Corridor Worlds


The Corridor, from Esperanza to Gateway.

The Corridor was originally a backwater – a branch off the Main, controlled by the Xa Imperium. When humans colonised Esperanza (1518) and then Bessel (1417), the Xa incorporated them into their empire. Soon, however the Esperanzans rebelled, and over nearly four centuries of warfare, they eventually expelled the Xa from Corridor altogether.

Bessel (1417 B765547-9 pop=300k)

Dark green poisonous forests, jungle, desert.

Bessel is the second planet orbiting 61 Cygni-A at a distance of 0.65 AU. It was colonised via sub-light directly from Earth, although jump drive enabled early explorers from Esperanza to survey the planet before the colony ship Marinus Van Der Lubbe arrived. The planet has a lush vegetation that is highly poisonous to human and Xa alike. The Imperium had only a small landing field located in one of the planet’s deserts.

When the colonists arrived, they decided to embark on an ambitious programme of forest clearance and soil sterilization. While this approach has been successful, the colony has grown painfully slowly.

Today, a communist government rules the planet by popular consent. They maintain a small but capable starport that is a popular stop-over for traffic heading out from Esperanza. Bessel is a member of the loose “Commonwealth” that was established by Esperanza during the struggle to drive the Xa out of Corridor. Besselers are terrified of an Esperanzan take-over. The Next Step party is growing in influence, but so far the Communist party has managed to hold on to power.

Voy (1416, C000697-7 pop=8m)

An asteroid belt that orbits the red dwarf star Gliese 1. Voy used to be a backwater. A few prospectors would come here, seeking out magnetic monopoles or beryllium crystals, but few stayed permanently. That all changed when the J1+ drive was introduced. Suddenly Voy was only two weeks from Gateway (1414) and the system became a major transit stopover.

The starport is large, but basic. At its core is an ancient Xa military base, built into a large asteroid. Major industries are deuterium extraction & haulage from the system’s three gas giants, and He3 gathering/processing from the asteroids. The Commonwealth navy has an observation hub here – it collects intelligence data from all through the Xa Imperium and the Long Republic. Several secret projects are also rumoured to be based here.

Nebelwelt (1216 C597523-6, pop=800k)

Dark green forests, mountains, jungle

Nebelwelt is a third planet in the Gliese 892 system. Formerly called Xa-Gol, the Xa inhabitants were evacuated as part of the armistice settlement that concluded the 2nd Xa War. Humans from Bessel (1417) established the new colony, which they called “Nebelwelt” (Mist-World).

The world has lush vegetation, a dense atmosphere and wide oceans. The atmosphere is often filled with fog or mist. There are many flying creatures, some of which are quite hostile.

Today, Nebelwelt is a sleepy agricultural world. Commonwealth forces have seized control of the starport, which is an important stopover for Jump-1+ craft en route to Teowahaha (1017). Year Zero has not yet made much difference in the rural outback. The jungle-choked ruins of the abandoned Xa towns are shunned by the Nebelwelters, but are a minor tourist attraction for visitors from the starport.

Mirfaq (1115, C532243-6 pop=200)

The Commonwealth maintains a starport on Mirfaq (ยต Cassiopeiae) as a service to shipping. There is no other convenient source of deuterium fuel in the system, so jump-1 ships are forced to land there. Processing fuel from the planet’s shallow seas is the one main industry. There is a small archaeological team studying Xa ruins.

Cassiopeia (1315 C7B1867-6 pop=400m)

Hell-hole with thick, corrosive atmosphere. Acid rain.

For a century, η Cassiopeiae was the Commonwealth’s frontline against the “Xa threat”. The system was captured during the 3rd Xa war, giving the humans a beachhead only one jump from the bastion at Xa-Arrack (Gateway – 1414). Despite the hostile conditions, great effort was put into expanding the colony – which had been a modest Xa mining base.

