rotovators”, are more common at small planets, launch loops at large ones ones.

The orbital elevators at Aeneas and Todos Santos have spaceports in the tower facility at geostationary altitude. Other “T” infrastructure involves the payload being carried in orbital vehicles to rendezvous with an orbital spaceport or directly with a ship. T facilities provide cheap access to orbit for freight, but slow and inconvenience transfers from ground to spaceships for passengers. They therefore displace cargo lighter services but not passenger lighters.

Whatever spaceport facilities a planet has, there is always a landing field or ground facility in or adjacent to the Imperial extraterritorial enclave in each colony, secured and operated by the Empire. Only where trade volumes are low does this serve as the main commercial ground port of the colony.

The Empire built and operates the orbital ports of many colonies with modest development levels, and colonies with T and high O spaceport ratings often have one or more Imperial orbital facilities among their several orbital ports. In no case was the “T” infrastructure at any colony built by the Empire, nor does the Empire run any of those facilities.


My feeling is that ships capable of landing their own goods (whether it’s the FTL ship that’s streamlined, or LASH) are basically uneconomic compared with deep-space-only vessels on the same routes that can use local infrastructure. So prices of transport to and from N-class worlds are likely to be vastly higher than elsewhere. (The Imperial monopoly may alter this.) The eternal question of interstellar economics is “what is worth carrying”, and I suspect that things which on most worlds are imported cheaply will simply not be findable on an N-class world.

I looked into this in some detail when I ran Tempt Not the Stars, with the brief of having a Traveller-type free trading game without the massive weight of Traveller’s backstory. That’s probably the last setting I’ll ever write with reactionless thrusters in it; I know more about the implications now. But that produced the special case of the magnetic spaceport, for worlds which had substantial gravity but thin or no atmosphere: it’s essentially a spacecraft-sized gauss accelerator to catch inbound ships which don’t have enough acceleration to do the standard reactionless drive thing of hovering to a landing.

In Wives and Sweethearts, the main world of a system is always* at least an O, because orbital stations are cheap to build and run (especially when you rent out space for zero-G manufacturing). Worlds that have been settled for a while are usually T unless there’s some reason not to construct a beanstalk or equivalent. (When interstellar travel is taking weeks or months anyway, a three-hour run at half a gravity, perceived as 1.5G for the first half and 0.5G for the second, doesn’t make much difference.) Planets away from the main world are often not used at all, or are used for mining.

* the GM reserves the right to make exceptions


I agree entirely. Carrying a lighter to unload cargo with is a deadweight burden that ends up on the freight rate, besides which the lighter itself sits idle for most of its life, making its amortisation expensive. And an IS spaceship that could land would be carrying around heavy and useless high-thrust rocket engines while travelling IS and repeatedly landing and re-launching its heavy FTL engine at needless cost in thrust and propellant. I’m sure that the Swiss army ship is an even worse solution than carrying a lighter in an external clamp.

The result is that the poorest worlds (with type N spaceports) pay the highest freight, which inhibits their trade and makes it hard to justify building the G facility that would reduce the freight rate, increase trade, and justify itself.

The eternal question of interstellar economics is “what is worth carrying”, and I suspect that things which on most worlds are imported cheaply will simply not be findable on an N-class world.

I always point out in this conversation that

  1. Australia both imports wheat from and exports wheat to Canada. Reason? Australian wheat flour is good for making bread and pasta; Canadian wheat flour is good for making cakes and biscuits. The slight difference in the relative productivities of growing soft and hard wheat in Australia and Canada are sufficient that it is better in Australia to grow hard wheat and sell it to Canadians to get money to by soft wheat, than to grow soft wheat our selves.
  2. Australia’s main exports are dirt and rocks. (Haematite, bauxite, coal.)
  3. Australia imports cherries from California and asparagus from Mexico (when they are not in season in this hemisphere) air freight, on some of the longest air routes in the world. They don’t even end up terribly expensive in my supermarket.
  4. The UK imports fresh¹ fruit and vegetables air freight from Uganda.

