Pseudo-science (OR a question about jump drive physics)

[FallingPhoenix]

I recently had my PCs escape from a hostile space station with a ship with almost no fuel by docking it with a ship with an overlarge jump drive that was full of fuel and using the one jump drive to jump both of them.

Not unreasonable...

The question this brought up however, was this:

What happens if you activate a jump drive while already in jump?

FP, either breaking the Jump 6 limit or disappearing into the vastness of interstellar space...

 

[alex_greene]

I suspect that the phrase "emerging from a Jump as a burst of undifferentiated photons" springs to mind.

 

[iainjcoleman]

You can't break the J-6 limit this way, because if you could then everyone would be doing it and it wouldn't be a limit any more.

The "burst of photons" idea is reasonable, but perhaps a little pedestrian.

I would suggest that ships that do this simply vanish, never to be heard from again. Some say they are destroyed, some say they jump through intergalactic distances, some say they travel through vast stretches of time, some say they jump into another universe altogether. From time to time an individual or a small religious cult deliberately jumps-in-jump, believing that they will be carried off to some distant space, time or reality. Imperial scientists largely concur that the ship would simply be destroyed, but have not so far been able to develop a consistent theoretical solution for the problem, and a minority of scientists speculate that some exotic form of travel may be possible when a ship jumps-in-jump.

So, if your players are ever foolish enough to do this, I would suggest rolling up a random subsector to reboot your campaign - or bringing out the Hammers Slammers, Babylon 5 or Judge Dredd sourcebooks.

 

[Madarin Dude]

I would count it as a forced misjump. You then determine the hex they tried it in and roll a D6 for direction and a D6 for how many D6 you roll in that direction. If they end up in open space they are toast. If you want to be mean you can put them quite a ways out if they come into a system so it takes weeks to get in.

 

[Mongoose Gar]

I'd second the 'as far as the Imperium knows, it's suicide, but if the players try it, they end up in a galaxy far far away'.

That, or they tear a hole in the jump bubble, and things come through. The players now have to survive the rest of the jump with Cthulhu's first cousin munching on their hull.

 

[Stofsk]

What happens if you activate a jump drive while already in jump?

Can you activate a jump drive while already in jump?

To jump, the drive has to spend a lot of fuel to create a jump field, which is what propels a ship into jump space and keeps it there for the journey. Wouldn't that imply that the jump drive is actually 'active' whilst in jump, to maintain the field? Isn't that said somewhere in fluff material about how the jump drive supposedly works?

I remember T20's design sequence said something like "Jump drives need x amount of Energy Points per drive unit whilst active". I don't know if there is anything comparable in MGT, I just looked at the engineering section of the pocket rulebook and it doesn't say anything like what I paraphrased. But at the same time, it did say that the jump drive rating determines what power plant is needed. Which would seem to imply that the drive needs to be powered by the power plant, although not necessarily all the time.

I would personally just go "You can't activate a jump drive while in transit, because its already 'active'." I suppose you could have a back up jump drive installed, but to activate it wouldn't you also need fuel? Typically, Traveller ships carry only enough fuel for x1 jump. So design a prototype ship which has two jump drives, and enough fuel for two jumps, and then try to activate the second drive while the first one has been used. I like the 'undifferentiated photons' result.

Maybe this should be filed under You Could But Why Would You Want To?

 

[alex_greene]

What happens if you activate a jump drive while already in jump?

Can you activate a jump drive while already in jump?

To jump, the drive has to spend a lot of fuel to create a jump field, which is what propels a ship into jump space and keeps it there for the journey. Wouldn't that imply that the jump drive is actually 'active' whilst in jump, to maintain the field? Isn't that said somewhere in fluff material about how the jump drive supposedly works?

The theory is this.

Jump ship A carriues Jump Ship B. Jump Ship A activates its Jump drive whilst B's drive in inert.

Jump Ship B is fully fuelled.

During Jump, Jump Ship B spins up its own Jump drive.

Hence the question: How big a cockup does this cause, and what part of the EM spectrum will the player characters occupy when their component photons energe from the Jump envelope?

 

[Stofsk]

Argh that's what I get for not reading the OP carefully.

I think that as the carrying ship is already powering an active jump field, anything that disturbs that will likely result in a Everybody Dies scenario. IIRC anything that upsets or disrupts the jump field whilst active ends in certain catastrophe. Traveller Wiki article on jump drives:

The Jump Drive opens a transition to jumpspace. Every ship stays in jump for around one week before entering normal space again. Ships in jump are isolated, and can not detect or communicate anything; they are totally isolated in a small bubble of space until they reemerge into out universe again. Even if two ships side by side (far enough apart to avoid field interference) jump at the same instant, they are totally alone. Cases of field overlap (interference) have been known to result in direction error, range error, system damage, or ship destruction, and is advised against.

Emphasis mine. Both ships are docked together and are in jump together, which right there might even mean a risk of misjump. (Starships aren't supposed to piggy back other ships, unless you're talking about Tenders which are designed for it.)

