Jump Bubble diameter and location of Jump Drive

Discuss the Traveller RPG and its many settings
Condottiere
Warlord Mongoose
Posts: 8124
Joined: Mon Sep 23, 2013 8:23 pm

Re: Jump Bubble diameter and location of Jump Drive

Postby Condottiere » Mon Dec 16, 2013 10:40 am

Is this dependent on the power plant factor?

You're in the middle of a Jump 4 powered by a factor four fusion plant. It dies, and the secondary power plant factor one kicks in.
Condottiere
Warlord Mongoose
Posts: 8124
Joined: Mon Sep 23, 2013 8:23 pm

Re: Jump Bubble diameter and location of Jump Drive

Postby Condottiere » Wed Feb 12, 2014 4:35 pm

Just thought of some interesting scenarios:

1. This one is more for the pirate thread (whichever that was): just as the freighter is about to jump, direct a stealthed drone into the jump bubble diameter; if it was jump one, the jump bubble should collapse and transition fails.

2. What happens when two nearby starships decide to jump simultaneously, and are close enough that their jump bubbles overlap?

3. What happens when two nearby starships decide to jump simultaneously, and are close enough that their jump bubbles overlap, and in the overlapped area is a large enough mass to be taken into consideration by the astronavigator?
Rikki Tikki Traveller
Cosmic Mongoose
Posts: 3432
Joined: Mon Aug 06, 2007 3:20 pm
Location: Arlington, TX USA

Re: Jump Bubble diameter and location of Jump Drive

Postby Rikki Tikki Traveller » Wed Feb 12, 2014 4:49 pm

Condottiere wrote:Just thought of some interesting scenarios:

1. This one is more for the pirate thread (whichever that was): just as the freighter is about to jump, direct a stealthed drone into the jump bubble diameter; if it was jump one, the jump bubble should collapse and transition fails.

2. What happens when two nearby starships decide to jump simultaneously, and are close enough that their jump bubbles overlap?

3. What happens when two nearby starships decide to jump simultaneously, and are close enough that their jump bubbles overlap, and in the overlapped area is a large enough mass to be taken into consideration by the astronavigator?
As far as I know, none of these scenarios have ever been explained in the official rules, so you can decide for yourself.
My friends call me Richard.
You can call me Sir.
phavoc
Cosmic Mongoose
Posts: 4910
Joined: Tue Nov 04, 2008 6:13 pm

Re: Jump Bubble diameter and location of Jump Drive

Postby phavoc » Wed Feb 12, 2014 4:57 pm

Condottiere wrote:Just thought of some interesting scenarios:

1. This one is more for the pirate thread (whichever that was): just as the freighter is about to jump, direct a stealthed drone into the jump bubble diameter; if it was jump one, the jump bubble should collapse and transition fails.
The rules really don't cover this in that way. Essentially if you are within 100D of an object you have a chance for a mis-jump. But it's based on the mass of the other object and your own, so you'd never see a jump bubble collapse (unless the stealth drone somehow could affect localized gravity fields... then it would be a different discussion).
Condottiere wrote: 2. What happens when two nearby starships decide to jump simultaneously, and are close enough that their jump bubbles overlap?
One, or both ships, would have to roll on the jump mis-hap table. It's no different than trying to jump too close to a planet or asteroid or whatever.
Condottiere wrote: 3. What happens when two nearby starships decide to jump simultaneously, and are close enough that their jump bubbles overlap, and in the overlapped area is a large enough mass to be taken into consideration by the astronavigator?
Should be same as above.
mr31337
Banded Mongoose
Posts: 218
Joined: Wed Apr 06, 2011 12:49 pm
Location: United Kingdom
Contact:

Re: Jump Bubble diameter and location of Jump Drive

Postby mr31337 » Tue Feb 25, 2014 4:57 pm

I've not had time to read all the way through this thread so please excuse me if this has already been posted.
Traveller5 wrote:Jump Bubble
Without any additional mechanisms, the Jump Drive creates a quasi-spherical (often an egg-shaped oblate spheroid) bubble.
The Naval Architect Manual computes the size of the Jump Bubble as
D= (Tons * 13.5 )^1/3 *20 (in meters)

<snip>....For most purposes, a Jump Bubble is about five times
the diameter of the average of Length, Width, and Height of
the ship and centered on the Jump Drive....<snip>
I hope this helps.
User avatar
Reynard
Cosmic Mongoose
Posts: 3496
Joined: Sat Jun 18, 2011 10:03 pm

Re: Jump Bubble diameter and location of Jump Drive

Postby Reynard » Tue Feb 25, 2014 7:47 pm

Remember one thing about the 100D rule. Those are for massive gravitational bodies. The grav plates are highly localized so different parts of a vessel can have separate levels. This means neither the insignificant mass of the ship and contents nor the artificial gravity have a bearing on Jump.