After Xa-Arrack itself was captured during the 5th Xa war, Cassiopeia remained the Commonwealth’s military “backstop”. Naval squadrons are stationed here, ready to strike back at any Xa encroachment on Gateway.

In the subsequent years, trade florished and Cassiopeia became a crucial stop-over on the Corridor – the last major, safe human colony before alien space. At its peak, its hiring halls rivaled those on Junction (0712). Much trade still comes along the Corridor, but the J1+ drive has enabled many human ships to bypass it altogether. That’s undermined Cassiopeia’s importance, and lead to a catastophic recession.

Today Cassiopeia is wracked by unemployment, crime and falling population and living standards. Recruiters for semi-legal indentured labour services have offices in all major settlements.

Gateway (1414, C8B068A-5 pop=9m)

Formerly called Xa-Arrack, this planet lies in the Gliese 33 system. Gateway is a hot desert world with a thick corrosive atmosphere that orbits only 0.3AU from its star.

For centuries Xa-Arrack was a fortress, built up by the Xa Imperium as their last line of defence against the Esperanzan Commonwealth. The Xa wished above all to keep humanity bottled up in Corridor, preventing them from accessing the Main. Eventually Xa-Arrack fell, and the human “genie” escaped its bottle. The Esperanzans renamed the world “Gateway”, and used it as a springboard from which to launch further attacks on the Xa.

Today, Gateway is a highly controlled frontier world. The Xa lie only one parsec away on Xa-Maxin (1514), and the Long Republic’s nearest world, Vorposten (1413) is also only a parsec away. Traders from both directions use Gateway as a meeting point, and marketplace. There is a vibrant, if closely controlled, merchant quarter. This is the most exotic place most humans of the Core worlds will ever see. Goods from up and down the Main are available to buy. There are aliens from a dozen species living here, and even stranger visitors regularly pass through.

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  1. alex said,

    15 December, 2014 @ 11:03

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    Matt Fitzgerald You mention in several world descriptions Deauterium extraction and hydrogen refuelling. Do jump drives run on hydrogen even if antimatter is plentifully available ? The energy density of antimatter is so much greater than hydrogen fusion that if you can run the jump drive on antimatter it frees up much more of your ship for, for example, cargo space.

    Unless of course it is some special property of hydrogen that makes the drive work – I can buy some kind of resonance effect between large masses of fusing hydrogen being used to enter the jump chord.

    Matt Fitzgerald Mirfaq – There’s nothing in your described jump physics that prevents a J1 ship from having extra large fuel tanks, making a J1 trip from Beta Hydri to Mirfaq, moving straight to the next jump point, then jumping on along the chord to Ararat.

    Depends how close Mirfaq is to the jump points. In fact I could see some systems operating the other way around – provide free fuel to ships that visit and stop over for at least a few days in order to keep up trade (like those ‘cheaper if you stay for the weekend’ flight deals).

    Alexander Tingle There are three commonly used fuel sources. Deuterium/tritium fuelled fusion (TL9) is commonly available. The fuel can be obtained directly from oceans or gas giants. Antimatter (TL9) is also commonly available. As you say, the fuel is incredibly energy dense, but it’s only available by trade. Deuterium/helium3 fuelled fusion power (TL11) is available to Core world humans. The fuel is about as energy dense as DT, but the power plants can be much, much smaller, because they need much less radiation shielding. However, He3 is relatively rare – it needs to be prospected for and laboriously extracted from asteroids or airless moons.

    So, an human exploration vessel would probably use DT fuelled fusion, because the fuel is much easier to obtain. It might have He3 fusion powered small vehicles and devices. It might also mount an antimatter power plant, but relying on that exclusively might be a bit risky.

    Fusion “rockets” are available at one TL lower. So TL8 has DT fusion rockets, and TL10 has He3 rockets. Rockets are high-thrust short-burn drives, usually only used for take-off/landing. The point being that He3 will probably be available for purchase at TL10 worlds.

