Electric jump drive.

[Condottiere]

I think that jump capacitors act as spark plugs.

 

[AnotherDilbert]

My personal interpretation is that although a fusion power plant can deliver the necessary power OUTPUT needed for the jump drive to "do its thing" successfully, the actual "yield" of a fusion power plant in this "wasteful overdrive" condition is basically DIRTY POWER, as opposed to CLEAN POWER.

We all have our own ideas, in the absence of canon. I consider it a buffer to handle the temporary slight difference of the torrent of power from the power plant, and the massive power consumption of the jump drive.

 

[spank]

That was one possibility I had considered,
But there are a few wrinkles.
The fuel cost is extremely front loaded.
IIiRC 80 prevent of jump fuel is spent entering jump space. For a far trader that would be fuel roughly equivalent to a rocket launch.

I think that jump capacitors act as spark plugs.

 

[Condottiere]

That would depend a great deal on what we think each part of the jump drive is supposed to do, and the mechanics of jumping.

I'm going to speculate that for Classic, the fuel powers a generator within the jump drive, that creates energy that manipulates space to punch a hole into another dimension, and that generator needs continuous power from the fusion reactor to power a field that lets the starship remain within that dimension for a week.

 

[spank]

Alot of it does depend on edition,. For example Mongoose Traveller days that a miniature black hole is produced, then ejected into another dimension, creating a bubble which is then inflated with hydrogen.
I prefer the more common explainations where fuel is burned, the capacitors are charged, and then a jump is made. The only wrinkle comes in when you consider the rules for capacitors in High Guard.
I can buy that the capacitors store energy necessary to kick off the jump reaction. However, The problem then becomes what is the limitation on charging the capacitors. Can I run a larger reactor and jump faster? The rules in High Guard only allow faster jumps when jumping at lower numbers than the drive is rated for.
I would prefer a system where a jump take a defined amount of EP, per minute/turn/hour. Ideally it would be something like, 1) capacitors are charged to a certain amount, 2) jump is initiated, and the ship must maintain a certain level of EP input.
I could also buy that the hydrogen is being used, not to make EP, but to generate exotic "jump particles". But that would seem to prelclude fusion and antimatter powered jump drives.

 

[Condottiere]

I think the jump drive is the bottleneck, it can only digest so much energy.

On the other hand, it could be jump physics is the bottleneck, since capacitors can store a great deal more energy, if only in the sense that you could have a factor/six jump drive, charge it to a factor six jump, but designate a one parsec distance, and you'd still take a week to exit.

As regards fuel consumption, outside of collectors, so far it's more a question of efficiency, rather than outright reduction.

 

[mike wightman]

Alot of it does depend on edition,. For example Mongoose Traveller days that a miniature black hole is produced, then ejected into another dimension, creating a bubble which is then inflated with hydrogen.

Really? Where does it say this? Can you remember the reference?

 

[whulorigan]

That would depend a great deal on what we think each part of the jump drive is supposed to do, and the mechanics of jumping.

I'm going to speculate that for Classic, the fuel powers a generator within the jump drive, that creates energy that manipulates space to punch a hole into another dimension, and that generator needs continuous power from the fusion reactor to power a field that lets the starship remain within that dimension for a week.

This is my general "overview" interpretation as well, although I think the major fuel consumption comes from that "creation" of the "jump-bridge" in the first place. Once jumpspace is entered, the energy consumption is more modest in order to maintain a "normal-space" field around the ship while in jumpspace.

I also can accept the additional dual use of L-Hyd as coolant for the Drive while in High-Performance mode operation noted in some interpretations as well (hence why there is also a mention of a "bloom" on sensors prior to a ship engaging jump, due to both superheated waste hydrogen and helium being vented from the ship during Jump Cycle operation).

What I don't buy is the hydrogen "bubble" idea that has popped up in more recent years that hydrogen plasma/gas is somehow used to create a bubble-barrier around the ship between jumpspace and the ship hull. The "Jump-bubble" (so-called) is not a balloon. Hydrogen is matter-particles in the same way that the ship is composed of matter-particles. Any weird-physics that jumpspace can do to the matter of the ship and crew it can do to hydrogen/protons/quarks and electrons in the "plasma/gas-bubble" as well. Venting hydrogen around the ship (even presuming that you can somehow keep it from dissipating away into free-jumpspace) will do nothing helpful.

 

[mike wightman]

The jump bubble containing hydrogen was a T4 misunderstanding of a MT statement.
MgT 1e then used it but I think it has been expunged from 2e.

 

[McPerth]

The rules in High Guard only allow faster jumps when jumping at lower numbers than the drive is rated for.

I don't understand them this way. You cna jump in a single turn if your PP performance is double your jump one, ergardless of using maximum capability or not...

So a J6 ship could jump in a single turn as long as he can devote PP12 to it, but, unless it has PP13+ it can use no power for anything else

 

[whartung]

Alot of it does depend on edition,. For example Mongoose Traveller days that a miniature black hole is produced, then ejected into another dimension, creating a bubble which is then inflated with hydrogen.

Oh boy, that's a "Thrice Upon a Time" disaster waiting to happen.

 

[whulorigan]

Alot of it does depend on edition,. For example Mongoose Traveller days that a miniature black hole is produced, then ejected into another dimension, creating a bubble which is then inflated with hydrogen.

Really? Where does it say this? Can you remember the reference?

The references I found in MgT2 (Update 2022), scattered across p.157-158 say this:

To jump, a ship creates a bubble of hyperspace by means of injecting high-energy exotic particles into an artificial singularity. The singularity is driven out of our universe, creating a tiny parallel universe that is then blown up like a balloon by injecting hydrogen into it. The jump bubble is folded around the ship, carrying it into the little pocket universe. This new universe is short-lived and will eventually collapse, precipitating the ship back into normal space several light-years from its original position.