I guess if you power up a drive in the scenario as described by the OP, whilst in jump, the end result would be catastrophe.

 

[AdrianH]

To paraphrase:
"Have you ever wondered what happens if you jump while in jump space?"
"No! And neither should you!"

I agree with Mongoose Gar 100%. Effectively it's suicide - either the jump drive implodes or you end up returning to normal space somewhere - roll 1D6, multiply by your choice of power of 10, that's how many light years away they end up. Then roll up new characters.

For more amusement, if you regard jump space as one level above normal space, jumping from within jump space takes you one level further. Call it third space. One week later you return somewhere in jump space; another week later you're back in normal space. Fortunately, you're actually back somewhere you recognise. This is because someone in third space has seen you and wants you to get home for some reason... If you're lucky, the aliens are friendly. If you're not, say hello to Cthulhu. :twisted:

 

[RandyT0001]

IMTU if jump drive A is already on creating a jump buble that is interacting with jumps space and the ship is in jump space then jump drive B just basically will not work. As the crew tries to turn it on it's jump drive B bubble collapses unable to establish contact/interaction with the jump space - normal space barrier created by jump drive A. If the crew is really determined to try they must make a couple of impossible task rolls and if they actually succeed then they recieve a high burst of gamma radiation poison as the energy is reflected off the first jump drive A bubble, causing a misjump to occur (roll 1d6 for direction and 3d6 for range). So upon exiting jump space they will have misjumped and are suffering serious radiation poisoning. The computer probably got fried also so the wont be able to steer the ship upon re-entering normal space. Hopefully a local patrol ship will spot them and be able to rescue the crew and passengers before dying from radiation poisoning. If they do get the medical treatment they will still have to replace both jump drives since their stunt has effectively destroyed them.

 

[Strangelove]

I recently had my PCs escape from a hostile space station with a ship with almost no fuel by docking it with a ship with an overlarge jump drive that was full of fuel and using the one jump drive to jump both of them.

Not unreasonable...

The question this brought up however, was this:

What happens if you activate a jump drive while already in jump?

FP, either breaking the Jump 6 limit or disappearing into the vastness of interstellar space...

How would you be able to plot an astrogation course inside jumpspace without any external references? The computers controlling the jump drive require coordinates to know how to shape, or in my case point, the jump field to ensure you arrive at the desired destination.

The following is MY rationalization so use with caution:

I always looked at it using the trusty "right hand rule" used in so many engineering disciplines. I imagine the jump bubble as spinning on an axis, if you curl your four fingers around the axis in the spin direction of the jump bubble surface then point your thumb outwards it shows the direction of the destination. The velocity of the surface determines the distance to be jumped, with longer jumps requiring a significantly higher velocity to the ship at rest inside. This magnitude and direction gives the situation a vector which is fundamental to any engineering dynamics solution. Think of it like this graphic of electric current where B is the spin of the bubble and I is the line of action (your thumb from above analogy).

I further use this spin of the jump bubble surface just prior to leaving "normal space" to be noticeable due to how it temporarily distorts space-time around itself causing lensing similar to distant stars which makes it detectable.

I describe the internal working of the jump drive navigation as being a gyroscope that when coupled to the actual jump powerplant has its spin magnitude multiplied in a fashion similar to the way torque is a force times a distance. This spin up provides a nice auditory sensation inside the ship and the inertia of the gyroscope makes maneuvering the ship while trying to jump near impossible since by their very nature gyroscopes self stabilize.

The description of the drive "spooling" up to speed satisfies my need for drama while being backed with a quantitative mechanic that you could, if desired actually put numbers to. Such as so many rpms divided by the displacement of the hull times the power of the jumpdrive equals the displacement in parsecs. What can I say, I like things having formulas.

So once in jumpspace you can spin the drive but the direction of the gyroscope axis no longer orients to a point in realspace and your ship no longer exists at an X,Y,Z point of origin in realspace. Hence, all show and no go.

 

[kristof65]

I would handle it with one of the following results - I'd probably determine it randomly:

1) Nothing happens
2) The ship is immediately expelled from J-space, and a lot of damage occurs.
3) The ship misjumps so far away, the PCs have absolutely no idea where they are, and they will never see human space again.
4) The ship gets to its destination, but it's in an alternate universe. They might even run into bearded versions of themselves
5) The ship gets to its destination, but its not their time period.
6) If I was feeling particularly Star Trekish, the resulting field distortions cause a copy of the ship(s), crew and passenger(s) to come into being. The second copies will not show up out of jump space until a few hours/days after the original does. Those copies will be stripped of all moral convictions, and will get the PCs into a lot of trouble.

 

[iainjcoleman]

6) If I was feeling particularly Star Trekish, the resulting field distortions cause a copy of the ship(s), crew and passenger(s) to come into being. The second copies will not show up out of jump space until a few hours/days after the original does. Those copies will be stripped of all moral convictions, and will get the PCs into a lot of trouble.