    Alexander Tingle Mirfaq – Yes, but Beta Hydri is barren. It has absolutely no fuel source in the inner system. You can waste weeks or months travelling to the outer system to refuel at the gas giant, or you can go straight on to Mirfaq and refuel there – for a price.

    Of course, you could also carry enough fuel for three jumps in a row, but that really is starting to eat into your cargo space.

    Matt Fitzgerald Good point about Beta Hydri. Until some enterprising soul decides to set up a refuelling station in the inner system there. And those nice folks on Mirfaq decide to hire some deniable foreigners to arrange an ‘accident’ for it

    Tony Jones You could have an operation setting up a fuel extraction facility at the gas giant which sends bladders or somesuch of fuel on slow, energy-efficient orbits to the inner system, where another base would intercept them and sell them to the passing trade. Once the initial setup period is over the slowness of the transit time for the fuel from gas giant to inner system become irrelevant because bladders are always arriving. As long as an investor is willing to think long-term enough, this cuts out the travel time restrictions to the outer system and probably undercuts the costs of shipping fuel up from a planet…

    Alexander Tingle I did extensive cost/benefit analyses on just that scenario (and several others) for my (abandoned) TCS campaign. Let me see… Ah here we are.

    C: 100t, 1G ships cost : Cr85 / (Higher G ships not cost effective)

    K: 1000t, 1G ships cost : Cr41 / (Cycle time to skim fuel + accelerate a drop tank up to 30km/s @1G: 12hr)

    - Nearby GG                  : cost     : volume
      K-ship: 2d round trip        : Cr 82/t  : 440t/d
      C-ship: 2d round trip        : Cr 170/t : 27t/d
    - Average GG
      K-ship: 39day/78tank relay   : Cr 80/t  : 1800t/d
      C-ship: 39day/78tank relay   : Cr 125/t : 110t/d
      K-ship: 5d round trip        : Cr 205/t : 180t/d
    - Distant GG
      K-ship: 230day/460tank relay : Cr 270/t : 1800t/d
      C-ship: 230day/460tank relay : Cr 315/t : 110t/d
      K-ship: 12d round trip       : Cr 490/t : 75t/d

    So for a low-traffic port that only needs a few dozen tonnes of fuel per day, it’s best to have few ships just shuttling back and forth. Your “tank relay” scheme is most cost effective when the GG is far away, and the port needs a lot of fuel. The purpose of this table is to give an idea what fuel might cost in various different situations.

    Importing fuel from 1 parsec away costs 800Cr/t,. so that (plus profit margin) establishes a rough ceiling for fuel prices.

    (Can you see why I call this game Accountancy Quest?)

    Andy Miles In KSR’s “Mars Trilogy” he has the non-stop shuttles running between the colonies; these use slingshot maneuvers to turn around at either end and so don’t need to slow down. Local ferries come out to meet them and drop off or collect cargo/passengers. Because the shuttles don’t need to decelerate they can go twice as fast as they would if they actually stopped. This is, of course, more economical if you need to move cargo/passengers in both directions.

    Alexander Tingle People need more living space on long journeys, so that kind of works for passengers. For pure cargo, there’s no need to have a “ship”, you can just throw it at the destination and let it drift there on its own.

    Andy Miles What are you going to use for the initial push? Simple rockets? Mass drivers?

    Tony Jones I’d suggest mass driver, maybe powered by running wires through the magnetic field of the planet.

    Tony Jones One of these:

    Andy Miles So with mass drivers are we talking weeks, months or years for the cargo to arrive? What if you have a need to deliver a time sensitive cargo or passengers? Does a non-stop shuttle service then make sense? So let us say you have a substantial mining operation in the outer system, it sends packets of cargo home via mass driver. If you have a continuous shuttle that can do one leg of the journey in a week then that can be used for personnel rotation and can carry smaller time sensitive cargoes or items for which the need arises unexpectedly. Presumably the only real limit on the speed of the shuttle is the ability of the interface shuttles to meet up with it at either end.

    Alexander Tingle Are we talking traditional Traveller, Ad Astra, or real life?

