CT Only: Stellar Masking

[Supplement Four]

I was reading Timerover's question IN THIS THREAD, and it made me think of something that is often ignored in CT. Stellar Masking.

Building on Timerover's question...

Isn't it possible that a certain route--a jump between two worlds--becomes economically non-viable due to the stellar masking?




If you've got a starting point where it takes several days or more to reach a point where the ship is outside of the 100 diameter limit of the system's star AND outside of the same limit from one of the system's bodies (could be a different planet than the main world), and the destination system is similar, then you could be tacking on one to two weeks MORE to the trip to that world.

Life Support costs are 1,000 Cr per person per week.

This could also eat up your Power Plant fuel pretty quickly.





STELLAR MASKING

I guess there's no way to really easily refer to stellar masking in the game. The easiest way, I would think, is to figure the system's star (stars), and then use Book 6 to determine the distance to the habital zone and compare that to 100 x the star's diameter. That way, you can figure an orbit number that gives you a playable rule of thumb showing what part of the system is masked by the star.





FROM A GAME PERSPECTIVE

This might be the very reason that players risk a misjump in a game, jumping within the star's 100 diam limit (and heaven forbid if they jump within 10 diams of the star).

 

[GypsyComet]

Because star systems are not all orbiting on the same plane like the teacup ride at Disney, stellar masking remains a plot device.

 

[Supplement Four]

Because star systems are not all orbiting on the same plane like the teacup ride at Disney, stellar masking remains a plot device.

If you map the system, as is done with Book 6, then you know the star's diameter and the distance from the star to all the system's worlds.

See page 56 of Book 6. It wouldn't be that hard to draw a line to show what part of the system was masked.

Elliptical orbits, where part of the orbit takes the world outside of the star's masking would be rare and close to that line drawn. (And, this would be a pretty cool thing to put into a game, where a world has a season outside of the stellar masking.)

Habital Zones aren't usually that wide, when speaking of orbits.

MT's SOM has a nifty chart for rolling near-side/far-side positions (which can just about double time in normal space operations sometimes).

 

[Supplement Four]

It would be interesting to take an official subsector, like the Aramis subsector from TTA, and look at system, defining the stellar masking of each.

I wonder how it would change the adventure.

 

[McPerth]

Life Support costs are 1,000 Cr per person per week.

Just one punctualization: Life Support costs Cr 2000 per two weeks. While it may seem the same, as I read it, it means that you must pay the full Cr 2000 even if you only use the stateroom for 1 week.

Off course, this does not affect the rest of your reasoning, keeping it equally interesting.

 

[mike wightman]

Is it worth the effort though? If you have an adventure in mind where the players are going to be doing something during the real space journey from the stellar 100D limit to the mainworld fair enough.

But if all you are doing is saying it takes an extra few hours to get from jump point to world and you are glossing over the additional travel time is it worth the added complexity?

Perhaps one of the reasons for all of those mainworlds built on rockballs is that they are the best place to put the starport, the rest of the system is being exploited for resources by insystem craft. Ther could even be a garden world 'deeper in the well', but the resource exploitation and factories are on the rockball beyond the stellar 100D limit.

Unless I am running an exploration or near future campaign I just ignore jump masking and reason that by the 57th century the mainworld you generate is the one that is most accessible in the system.

 

[whartung]

Because star systems are not all orbiting on the same plane like the teacup ride at Disney, stellar masking remains a plot device.

I agree with this.

The overall point is valid, but the mechanics of calculating it, maintaining it, etc. aren't worth the value to the game.

If it were all automated, that could be different (then there's "no cost").

In the lifetime of the players, the systems are essentially fixed in place, the details are the relationships of the individual planet orbits and time of year as to whether the masking is a factor.

And in the end, I bet if you take two "earths", 180 deg out of phase, and just plotted them each month, you could easily get a chart as to whether the systems were masked or not. The variances of the orbits would not be enough to matter in the time span of a typical campaign. And once you have it for one set of planets, you can simply rotate the chart and have it similar for any other two planets.

 

[GypsyComet]

If you map the system, as is done with Book 6, then you know the star's diameter and the distance from the star to all the system's worlds.