I would be wary of assuming the PCs had any moral convictions to begin with.

 

[BP]

Not a real fan of the Jump Travel 'details'... I describe Jump drives as an 'engine' that moves the ship upto x parsecs. Details? - via Jump Field and Jump Space. I.E. all aspects other than distance and time are purely fictional. RW cannot break it on any level other than the whole concept (so I only have to really suspend disbelief of one concept outside my experience and human knowledge).

Using the 'hydrogen bubble', parallel universe theory, well...

If I were to try and stretch it I'd say that Jumping from a Jump 'bubble' 'parallel universe' just adds another 'bubble' and 'parallel universe' that collapses into the original one and back to real space when the original one does. I.E. Jumping withing Jump proves nothing because one still ends up returning to real space at the same time in the same basic space as the original jump (although the internal/attached starship would 'disappear' into its own parallel universe during the jump).

Or, you are cosmic dust - since you can't move any real distance other than within the original jump bubble - otherwise you jump outside the original bubble (and outside any universe).

Now, let's talk about using one's maneuver drive within that hydrogen bubble...

(Argh...)

 

[Lord High Munchkin]

What about safety overrides to stop the players doing such craziness?

If they override the safety - arm the ship's self destruct. They should soon get the message. If not, well they were warned!

 

[AndrewW]

Emphasis mine. Both ships are docked together and are in jump together, which right there might even mean a risk of misjump. (Starships aren't supposed to piggy back other ships, unless you're talking about Tenders which are designed for it.)

Well, any ship with docking clamps would be. Scoundrel makes mention of ships docked together using the airlock and jumping.

 

[captainjack23]

One. Point out that no ship has ever returned from attmpting to activate jumpdrives while in jumpspace. Period. We don't know why, we do know that they never come back. All claims otherwise have been proven to be frauds.

Then if the players do try it, as occasionally happens with daredevils and crackpot researchers (big foofara with local press: "Dr Iapetus Smith to examine new double jump effect".....never heard from again), one is perfectly justified with either rerolling all PC's or, if one has the time and desire, dumping them in a pocket universe with, say, a bunch of dead hulks from other attempts or into D&D world (complete with Dragons and Dungeons....and crystal spheres and ether), or perhaps into wonderland with the cheshire cat and all....and take it from there. Perhaps they will be the first to return - but with no proof, and such an absurd story, they are obviously another another self evident fraud.... :twisted:


Alternately, It Doesn't Work. A jump drive is simply a machine to open a gap in normal space; outside of normal space, you burn lots of hydrogen, generate lots of power....and nothing happens. (perhaps the power buildup explains why ships don;t return .....gotta go somewhere....)

 

[hdan]

Another idea is this - all J2+ engines already DO multiple jumps, which is why they're higher technology. Each additional J-rating corresponds to a deeper level of jump, with Imperial technology currently being limited to J-6.

The advantage that J2+ drives have is that they contain sufficient technology to control the ship's trajectory during the multi-jump effect and to "stutter-fire" the engine to boost you "up" into the appropriate J-space. The extra jumps all go off almost simultaneously, but a seasoned spacer can tell what J-rating is being attempted.

Likewise, the extra computer program space required - you're not just jumping farther, you're jumping through many levels of j-space, and that is hard to compute.

A J-1 capable ship's crew would be foolish to try stutter-firing its drive to get a J-2, but you could allow it with suitable mis-jump DM's if enough fuel could be carried somehow.

 

[Klaus Kipling]

Emphasis mine. Both ships are docked together and are in jump together, which right there might even mean a risk of misjump. (Starships aren't supposed to piggy back other ships, unless you're talking about Tenders which are designed for it.)

Well, any ship with docking clamps would be. Scoundrel makes mention of ships docked together using the airlock and jumping.

Be a good plot for a game. Salvage vessel finds a drifting ship, latches on to take it home, jumps. The guy/gal they found in the emergency low berth on the stricken craft wakes up and does craaaazy - goes over to the salvaged craft and tries to set of its jump drive.....

.... or maybe he/she is possessed by some disembodied oogiboogi that can switch host. Not original (maybe 10-20% of all Trek plots), but fun...

 

[Sevya]

Being one of the PC's in question, I have put some thought into this since our play session last week. Here's what I've come up with:

1) Unless our docking procedures included a way for the lanthium grids of the two ship to link up, we shouldn't have been able to jump. In CT there was a ship called a "Jump Ship", basically an interstellar tug boat. In order to use its sizable jump drive with cargo, said cargo had to be in cargo pods with a lanthium grid tied in to the ship's drive, or had to be in a lanthium cargo net, also tied into the drive.

2) As for the "Two stage" jump, the best scenario one could hope for is not having any way to navigate the second jump, as was mentioned above. Even if it could work, no-one has tried it because there is no safe way to test it. Worst case scenario, and probably most likely, is that the second ship's jump drive disrupts the firsts, destroying both ships and all on board die. Horribly.

Just what I came up with...

Sevya