    Andy Miles Primarily Ad Astra as that is the main topic but feel free to add additional observations

    Andy Miles So are your times, above, assuming that the journey is only one way and that the vessel accelerates up to a mid-point and then decelerates for the remaining half of the journey?

    Alexander Tingle Well, in Ad Astra the best thrusters available to humans (without antimatter) can continuously accelerate at 0.1G for at least a month or two without refuelling. Travelling to the outer system takes about a month.

    A mass driver would accelerate the cargo in one initial burst. It needs high quality energy, in the form or electricity, and it needs a huge amount of it all at once. Honestly, I don’t see the advantage. A “direct” fusion drive (where the hot gasses get vented out of the back to generate thrust) must be more efficient than generating electricity, and then using that to generate thrust. I can’t see how Tony’s electrodynamic tether brings anything to the party. It is basically a big battery – you accelerate your craft into a higher orbit, and then later turn that energy into electricity. If you are just going to use that electricity to accelerate something, then I reckon you might just as well have cut out the middle-man.

    Alexander Tingle The times above are for the TCS campaign, with Traveller-style M-drives. 1G drives were the most cost effective, unsurprisingly.

    Andy Miles So, another idea from the “Mars” books (I’m mid way through reading them at the moment) is to use the momentum from the spaceport atop the space elevator to launch objects.

    Alexander Tingle I think the availability of continuous thrusters with a reasonable acceleration renders a lot of such tricks redundant.

    Using the spaceport’s momentum to launch things is just another type of energy storage. Once you’ve launched your thing, you then have to “recharge” the spaceport by speeding it back up again. If your drives are inflexible, then perhaps that’s worth it. Perhaps you can generate power more efficiently on the ground, and beam it up to the spaceport. But if your space drives are efficient to start with, then I don’t see why you wouldn’t just use them directly.

    (That’s good from a dramatic perspective too, of course.)

    Andy Miles The idea is that the spaceport is a hollowed out asteroid weighing in at several billion tons in a geostationary orbit about 35000km above Mars. About half of the mass of the asteroid has been mined for the carbon to make the tether cable; what remains is used as the counterweight and the spaceport. A ship docked at the spaceport simply releases at the appropriate point in the spaceport’s orbit and essentially gains the benefit of having performed a slingshot maneuver as it launches. Whilst my science is rubbish (as I continually amply demonstrate) I can’t see that a ship with a displacement of a few tonnes to a few hundreds of tonnes would slow down the progress of the spaceport in its orbit.

    Alexander Tingle This is at the top of a space elevator right? I think it’s pretty important that the counterweight remains in an orbit that is precisely aligned with the planet’s rotation. Even a slight difference will cause the top of the elevator to start to “lean”, which isn’t good long term. The top will therefore need to be powered, to keep it in the right place.

    Matt Fitzgerald Efficient long burn thrusters do seem the way to go. Don’t forget that for ‘Inward’ travel you can just slow your orbital velocity and let the stuff ‘fall’ in system.

    In particular I am thinking of capturing icy asteroids and dropping them to the jump points as fuel sources.

    Slow-tug pilots – the unsung heroes of the space economy

    Alexander Tingle You are right. I think that “civilized” space will have a lot of these conveniences. It will make for more of an interesting contrast one you get out to the “wildnis”.

    Alexander Tingle The best way to bring things in system might be to give them a “gentle” boost towards a distant dwarf planet such as Pluto, and then use that to slingshot them in to the inner system. If there’s another planet in the inner system that you can use to slingshot them out of the transfer orbit, then so much the better.

    Andy Miles The space station/asteroid/counterweight is powered anyway as it has to be able to avoid Phobos or Deimos (can’t recall which – one of them has been moved) periodically. But, if what you say is correct (and I’m not doubting you for a moment) surely any space station mounted on a space elevator will need to be powered anyway – if craft are constantly landing and taking off surely the total mass will be constantly changing?