. . .

While in jumpspace, the ship is completely and utterly cut off from the universe. It hangs in a shimmering bubble of boiling hydrogen, a pocket dimension from which nothing can escape. It cannot communicate with the normal universe, not even by psionic means. It is utterly alone.

. . .

Many misjumps are lethal, causing the jump bubble to collapse early or for time in the bubble to flow differently, so that trillions of subjective years pass inside the bubble and all that comes out the other end is hard radiation caused by protons exceeding their half-life.

(Note that the text-fluff in this final statement is not supported by a particular game-mechanic result in the actual rules, which would seem to imply that the extremity of the statement as stated here is not nearly as common as the text seems to suggest).​

 

[mike wightman]

So it creates a bubble of hyperspace.
And an artificial singularity.
And exotic particles.
And a parallel universe.

What a completed departure from existing OTU canon and MWM's article on jump drive and what we are told in T5.

 

[Condottiere]

I donno.

Jump bubblification simplifies the process, and gives an out for hydrogen byproducts, which did appear to end up in a black hole, before.

 

[mike wightman]

The byproducts are vented into space - coolant is added (part of the jump fuel is used as coolant)

Let's see what Marc says:

Theoretically, jump spaces are alternate universes, each only dimly understood from the standpoint of our own universe. Within jump space, different physical laws apply, making energy costs for reactions and activity different and imposing a different scale on size and distance...

A jump is defined as the movement of matter from one point in space (called normal space) to another point in normal space by travelling through an alternate space (called jump space)...

Starship hulls contain as an integral part of their structure a network of wiring which maintains the jump field around the ship. Without this field, the natural physics of jump space would intrude into the ship’s interior and the alien physical principles would make life impossible, operation of equipment unpredictable, and even the passage of time would be altered. Breaks in the protective network within a starship’s hull are a primary cause of the loss of ships when jumping...

When the jump drive is activated, a large store of fuel is fed through the ship’s power plant to create the energy necessary for the jump drive. In the interests of rapid energy generation, the power plant does not work at full efficiency, and some of the fuel is lost in carrying off fusion byproducts, and in cooling the system. At the end of a very brief period (less than a few minutes), the jump drive capacitors have been charged to capacity. Under computer control, the energy is then fed into appropriate sections of the jump drive and jump begins.

The drive’s first function is to tear a hole in the fabric of space. The hole is precisely created and the ship naturally falls into the breach on a carefully directed vector. The drive then directs some of its energy to sewing up
that hole again. The act of closing the hole severs the ship’s ties with normal space and allows it to begin its jump.
The duration of a jump is fixed at the instant the jump begins, and depends on the specific jump space entered, the energy input into the system, and other factors. In most cases, jump will last a week.

During the week in jump, the responsibilities of the crew are directed toward maintaining life support within the ship, repair and maintenance of ship systems, and care of the passengers.

At the end of the week in jump, the ship naturally precipitates out of jump space and into normal space. The exact time of emergence is usually predicted by the ship’s computer and the bridge is well-manned
for the event.

In TNE they were a bit more explicit about the existence of jump space dimensions- alternate universes with different laws of physics.

The MgT 2e description has all the hallmarks of fanon made canon with no research done.

 

[whulorigan]

In TNE they were a bit more explicit about the existence of jump space dimensions- alternate universes with different laws of physics.

I don't remember the exact wording of TNE, but they may have borrowed somewhat from MT / DGP: Starship Operator's Manual which added 36 jumpspace dimensions to the 26 of the then current String Theory model, surmising that the 36 dimensions all collapsed to zero dimensionality (or near zero) shortly after the big-bang, and that the jump drive is re-expanding and accessing one (or more) of these (perhaps in a manifold in conjunction with the normal 4 spacetime dimensions) to make the jump-transition.

You would of course need at least 3 spatial dimensions and one temporal dimension in any even for the ship to continue to exist in a "normal" form during the transit, whatever the dimensional configuration.

 

[AnotherDilbert]

So it creates a bubble of hyperspace.
And an artificial singularity.
And exotic particles.
And a parallel universe.

What a completed departure from existing OTU canon and MWM's article on jump drive and what we are told in T5.

They also republished the JTAS jumpspace article...

 

[Condottiere]

This is my current view of jumpspace:

1. It's two dimensional - there's visual proof.

2. What happens when we activate the jump drive, is less tearing a hole than jemmying in a third dimension.

3. Which is done by squirting in hydrogen, to maintain that separation.

4. It's possible that the jump bubble moves in space, but exists in time.

 

[Grav_Moped]

I have no idea how Collectors works. It can apparently collect vast amounts of energy fairly quickly and release it very quickly, but it can't release small amounts of energy slowly (replace a power plant).

LBB2'77-DA1/MgT require significantly less energy since they don't need the equivalent of Pn=Jn running during the week in Jumpspace.
The baseline power requirements in those systems are much lower too (and in the former, it's completely handwaved).

The morale of the story is: Don't dig too deeply into jump physics, it doesn't add up...

This.

In '77 (and maybe MgT) it kinda did if you didn't look too closely. Otherwise... well, this is just a game that allows you to simulate science fiction, after all.

 

[Grav_Moped]

That was one possibility I had considered,
But there are a few wrinkles.
The fuel cost is extremely front loaded.
IIiRC 80 prevent of jump fuel is spent entering jump space. For a far trader that would be fuel roughly equivalent to a rocket launch.

That's how I see it, at least metaphorically.

Getting from the planet to the entry point for hyperspace is, in-game, a solved problem, and relatively cheap.
Getting into hyperspace is cutting edge and takes a heck of a lot of power, as do today's rocket launches.

Fuel/energy requirements were assigned with this metaphor in mind.