How many Jump Points exist in a system?

[mightymozenrath]

I've spent the last several days reading all through nearly every post on Jump space. I cannot find any answers on this.


So, how many Jump points are there in a star system? Most of the literature on in the various manuals give a message of only really one Jump Point in a system.

Comments like, "pirates love to wait in hiding near THE JUMP POINT to ambush ships needing to refuel from a gas giant." And, "many systems have system defense boats and customs ships waiting at THE JUMP POINT to control access to the system."

Please confine your responses to actually answering this question, rather than the usual opinions and wandering off the subject of "well in my campaign..." Also, I am not a techie guy, so giving me all the mathematical calculations of where Jump Points can exist will just be Greek to me. I don't understand Greek either.


Thank you,

Mozenrath

 

[far-trader]

Hunh, I don't recall the term that way. Classically there is no single or even a numbered set of jump points, only a limit on safe jump distances from large bodies.

As long as you are more than 100d (diameters) from any large body you may safely jump out. And a jump into a system can be made to anywhere that is outside the 100d limit of any large body.

In some cases the 100d limit of one body (for example our sun) may extend far enough to include the 100d limit of other bodies (for example mercury and venus). In those cases you have to use the largest diameter.

In the case of pirates hiding near the jump point, it refers to watching anywhere at the 100d limit of the gas giant for incoming ships that will be low on fuel having expended it jumping in.

In the case of SDBs and customs ships, they are waiting at the 100d limit of the system's worlds, at least the important ones, which is where incoming ships will arrive.

So it's not really a point or points as much as it is several large spherical surfaces and anywhere beyond them.

Hope that clears it up

 

[far-trader]

Found it! There is a table of 100d limits here to save you any math:

http://www.travellerrpg.com/CotI/Discuss/showthread.php?t=19177

 

[Blix]

While the jump distance may be defined by a 100D sphere around a star, each neighboring star system is in a specific direction in space from the current system, and jump seems to work in a straight line between the two systems. So I think it would follow that incoming traffic should be focussed where a line in space drawn in space from the departure system intersects with a 100D limit in the arrival system.

Outgoing traffic could potentially leave from any point on or beyond that half of the 100D sphere that faces the destination system though (it cannot leave from the other half since the jump shadow of the star would block the jump route).

 

[aramis]

Certain 3rd party authors presumed there were limited numbers of jump points.

Certain editions made conditions where jump entry/exit points are predictable.

TNE, due to reaction thrusters only, implies strongly that there is an optimal course plot, and that one's jump course will be plotted so as to minimize your braking thrust to orbit. This means a very narrow window of jump exit locations for incoming traffic, due to relative stellar motions, etc.

No Traveller edition has ever said there is a specific required point for jump-out. Any point beyond the 100 diameter limit is a safe jump, inside a dangerous jump.

Only GTIW has required a limited set of jump-in points, and that merely any spot facing the jump-in point along the 100 diameter shell.

 

[far-trader]

Reading Wil's notes above it occurs to me, there could well be defined Jump Points in Traveller. They'd be accepted, regulated, legal entry and exit points and any traffic outside those areas would be considered suspicious. You could still jump in or out and ignore the Jump Points, but it'd be at the risk of being mistaken for pirates, raiders, or the enemy.

Not a new idea, just thought I'd note the possibility.

Was that the GTIW take on it?

 

[Zparkz]

far-trader, i agree with you that this seems very likely as it would be easy to patrol this area of space. The benefit would be that merchants would expect to find this space patrolled and safe from pirates. Exiting any place else have the advantage of your entry may be covert and unoticed. But on the other hand, the insurance company may take a dim view and hold back on you if you got into trouble and got shot up.

 

[HG_B]

But on the other hand, the insurance company may take a dim view and hold back on you if you got into trouble and got shot up.

Naw, just claim jump error. Nailing an exact entry point at destination system isn't a certainty...

 

[Zparkz]

Naw, just claim jump error. Nailing an exact entry point at destination system isn't a certainty...

Yeah, but a inquiry would likely mean that the flight recorder and log would be inspected. If they are as SOpM claims, they are hard to tamper with.

 

[HG_B]

Yeah, but a inquiry would likely mean that the flight recorder and log would be inspected. If they are as SOpM claims, they are hard to tamper with.