    Alexander Tingle I assume that’s the case, yes.

    Alexander Tingle Space elevators are quite common technology in Ad Astra. Both Earth and Esperanza have one. Skyhooks are also common:

    Andy Miles Rotating or non-rotating? With the elevators in general…what sort of speeds will the elevator cars move at? And more generally…how common is space travel? Can the average person expect to engage in space travel at some point or is it still comparatively rare?

    Alexander Tingle Rotating. No idea how fast the elevator cars move… fast enough? I guess the availability of space travel varies. Most Core world (or Xa) citizens will never experience it. On less populated world, it’s more common. In the Long Republic, a huge minority of the population lives in starships (although they have a technical advantage).

    Andy Miles Speed could be very relevant if the cable is 35000km long. Sorry to keep harping back to the “mars” books, but there it can take the best part of a week to travel up the cable and the cars become, essentially, small mobile hotels. They could be an interesting locale.

    Alexander Tingle Don’t apologise. It’s a fair point. Wikipedia confirms your estimate of 5 days to climb the tower.

    Andy Miles That could give you a setting not unlike a long distance sleeper train (Trans-Siberian Railway analogy). Characters may have to deal with other passengers and, unlike paying passengers aboard a PC ship, the PCs don’t call all of the shots or have control over the environment. Its also a means of transport that PCs are likely to use of their own accord, they don’t have to have their arms twisted into taking the long distance mono-rail train.

    Matt Fitzgerald Accountancy Quest would suggest using standardised containers for space elevator transport that are detached at the top, picked up by orbit tugs for a shove toward the jump point, then corralled and loaded into jump tenders. No reason low berth passengers can’t go the same way.

    Space Tetris ftw !

    Andy Miles That reminds me, meant to ask if we have “Low Berth”/cryogenic sleep or whatever you care to call it? Anyone fancy a Hollywood style climbing over the roofs of railway carriages transposed to a space elevator?

    Alexander Tingle Low berths do exist, just as they do in standard Traveller.

    Andy Miles Can we have a bit of background, perhaps in a new thread, of what exactly is in and what is out in tech terms? I know you’re tinkering a little with standard tech levels and giving spiky tech profiles.

    Alexander Tingle @Matt – it’s better than that. You can travel past the midway point of the elevator, and let go right at the top. Then you get flung away from the planet at up-to several km/s. I think that was what Andy was trying to tell me before. I suspect the energy comes from the spinning Earth, via the elevator car pulling itself up the cable. Sorry Andy – I was probably talking bollocks, earlier.

    Alexander Tingle My stuff on tech levels is a bit too disorganised to be published yet. I need to make a “players'” version of it, too. Maybe later. I’ll try to give you a flavour here…

    Andy Miles It wasn’t quite what I meant – I did mean that you dock with the spaceport/upstation/counterweight and then when you undock you get flung into space for free.

    Alexander Tingle So, not available:

    Grav tech (although the Long Republic has this.) Meson guns. Regular Traveller M-drives (that’s just grav tech, again) Superdense armour Deep radar

    Alexander Tingle Available only to Procyon (new tech they’ve recently invented):

    • Jump-2
    • Nuclear dampers
    • Stasis fields (time is frozen inside the field)

    Andy Miles I’m assuming that most things TL 10/11 (possibly 12) are available?

    Alexander Tingle Available tech not from basic Traveller:

    Antimatter Slow fields (like stasis fields, but not as good) Grid energy (from the Culture novels – it’s free energy, but only very low power. Basically, your mobile phone can run forever without batteries.)

    Andy Miles So is a “Slow Field” used as something like a safer version of Low Berth?

    Alexander Tingle Stasis fields can certainly be used like that. Slow fields aren’t slow enough. I think you would be better off using a slow field to wrap your entire passenger section – then the journey will seem to be quicker to passengers, and they will use less food/water/air.

    TBH, I’ve written down that slow fields are widely available to Core world humans, but I’ve not given any thought to the implications or common uses. Suggestions?