One day I must sit down with GURPS Spaceships and figure out what the fares and freight rates in Flat Black ought to be.

I do note though that in Flat Black one thing that is always worth delivering is humanitarian and development aid.

¹ No-one knows what the English do to them when they arrive.


ObRealWorld: I have a degree in economics, though I’ve only ever used it for gaming.

Of course one starts to wonder about the interstellar trade in services (or, to look at it another way, zero-mass goods). I know quite a few contractors here in the UK who have never met their accountants, but who post them a package of receipts every few months and do everything else by phone and internet; those accountants could be in Bangladesh, as long as they had the relevant professional qualifications which are specific to the UK. (In some cases I suspect they have the professional in the UK and the back-officer workers in Bangladesh.) But without fast and fairly cheap communications, that doesn’t work as well.

I assume Flat Black has no communications faster than ships. That’s true of Tempt Not the Stars too. Wives and Sweethearts has small courier ships with big laser/radio arrays, which sit near the jump point and pop through if there’s something urgent to retransmit; so the fastest a message can go is the lightspeed transit time between jump points across each system, so that’s hours to days. In practice ships usually wait a few hours between transits, so that’s a slightly longer delay, and isolated systems may not have a permanent courier on station at all – but it’s still a lot faster than material goods can travel.

So what are data that you can trade in?
Personal communications
Business communications (services)
Cultural goods (poetry, TV, holographic sculpture, etc.)
3D printer templates


I also have a degree in economics. I used mine for ten years research work at the [Australian Commonwealth government] Bureau of Transport Economics, studying road traffic mostly. But that ended sixteen years ago and my skills are pretty rusty.

You are correct in your assumption that Flat Black features no interstellar communications faster than ships, and that this puts a harsh damper on the interstellar trade in services.

As for 3D printer templates and so forth, one of the features of Flat Black is a rich public domain. Every design that was ever published, every expired patent¹, every set of fabricator instructions that ever got put on any net anywhere, is available free. The Technology Transfer Assistance Service (a branch of the Assistance Services Department of the Empire’s Colonial Office) distributes them zealously, except for weapons specs (which you have to obtain privately).

¹ The patent on the Eichberger drive never expires. It is perpetual by treaty.


You, me, Phil Masters… I’m starting to think this is a trend.


The trade in two different kinds of wheat seems like a really classic example of comparative advantage. . . .


It is a beautiful example, especially because until the 1980s the Australia Wheat Board forbade the growing of hard wheat in the southern parts of the Australian wheat belt, in order th ensure a supply of soft wheat for making cakes and biscuits. The Hawke government abolished its power to do that. The result was that Australian consumers got low-protein flour cheaper and the farmers who had previously been compelled to grow it for them got increased yields and prices. Both growers and consumers obviously benefited. So there was a direct comparison possible without resorting to hypothetical alternatives and revealed preference.


It may be a beautiful example but I don’t think it is true. For the last 30 years I’ve been part of the buying and breeding of soft wheat for Australia’s biggest user of soft wheat and we have never used Canadian wheat. In fact I have records going back to the 1950s and there is no sign of us buying Canadian wheat. Twice during bad droughts we have imported soft wheat and both times from the UK. Also hard wheat has been grown in sth NSW at least since the 1950s when my company first became worried that insufficient soft wheat was being planted.


Thanks for the correction. I don’t like to perpetuate myths (even ones I was taught in Economics lectures) and appreciate help in stopping.

Do you happen to know whether other participants in the market had the same experience as Arnott’s?


Well Arnotts buys about half of the domestically milled soft wheat, and the export market is only the small time container market - so what happens to Arnotts is what happens to soft wheat. We are the only soft wheat end user who contributes to soft wheat breeding. 25 years ago Westons used about 1/2 as much as us but then they closed their biscuit factories and sold most of the brands to us.