That said, I would have whoever was in charge of the sensors spaced if they didn't know another ship was in proximity during Jump prep. If not an incompetent sensor operator, the system itself should have emergency protocols to detect such mass and field concerns (a Jump will be charging the hull, the energy would be noticeable and the time sequence would be measureable) and automatically warn the operator and even initiate shut down to avoid imminent danger.

A cloaked pirate with stealthed anti-Jump drones should be in the 99.999... range of probability. Even then I'm sure a Jump bubble's displacement limit has a range, however small, that a drone would have to be HUGE to have an affect, say a drone fighter. Gravimetric sensors should detect object with significant mass at range if only to sweep the area for inter-space matter that could disrupt a Jump.

All of this is considered transparent and normal SOP. The Really Weird Stuff is for the scriptwriters (WARNING, THIS IS A PLOT DEVICE!) that is part of the exciting adventure and GONNA HAPPEN because it's in the script and you have to deal with it and win.

Are those pirates some sort of cloaked Romulans?
User avatar
ShawnDriscoll
Cosmic Mongoose
Posts: 2963
Joined: Sun Dec 13, 2009 6:13 pm

Re: Jump Bubble diameter and location of Jump Drive

Postby ShawnDriscoll » Tue Feb 25, 2014 9:22 pm

I think I'll do a video on this topic, showing various bubble types on CG models.
Condottiere
Warlord Mongoose
Posts: 8124
Joined: Mon Sep 23, 2013 8:23 pm

Re: Jump Bubble diameter and location of Jump Drive

Postby Condottiere » Wed Feb 26, 2014 9:02 am

1. Thanks.

2. I still believe that piracy is not a viable economic activity within the borders of the Imperium, but if I had to commit it, or something with a similar outcome, that's what I'd plan to do. IE surprise them when they least expect it and don't let them call for help.
Condottiere
Warlord Mongoose
Posts: 8124
Joined: Mon Sep 23, 2013 8:23 pm

Re: Jump Bubble diameter and location of Jump Drive

Postby Condottiere » Sun Mar 26, 2017 10:39 pm

I suddenly realized, I had forgotten the formula for the diameter of the jump bubble.

Doesn't seem to be included in Mongoose Second, either.
User avatar
NOLATrav
Banded Mongoose
Posts: 316
Joined: Sun Sep 06, 2015 7:42 pm
Location: Crescent City

Re: Jump Bubble diameter and location of Jump Drive

Postby NOLATrav » Mon Mar 27, 2017 2:06 am

Ever since the jump bubble became the new lanthanum grid, I've used the following:

1) Jump drives may be placed anywhere in the ship's hull. A "grid" of "nodes" within the hull, along with jump software, locates the absolute dimensional center of the ship for the j-drive, which is also the absolute center of the spherical jump bubble.

2) The diameter of the jump bubble is equal to the longest physical dimension of the ship, plus 2 meters (one meter on either side of the ship's longest dimension).

3) This means on the shorter axes of the ship's dimensions there could be tens of meters between the hull and the jump bubble. This also means people could move about the hull in jump space but on a typical 100 ton Scout or 200 ton Trader for instance the jump bubble will be very close to the "nose" and "tail" of the ship.

4) Hull damage increases the risk of misjump simply due to possible miscalculations of the ship's dimensional center. Software maybe be able to override it or it may have to be repaired before a safe jump can happen.

5) Looking at the jump bubble can induce disorientation, jump sickness or insanity depending on length of exposure.

6) Contact with the jump bubble is equal to a localized disintegration effect. Disruption of the jump bubble occurs if the object causing the disruption displaces 5% of the hull or more. Disruption of the jump bubble results in immediately dropping out of jump space, a misjump or catastrophic destruction of the ship depending the displacement of the disrupting object.

I built in rules that made it damned hard to survive an EVA during jump, but allow it if it makes for good gaming.

This was inspired by a thread over on COTI where a user described playing a session with his kids and they went out on the hull during jump. One of the PCs hands breached the jump bubble and the Ref ruled it was lost, much like Luke Skywalker's hand at the end of ESB. It sounded like a blast and I thought it was supercool so I built it into MTU. IMHO it should always be about risk and reward for the players. A blanket "They die. Horribly." is paramount to TPK. IMTU the players were in a similar situation but the 100 ton Scout itself breached the jump bubble slightly - they basically lost the aft air/bay and dropped out of jump exactly where the entered, venting atmo with the bad guys still there. It was loads of fun and they limped back to the Scout base they'd just left with a helluva story to tell.

Travellers are supposed to be awesome. They should have the chance to do daring, awesome things and live to tell the tale.

Who is online

Users browsing this forum: No registered users and 24 guests