Jump Drive

[AnotherDilbert]

That is why I separated it into two different rules.

Blockage is at the instant of jump.

Exit at the 100 D limit is at the end of the jump ~168 h later.


I agree it is not consistent, but it seems to be what T5 says. If taken literally it would mean that if the courseline is blocked by e.g. a station, the jumping ship would exit the jump where the station's 100 D limit was 168 h ago, or if that is within the current 100 D limit at the current 100 D limit.

 

[Condottiere]

I doubt it will ever be consistent.

It's primarily how the warp interacts with Einteinianspace; if the astrogator, pilot and engineer do their jobs correctly, the starship is precisely at the point space and pointed in the correct direction, that has been precalculated by the astrogator, and the jump drive syncs perfectly with another dimension, is drawn in and ejected more or less where expected, and time experienced by the crew is about exactly how long they weren't on this plane of existence.

To prevent gaming the system, whether with microjumps or transitus interruptus, the time factor remains the same.

 

[Carlobrand]

Blockage at initiation of jump ... does that mean T5's not doing the 10-diameter/100-diameter misjump roll modifiers anymore?

All debates about mechanics aside, this all sounds more like a plot tool than a game mechanic. This will stop someone from jumping when a larger ship is very close to them - say, about to scoop the Princess' ship into an empty bay. Other than that, it amounts to the gamemaster deciding that the collection of ships a few thousand kilometers away happens to be in position to block your planned escape. There's no calculating a jump to a neighboring system - or the position of other ships - so precisely that a gamemaster knows another ship just happens to be in the way by random chance. It's one of those moments when you slap the switch and the speaker announces, "Warning, this is a plot complication!"

 

[AnotherDilbert]

Blockage at initiation of jump ... does that mean T5's not doing the 10-diameter/100-diameter misjump roll modifiers anymore?

No, not that I can find:

Movement To The Jump Point
The ship moves to the selected point for the initiation of jump. The location at which a ship will enter jump space is a Jump Point. A Jump Point must be at least 100 Diameters from every body (star, planet, gas giant, planetoid, or other object) larger than the ship.

Of course, the "100 D" limit is variable and depending on the jump drive, jump field type, and astrogation skill.

 

[Condottiere]

Starships: Engineering, Jump Bubble, and The Torus & Toroidal Flow extract from Thrive 2011 documentary.avi

This is an extract from the documentary Thrive 2011 describing 'THE TORUS' and 'TOROIDAL FLOW....... Everybody watch and understand the significance of this Inc. free unlimited energy. all future technology for space travel including interstellar.

i include a link for the spherical arrangement of the ICHING symbols that i have used to theorize that the great 2012 experience is as we approach the singularity at the Toroidal center which in compasses our known universe. we are currently traveling through the vortex of The Torus, first link is a high resolution representation of the ICHING Hexagrams clearly arranged within a sphere in a Toroidal flow

https://www.youtube.com/watch?v=5i2NlruQec0

Consider this the highlights; I was doing data recovery on one of my video libraries and came across the original.

It sort of fits in if you consider the jump drive radiates out from a central point.

 

[whartung]

Because the stars aren't obriting the galaxy at the same speed, your target system is moving relative to your system on the order of 10s of km/sec. Over the course of a week long jump, that is some multiple of 6M km - far more than the 100D limit of a planet we can roll up. So now you have a situation where you could jump in as close to a planet as your accuracy because the 100D limit won't be anywhere near that target when you initiated.

This an interesting ramification.

Consider this contrived case.

The planet to which the ship is jumping, Just So Happens to be directly in front of the ship, even though the ship is parsecs away. Also, the combination of the star system and planet orbit Just So Happens to give the vector of the planet relative to the ship to be moving directly away from the ship. Simply, if the ship is "standing still", the planet moves away.

This means that if the ship wanted to arrive as close to the planet as possible, the navigator will want to take in to account the velocity of the planet and plot where the planet will be in one week.

At which point, the ship jumps.

Now.

If were using the "yank ships out of jump" rules which happens AT THE START of Jump, then while the ship will arrive in the correct system, at the correct time, the ships position will be based on where the planet was at the START of Jump, not end of Jump. Because the planet is "in the way" of the planned destination, which is the planets position one week from now.

Now, if were using the "100D when leaving Jump" rule, then the ship will arrive closer to the planet. The beauty of this 100D rule is that the actual timing of the arrival is less vital, since the planet will force precipitation at 100D no matter what, the 10% window is less dangerous. "Oops, I arrived late and smacked in to the planet" (which no navigator would plot for, but...anyway).