You can, but the easy version is that Inner worlds are almost always inside the stellar jump horizon, outer worlds are almost always outside of it, and Habitable orbit worlds vary according to plot need. Remember that for much of the CT run, star types were not provided.

From the other direction, it is also worth noting, again, that nearly all of Traveller's system generation processes assume that the orbital radii we see in our system are some sort of universal constant, which they are not.

But this misses my earlier point. Jump Masking by the star is most significant when the system of origin sees the target system edge-on so you have to go *around* the star to get to some subset of its worlds at any given moment. If real world astronomy is any indication, that's pretty rare.

It would be interesting to take an official subsector, like the Aramis subsector from TTA, and look at system, defining the stellar masking of each.

I wonder how it would change the adventure.

If we assume that radio works, the underlying premise of week-on week-off commerce is still viable, as you are calling brokers for loading and unloading as soon as your lag is acceptable, and using an email analog until then.

Looking at the 1116 stellar listing for Aramis via the wiki, there are relatively few Class M stars to gum up the habitable zone inside the stellar jump horizon, so the assumed travel times and panic departures do not appear to be hindered all that much.

 

[Xerxeskingofking]

It would be interesting to take an official subsector, like the Aramis subsector from TTA, and look at system, defining the stellar masking of each.

I wonder how it would change the adventure.

somebody made a list of mainworlds that are masked by their star in the Spinward Marches. its about 30 odd, and some of them are like 2 months from the jump limit at 1g.

given the non-linear way that travel time reduces at higher G rate, I am pretty sure some of those 66 days shadows would still be 7+ days deep even at 6g.

 

[McPerth]

I guess most (if not all) those worlds have some way of space station or any minor planet facility in the jump limit serving as main spaceport terminal, so that ships do not really rach the planet (unles they really need to) and can just load/unload caroes and passengers.

Once in this terminal, of course, fast shuttles take the cargoes or passengers to the planet.

Of course, this will afect their trade, as you need this extra time for any movement in/out the main planet.

Its effect on strategic plannning is also something to be counted on, as any fleet trying to attack th planet must stay in system for this long too, and risks being trapped there by reinformements arriving (as they may well need to stay over 2 weeks in system, time may be ample for them to be called and come). This also means that the population and SDBs have ample time ot ready for the incoming fleet...

 

[Supplement Four]

I guess most (if not all) those worlds have some way of space station or any minor planet facility in the jump limit serving as main spaceport terminal, so that ships do not really rach the planet (unles they really need to) and can just load/unload caroes and passengers.

An interesting idea. TL and Starport class would play a part in this, I would guess.

somebody made a list of mainworlds that are masked by their star in the Spinward Marches. its about 30 odd, and some of them are like 2 months from the jump limit at 1g.

given the non-linear way that travel time reduces at higher G rate, I am pretty sure some of those 66 days shadows would still be 7+ days deep even at 6g.

Incredible. That's got to have an effect on trade with that world.

 

[jcrocker]

I guess most (if not all) those worlds have some way of space station or any minor planet facility in the jump limit serving as main spaceport terminal, so that ships do not really rach the planet (unles they really need to) and can just load/unload caroes and passengers.

Once in this terminal, of course, fast shuttles take the cargoes or passengers to the planet.

Of course, this will afect their trade, as you need this extra time for any movement in/out the main planet.

Its effect on strategic plannning is also something to be counted on, as any fleet trying to attack th planet must stay in system for this long too, and risks being trapped there by reinformements arriving (as they may well need to stay over 2 weeks in system, time may be ample for them to be called and come). This also means that the population and SDBs have ample time ot ready for the incoming fleet...

If a system was close to the Extents, a deep-space transit point would be a very tempting target for the corsairs. If it's a low-tech agricultural world, they might not be able to afford the big SDB squadron they'd need to protect it.

This came up in our campaign, given the data we decided that the shipments were on big merchants, the sort they had in the Traveller Adventure, 3000 or 5000 tons displacement, and they had at least 2G drives, or else it really would take forever.

Not many Beowulfs stopped by.

 

[McPerth]

Let's put Menorb as an example (as I find it an specially interesting case):

As shown in TTB:

Menorb 0203 C652998 7 Poor No GG.