    Andy Miles Apart from the obvious you could spend the equivalent of a day or two per week in one and extend your life over a greater period. What would be the “exchange” ratio for slow time:real time?

    Alexander Tingle Nothing too extreme. Up to 3:1, say?

    Andy Miles People who spend significant amounts of time in a slow field will age slower than those who don’t. Therefore family units wouldn’t/couldn’t work very well if some members of the family spend significant amounts of time inside the field and others don’t. Therefore starship crews are often family affairs and double as family homes; it’s not unusual to find several crew members are married/in semi-permanent relationships and bring up their children aboard ship. In general ships’ crews will grow apart from those who aren’t ships’ crews; they will however retain old customs for longer.

    Andy Miles Starship ownership/operation may even become semi-communal maybe?

    Alexander Tingle I could certainly imagine slow fields being used in jump space. As for families living in space – that what the Long Republic does. (The LR essay is scheduled for Wednesday.)

    Matt Fitzgerald @alex – I think you underestimate how much many people use their mobile phones

    Slow fields – Pretty much all ‘dead time’ activities. Jump travel, in system travel, commuting, waiting for the chronically disorganised, 99% of all meetings.

    Ambulances. Prolonging the life of those awaiting transplants / regrowth of vital organs / development of treatment / rich and afraid to die. Prolonging the life of those with knowledge or expertise deemed vital to the state (whether they like it or not).

    Transport of perishable items, either as an augmentation to or replacement for refrigeration, especially for high value luxury items.

    Tony Jones My point with mass driver etc is to make it as cheap as possible. The cargo in flight is dumb boxes. The launcher needs no reaction mass and has a minimum of moving parts. The flight times of the cargo is irrelevant once the system is set up as long as the departure/arrival rate is sufficient…

    Matt Fitzgerald Nuclear dampers – these are as world changing a technology as the development of nuclear weapons, although less so in a milieu with common antimatter access. Granted they aren’t hugely effective when first developed, but if one side in a ‘Cold War’ style conflict develops them and the other side finds out (and can’t steal or replicate the technology) then they are likely to contemplate ‘pushing the button’ before their nuclear deterent is reandered obsolete.

    Alexander Tingle @Tony: My point was that if you have an efficient continuous thrust rocket, you might as well use it to drive the payload directly, rather than using it to lift your mass driver into a higher orbit in order to power the electrodynamic tether in order to power the mass driver.

    OTOH, if there isn’t much call for traffic in the opposite direction, then ships will be returning empty, and that’s pure waste. So as long as the efficiency of the drive->tether->mass driver arrangement is >50%, your way would win.

    Alexander Tingle Nuclear dampers are credited with saving Procyon from the Commonwealth’s naval assault, (a few months prior to the start of the game).

    Andy Miles Alex, did you have a specific purpose in mind when you decided to incorporate slow fields? Seems a bit of an odd thing to throw in completely at random so I presume there was some thought behind it.

    Alexander Tingle They belong on the same tech level track (dimensional engineering) as jump drives. Core world humans are further along that track than anyone else. It makes sense that certain advances lead to others. I feel it would be a bit weird if humans had better jump drives, but zero other advantages.

    Similarly, the Xa have much better nanotech than humans. The Long Republic has grav tech, which is completely baffling to Xa and human scientists alike.

    Alexander Tingle Traveller’s tech level track is extremely boring and conservative. It doesn’t allow for most of the interesting “sci-fi” technologies. As space opera, I want Ad Astra to have much more speculative technology. Dividing it into tracks makes it possible to wow players with impossible high-tech gizmos, even while they themselves are wowing the aliens they meet.

    Andy Miles Yes, I get the divergent TL idea. I just sort of assumed that you’d got something quite specific in mind for slow fields or you wouldn’t have mentioned them and they’d be little more than a curiosity. If slow fields are sufficiently cheap could they be used for general preservation of (insert item here) much as fridges are used to preserve food?

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