Right. The flight recorder records where you fly. Not necessarily every button pushed by the engineer & navigator... Also, it is the transponder that is sealed, in Trav anyway.

 

[aramis]

Was that the GTIW take on it?

Whilst I only know of it 2nd hand, GTIW requires you must hit a 100D limit to exit jump, and are dropped out always, every time, at a 100D limit.

This has a multiple effect:
1) it makes stellar 100D radii more interesting
2) it reduces all traffic from a specifc system to a hemisphere of exit points or less (depending upon other bodies)
3) it prevents deep space jumps (unless and until a sufficiently large body is detected and charted)

 

[aramis]

Right. The flight recorder records where you fly. Not necessarily every button pushed by the engineer & navigator... Also, it is the transponder that is sealed, in Trav anyway.

SSOM also has the flight data recorder (FDR) as well, sealed. It was the Transponder that was an enslaved natural ai.... and which would scream bloody murder if tampered with... and in the same sealed box as the FDR. (SSOM, p.17)

 

[HG_B]

SSOM also has the flight data recorder (FDR) as well, sealed. It was the Transponder that was an enslaved natural ai.... and which would scream bloody murder if tampered with... and in the same sealed box as the FDR. (SSOM, p.17)

Sorry, I don't know what SSOM is in D20.

 

[far-trader]

SSOM = SOM (aka Starship Operators Manual*) I presume. I think I've seen Wil use that before for it. And I expect you were anticipating a T20 article so you were probably thrown by the MT reference

Or I could be wrong

* Vol 1 actually, though since it was the only one published SOM is usually enough

 

[HG_B]

SSOM = SOM (aka Starship Operators Manual*) I presume. I think I've seen Wil use that before for it. And I expect you were anticipating a T20 article so you were probably thrown by the MT reference

Or I could be wrong

* Vol 1 actually, though since it was the only one published SOM is usually enough

Thanks. Yes, I was thrown as this is the D20 forum so the rule set is assumed for rule questions. Also, the Vol 1 ref always gets me as they never came out with Vol 2, thereby making the "1" appellation redundant although, technically correct.

Thanks.

 

[HG_B]

So I think it would follow that incoming traffic should be focussed where a line in space drawn in space from the departure system intersects with a 100D limit in the arrival system.

Basically, a 100D hemisphere. I think that works out to ~10,618,583,169,133 Km2 of space to cover if you were talking about Earth.

 

[Burocrate]

While the jump distance may be defined by a 100D sphere around a star, each neighboring star system is in a specific direction in space from the current system, and jump seems to work in a straight line between the two systems. So I think it would follow that incoming traffic should be focussed where a line in space drawn in space from the departure system intersects with a 100D limit in the arrival system.

If you want to persue this level of percision you may want to consider that starsystems are not actually stationary in relation to each other. This arguement is often brought up in discussions of 'Jump Tapes', 'Jump Masking' and 'Jump Shadows'. I would recommend a search this site for "Jump" and looking at what is available on other sites like Freelance Traveller.

Hope this helps you define Jump IYTU.

 

[shadowcat20]

It seems to me Pirates might hang around the 95 Dia area. They can hit their targets with them haveing no chance of getting away by jump. Also they would be close the the magic 100 mark in case they needed to split. This would also greatly reduce the area needed to watch for targets. Same with SDB's and police. Maybe hang at the 80 Dia mark so their suspects can not jump out before they are caught and disabled. At that point it is also apperent where they are going so no chance to claim the contraband cargo was never intended to be landed on that planet. I suspect the 100 Dia mark is also considered how far out the planets influence goes for law and police protection.

Just my 2 credits

 

[mightymozenrath]

Thanks...

Thank you to all who posted an answer, especially Dan Burns.

You gave me the info I am looking for... Dan, I just want to thank you personally as you have always responded with useful info and provide what I am looking for. I don't post on here often, but this was the first time I actually got lots of useful feedback.

-Mozenrath

 

[far-trader]

Thank you to all who posted an answer, especially Dan Burns.

You gave me the info I am looking for...

I did what now?! How'd that happen? Guess I get lucky sometimes. I hang out here too much so I get to be first reply a lot and if I pound on the keys long enough something has to be right...



You're more than welcome Mozenrath. Glad to have helped