So, it's an interesting little twist on routine operations. "Due to the planets orbit we're going to be arriving a little late and spend more time docking than normal."

I'm of the "plot to arrive in front of the planet ilk" so as to strive to always arrive at the 100D barrier of the planet, with my vector going headlong in to the planets path to shorten arrival time by any amount possible.

 

[Condottiere]

One would presume that precipitous precipitation can damage ship systems, like engineering, the bridge and/or hull.

 

[AnotherDilbert]

So, it's an interesting little twist on routine operations. "Due to the planets orbit we're going to be arriving a little late and spend more time docking than normal."

We have two conditions in T5:

Blockage at the start of the jump.

Can't exit jump within 100 D at the end of the jump.


So, you aim for the position of the target planet at the end of the jump, and if you hit, you exit at the 100 D limit current at the end of the jump. If anything blocks the course-line at the start of the jump, the jump might end longer from the target.

 

[whartung]

So, you aim for the position of the target planet at the end of the jump, and if you hit, you exit at the 100 D limit current at the end of the jump. If anything blocks the course-line at the start of the jump, the jump might end longer from the target.

That was my entire point. The planet blocks at the start of the Jump, so when you arrive, the planet will be "a week" of planet velocity away, vs being 100D from the planet where it currently resides.

 

[BackworldTraveller]

The thing about engineering solutions is that you aren't finished until you can't take anything else away. Occam had the right idea. With the Jump process for Traveller, it seems that the originally simple process has had stuff added and added and is thus getting harder and harder to justify

 

[coliver988]

The thing about engineering solutions is that you aren't finished until you can't take anything else away. Occam had the right idea. With the Jump process for Traveller, it seems that the originally simple process has had stuff added and added and is thus getting harder and harder to justify

Pretty much this, in the same way that Star Wars got ruined for me when they introduced the mitochlorians or whatever to "explain" the force (ignoring all the other "fixes" added after the fact). Some things are better just left vague and "it just works". Unless your specific game needs all those mechanics and checks. I just go with the astrogator makes a roll to see how close they end up to 100D, and the engineer makes a roll to make sure nothing bad happens to the jump drives, and the pilot makes the roll to coordinate it all. And that's if there are PCs in those positions: if not, unless the plot needs it for whatever reason, the jump just works and they spend their week in jump and come out about where they need to.

Unless they are using unrefined fuel and don't have fuel filters...then there is always a roll for misjump per RAW.

But: I am enjoying this thread and it brought up things that *may* get added to my game table. Where there is a game table to get back to! Thanks for all the constructive comments, and keep it coming!

 

[AnotherDilbert]

That was my entire point. The planet blocks at the start of the Jump, so when you arrive, the planet will be "a week" of planet velocity away, vs being 100D from the planet where it currently resides.

That is only a problem if the planet moves directly away from the jump origin.

Solved by aiming a little to the side of the planet, about 100 D out from where the planet will be at the end of jump.


If the planet moves sideways, or at an angle from the course-line, the position of the planet at the start of the jump will not block the course-line to the position of the planet at the end of the jump.

 

[mike wightman]

You have a database with the current position of every charted object within your jump range.

Current as in a god mode view of them.

What you see through your sensors is out of date since you are looking at information from the past.

You aim your jump line for where you want to arrive in 1 week's time - as close to the 100D limit of the target world's location in one week since you can predict exactly where it is going to be thanks to general relativity calculations.

At the instant you press the jump button your target planet is unlikely to be anywhere near blocking the jump line since it is still one week of planetary, stellar, and galactic movement away from the location you have aimed to arrived at.

Which brings up the real issue of making this stuff so complicated.

If the jump line is a god mode straight line then you have to consider the real movement of planets, stars and the galaxy relative to this straight line.

Here is a video if what the movement of a planet and system would look like to an outside observer:
https://www.youtube.com/watch?v=rQJDEhlE-DY
or -
https://www.youtube.com/watch?v=oHcaN586VbM

 

[Straybow]

oHcaN586VbM says "video not available"

 

[Straybow]

It appears that jump space is a plane, and I'm not familiar with Sol subsector's systems, so I don't know how they lie with respect to Sol's equatorial plane. It would be rather convenient, however, if we could assume that the odds a particular system's equatorial plane lay parallel to the jump plane were low.

While canon says that jump space is a "plane" it's clearly not a Euclidean geometry of infinitesimal thickness. It is only a "plane" in the sense of abstract mapping. Otherwise you'd have to map the intersecting angle of jump space plane on each system, which would control jump entry and exit locations.


And even that in-game explanation falls flat. har har