I don’t know the specifics of your setting, but have you factored in the cost of radiation shielding? Planetary masses and habitable atmospheres provide a lot of protection. My “Traveller-style” setting avoids orbital facilities and long (~years) duration spaceflight, primarily due to accumulated cosmic ray dosage.

Ports tend to use surface-to-orbit tugs pushing cargo in standardized farings that double as containers on-orbit. Small interstellar space planes carry cargo (at five times the deep space rate) to outposts too small to support their own tugs. Since most of these are under development, large deliveries are made by periodic dead-drop of cargo containers.


My feeling is that if you have enough starlift capacity to bring in a bunch of colonists (FTL in this setting generally involves crossing several AU of real space at each end), it’s fairly cheap to take apart an asteroid and put some of its mass as shielding material in orbit.

(Also, some degree of anti-radiation nanotreatment is close to universal among people who live or work in space.)


Oh, certainly. I have a couple orders of magnitude fewer emigrants in my setting than Flat Black, and much less ambitious real-space drives.

Anti-radiation treatments are an interesting point. My (medical layman’s) feeling is that any regimen that would address chronic radiation syndrome and cancers from cumulative exposure would be at most one or two steps away from true anagathics, due to the need for comprehensive cellular-level monitoring and repair. I’m not sure whether I want that in my setting.


Well, I talked about that a bit in a different post - I’m using quite a bit of GURPS 4e TL11, and in Wives and Sweethearts I’m happy with having fairly substantial life extension.

(At the very least, a generalised anti-radiation treatment is likely to include cures for most cancers.)


Have you read any of Elizabeth Moon’s Heris Serrano/Esmay Suiza novels? There’s an interesting treatment there of the administrative and career dynamics of a navy where careers last most of a century.


Yes – they were loosely influential but it’s been a few years.


Here’s draft text on the subject for the new setting book.

Spaceport facilities

Size codes

0 — world sees less than 10 tonnes per day of surface-orbit traffic, at all spaceports combined.
1 — ” 10–99 tonnes per day ”.
2 — ” 100–999 tonnes per day ”.
3 — ” 1,000–9,999 tonnes per day ”.
4 — ” 10,000–99,999 tonnes per day ”.
5 — ” 100,000–999,999 tonnes per day ”.
6 — ” 1,000,000–9,999,999 tonnes per day ”.

Type N: no facilities

The world sees so little traffic and supplies such primitive resources that it cannot support even a single orbital shuttle, flight crew, and ground crew. A shuttle may be mothballed in orbit, starships bringing crew and consumables to use it, otherwise ships must bring their own shuttle. Cargo may be delivered in disposable soft landing kits; personnel may arrive in personal re-entry capsules.

Type G: ground facilities

A shuttle or small fleet are hangared and serviced on the surface. Passengers are loaded and unloaded in a shuttle with a passenger module or a dedicated passenger shuttle. Export cargos may be assembled in orbit in preparation for loading; import cargos may be unloaded in orbit and landed progressively over days or weeks.

Type O: orbital port

There is at least one orbital facility where passengers may assemble for boarding and wait for shuttles after disembarking, more or less continuously served by shuttles from the surface.

Type L: launch facility

There is at least one non-rocket spacelaunch facility. Small, fast-rotating worlds built geostationary elevators; others built rotating-tether skyhooks, but are demolishing or have demolished them. Launch loops are standard, delivering traffic in cheap orbital vehicles to orbital up-ports.


I care perhaps too much about infrastructural details.

Classic Traveller spaceport codes (and GURPS similarly) seem to be aimed at the group with their own ship: where can you get annual maintenance done, or damage repaired? In a setting like this that’s a bit less ship-orientated, “how can you get between your ship and the surface” seems like a more sensible starting point.

I can picture some special cases of O where everything is kept on the orbital facility by default: a prison world, for example. (Do you have those?)

When I look at launch loops I think “about as much energy as a small nuclear bomb, right next to lots of expensive things on the planet”. Yes, I know, safety engineering has to improve anyway in order to get the thing built at all.


High tech transport is very scary, which is the insight that got me to the Empire in the first place.