As given in the list Xerxeskingofthekings gave us, it would take over 66 days to reach the main world fro mthe jump limit. Also being next to the Extents, the corsair problem cannot be ruled off (as pointed by jcrocker), and single ships performing the long trip from jump point to mainworld could become tempting targets (OTOH, such a corsair would be trapped there for some time too, and even might need extra fuel if they go too far inside the gravity well)

For this post, I'll assume the rules given in CT:LLB5 (high guard) page 20 are in force:

alternatively, a planetary navy may construct ships on i t s planet, using local resources, even if a shipyard is not present

With itss TL 7, it cannot build any quick spaceship 2G being the limit. So we can asume they have have those 2G ships used as shuttles if they want to keep any interstellar trade.

OTOH, Starport C allows for repairs to be done there. As you can hardly expect a damaged ship to make this long run, the only option, again IMHO, would be some kind of space station where they can be performed (to the best of TL7 capacity).

They can neither build (and having Poor trade clasification, probably cannot aford) a strong SDB fleet (as an aside, its SDB fleet is rated at 50 in FFW, larger than many other systems :CoW.

So, my guess would be they organize large comboys, escorted by some SDB, to regularly make the run from the station to the mainworld, taking the passengers and cargoes. Each such comboys will tke several weeks of travel time. They may have some high speed shouttles for priority cargoes (or those passengers that can afford them).

Of course, this would add significant time (and probably costs) to any movement in/out Menorb, making it a true backwater system, despite its large pop.

Some side comments about this situation:

• Maybe those added costs have something to do with the system being Poor (albeit the reasons for this trade classification are not related to them).
• All those reasons should be a good reason to try to improve their TL, but at the same time a true indrance to this goal
• Even assuming its TL was even lower in 623, the surprise invasión/coup performed then by the 4518^th LIR (see SMC, page 38) would be unlikely to be possible if they need several weeks of travel from jump exit to mainworld...

 

[jcrocker]

Granted that having 'deep' systems would add to the travel time, but for the goods themselves, would that matter?

If it's an agricultural planet, they grow food. If you've got a couple of weeks to the jump point, none of it will be carried fresh, granted, but there's still frozen and concentrate and many other ways to get nutrition to the people that live on the high-pop worlds with trace atmospheres that can't grow oranges in sufficient quantity. If it's grains, then you can make it into flour or carry it bulk. Today grain ships from North America can take a few weeks to get to, say, Russia - but they allow for that, and it's just part of the logistics planning.

If it's manufactured goods from a high-tech world, you don't even have to worry about freshness in most cases. Medial radioactives have that issue, but then they wouldn't be made on that planet for interstellar export.

Since just-in-time manufacturing simply cannot happen across interstellar distances, it's mostly the ships and their mortgages that would come into play. If a world is one of the ones listed in a 'deep' system, they'll pretty much have to go through those regular runs that the various merchant rules imply exist, there won't be much or any of the tramp freighters hoping to get that fantastic load.

That's if there's something that the world produces that the rest of the Galaxy wants. If not, then it's probably a backwater.

 

[Supplement Four]

I like that term, "deep systems".

Another issue for deep systems are X-Boats. With no M-Drives, are there Scout stations outside the masking region to accommodate the major X-Boat Lanes?

 

[McPerth]

Granted that having 'deep' systems would add to the travel time, but for the goods themselves, would that matter?

Having to ship your cargo about 2-4 weeks more in normal space to reach the station for transhiping to a starship will surely have a cost...

Another issue for deep systems are X-Boats. With no M-Drives, are there Scout stations outside the masking region to accommodate the major X-Boat Lanes?

I guess they will be handled by those Space Stations I assume to be there. Some of them may be Scout managed, of course.

 

[mike wightman]

It will, but it is not something the original trading rules were designed with in mind.

The original trade rules are built around a ship spending one week in jump and one week landing from the 100D limit, unloading, finding a new cargo, finding passengers, refueling, (optional - seek out a patron and have an adventure), flying to the 100D limit.


If you add jump masking - which is not present in the original rules - then you also have to add an outersystem starport catering for the jump traffic in order to maintain the two week trade mini-game. This would rapidly become the 'mainworld' for intersteller traffic.

This implies a comprehensive system of insystem haulers, which are nice targets for pirates...

IISS x-boat stations and IN bases will have to be in the outsystem too, so if most of your interstellar infrastructure is out there that is where it makes sense for you to build your starport rather than space ports. It could be a completely artificial station or it could be a large asteroid/dwarf planet or the moon of a gas giant...

 

[boomslang]

I guess most (if not all) those worlds have some way of space station or any minor planet facility in the jump limit serving as main spaceport terminal, so that ships do not really rach the planet (unles they really need to) and can just load/unload caroes and passengers.

Once in this terminal, of course, fast shuttles take the cargoes or passengers to the planet.

Of course, this will afect their trade, as you need this extra time for any movement in/out the main planet.

IMTU (at least) these facilities are typically called "farports" and in addition to providing cargo/passenger way stations to/from the system mainworld, are frequently part of a "whistle stop" economic model for the locals that supports shipping moving through the system to other destinations, but which needs a quick local refuel and resupply point. A large, scheduled merchantman or liner can refuel and be back on its way to its endpoint destination much more quickly via a dedicated deep-space servicing facility than it can by crawling down and back up the star's -- or even a small GG's -- gravity well. Several days less that the one week a starship typically spends in port, for sure.

This in turn can save a big ship enough "down" time (i.e., any time in which it is not moving payload through Jumpspace for profit and is only running up overhead) to make the quick stopover economically attractive. In exchange, the local system can get otherwise-unlikely passenger, freight, and even Mail traffic on a regular basis, if they are willing to provide enough infrastructure locally.

 

[tjoneslo]

Once you start introducing the complications of stellar masking and adding Far Ports to deal with them, you might as well take the next step.

GT:Far Trader has a section for dealing with the idea of Jump Masking. It then proposes a solution, if you are willing to accept their large scale shipping.

LASH (Lighter aboard Ship) takes the idea of battle riders and apply them to the commercial shipping industry. Instead of having a far port where you dock, unload cargo, load cargo, then move on you have the cargo (and passengers) loaded on the ship via a non-jump capable lighters.

When the ship arrives in the system, you have a large non-jump capable fuel tanker with a collection of pilots. This catches the incoming ship and refuels the ship. The pilots load themselves into the various lighters which are staying in the system, and take off. The same thing happens with the cargo which is outgoing. Refueling happens in a few hours and the ship moves on.

The long time (week+) taken to fly to a world, load and unload cargo, and so forth is now avoided.

So there is no "far port", just a large, high-g Fuel Tanker, and a whole set of high-g cargo lighters. The cargo ships are mostly empty frames to hold the lighters, and can probably do without a maneuver drive, or at least a minimal one.

Yes, there is some cargo loss because the lighters all have a maneuver drive and power plant. But since the carrier ship can now make 15-20 more jumps per year, this will make up the difference.

 

[kilemall]

Once you start introducing the complications of stellar masking and adding Far Ports to deal with them, you might as well take the next step.

GT:Far Trader has a section for dealing with the idea of Jump Masking. It then proposes a solution, if you are willing to accept their large scale shipping.

LASH (Lighter aboard Ship) takes the idea of battle riders and apply them to the commercial shipping industry. Instead of having a far port where you dock, unload cargo, load cargo, then move on you have the cargo (and passengers) loaded on the ship via a non-jump capable lighters.

When the ship arrives in the system, you have a large non-jump capable fuel tanker with a collection of pilots. This catches the incoming ship and refuels the ship. The pilots load themselves into the various lighters which are staying in the system, and take off. The same thing happens with the cargo which is outgoing. Refueling happens in a few hours and the ship moves on.

The long time (week+) taken to fly to a world, load and unload cargo, and so forth is now avoided.

So there is no "far port", just a large, high-g Fuel Tanker, and a whole set of high-g cargo lighters. The cargo ships are mostly empty frames to hold the lighters, and can probably do without a maneuver drive, or at least a minimal one.

Yes, there is some cargo loss because the lighters all have a maneuver drive and power plant. But since the carrier ship can now make 15-20 more jumps per year, this will make up the difference.

Basically, Heighliners from Dune.