New drive type - the D-drive

[dalthor]

For those that follow science, dark matter is the latest thing around. Supposedly, the universe is full of dark matter, and it is everywhere. It is the "missing mass" that makes the universe work the way it does.

IMTU I've created a dark-matter drive. It allows maneuver capability with no limitations on distance from a gravity source - an M-drive without the 1000D limit.

   Drive        TL=  12  13  14  15  16
D  Dark Matter        1   3   5   7   9

At TL-12 it is capable of 1g acceleration, increasing by two gees per TL, to a maximum of 9g's at TL-16. It is essentially a thruster with no exhaust.

It masses two dtons per 100 tons of hull size, or 2 * H / 100 ton, giving 1g acceleration. Multiple that by drive rating to get final displacement. For example, to get 2g acceleration on a Beowulf (200 ton hull) would give a drive size of 8 (rating 2 * 2 * 200 / 100) = 800/100 = 8) tons.

Cost is MCr1 per ton.

Fuel is included in operations fuel, and the drive has a backup Fusion+ module that could power the drive for up to 12 days at 1g acceleration.

----

Thoughts?

 

[aramis]

If it works in Jump, too, then I can kill your planet with my D2 scout ship without any warning to you whatsoever.
If not, then it can crack the planet with a slim chance of warning by people seeing it working before I jump out...

 

[dalthor]

Ah, yes, the infamous near-c rocks thing again. Sigh.

If somebody is that desperate to be that destructive, they don't need this to do it. A G-drive or M-drive will do the same thing, just needs a lot more time to do it. There are a myriad other ways that anybody with half a mind could come up with as well.

For what it is worth, I wonder how many ideas out there don't get posted because people see some of these responses, and decide not to bother.

Anyway...

The D-drive is a maneuver drive, not usable in jump space. Like anything else, use it, abuse it, or ignore it.

For those that celebrate it, Happy Thanksgiving!

 

[dalthor]

Best analogy I have for D-drive is a jet ski. I was going to state that in the original post, but decided just to posit the drive for the initial idea.

We current earthlings currently can't detect DM at all, but the math says it exists.

Dark matter (DM) is the water, the p-plant and drive are the engine and impeller.

Drive sucks in DM, spits it out the back. DM doesn't have a physical effect on our space. Conservation of mass and all that is intact, Sir Isaac isn't rolling over in his tomb. Kinda like the space-borne equivalent of the magneto-hydrodynamic drive...

Simple enough to limit the max input/output ratio and top out the speed, maybe relative to the TL of the drive.

Anyway, some constructive feedback is appreciated.

 

[Magnus von Thornwood]

Well....

Best analogy I have for D-drive is a jet ski. I was going to state that in the original post, but decided just to posit the drive for the initial idea.

We current earthlings currently can't detect DM at all, but the math says it exists.

Dark matter (DM) is the water, the p-plant and drive are the engine and impeller.

Drive sucks in DM, spits it out the back. DM doesn't have a physical effect on our space. Conservation of mass and all that is intact, Sir Isaac isn't rolling over in his tomb. Kinda like the space-borne equivalent of the magneto-hydrodynamic drive...

Simple enough to limit the max input/output ratio and top out the speed, maybe relative to the TL of the drive.

Anyway, some constructive feedback is appreciated.

Honestly, I just figured that Dark Matter was what the M-Drive pushed against when it hit the 1% efficiency range.

And we are starting to get a better idea about how it works and we might detect it. By TL-C or so it should be figured out and by TL-F ought to be old hat. Given that I guess this could work. Assuming we can harness DM and then what other stuff can we do with it? As far we can tell, I mean as I understand it DM is pretty massive for all its undetectabilty. Maybe it is gravitons.

Nope, got no real problems with it other than what would players do with access to DM and how does it affect MATU?

 

[aramis]

Best analogy I have for D-drive is a jet ski. I was going to state that in the original post, but decided just to posit the drive for the initial idea.

We current earthlings currently can't detect DM at all, but the math says it exists.

Dark matter (DM) is the water, the p-plant and drive are the engine and impeller.

Drive sucks in DM, spits it out the back. DM doesn't have a physical effect on our space. Conservation of mass and all that is intact, Sir Isaac isn't rolling over in his tomb. Kinda like the space-borne equivalent of the magneto-hydrodynamic drive...

Simple enough to limit the max input/output ratio and top out the speed, maybe relative to the TL of the drive.

Anyway, some constructive feedback is appreciated.

Pointing out the near-C scoutship issue IS constructive criticism. If it throws dark matter as reaction mass, it has a practical maximum speed based upon how fast it can throw the dark matter. I don't remember the details of that calculation; that's a case to ask Nyrath.

 

[ThornEel]

This sounds like a good replacement to the Dean drive: functionally, it's pretty much the same, but a coherent extension of the Manoeuvre drive tech where you simply push on a bigger, foggier mass.
I wonder if it hits 1% efficiency when away from the galactic dark matter halo.

it has a practical maximum speed based upon how fast it can throw the dark matter

That's actually one of the two ways I could think of to dampen the near-c rock problem with the varied gravity drives: limit their ability to push against fast-moving masses, at least to accelerate in the same direction. Maybe slowing down shouldn't be less efficient, though - it could even be more efficient, which would help with emergency braking (and emergency braking means interesting events).

The other one was the reverse, using a fixed installation to push against fast-approaching small masses, keeping itself fixed by pushing against the local mass of, say, a planet or a star. A specialized pressor beam, if you will.
That way, worlds could easily have cheap, redundant anti-relativistic attack stations. Ideally, they would serve other purposes like launch assistance, giving antigrav to local, unpowered vehicles on the grid...
In-universe to make them more profitable, for worldbuilding to have them in as much places as possible, and you don't have to actually change how the world itself by adding it.

And we are starting to get a better idea about how it works and we might detect it. By TL-C or so it should be figured out and by TL-F ought to be old hat. Given that I guess this could work. Assuming we can harness DM and then what other stuff can we do with it? As far we can tell, I mean as I understand it DM is pretty massive for all its undetectabilty.

Some believable (but still unconfirmed) results I read about supposedly detected those particles annihilating each-other, as ambient gamma radiation from the galactic core. If those get confirmed by further observations, it would help confirm the model with massive particles interacting only with each-other.
That would mean that, yes, you could use them as a power source: collect them with a fancy grav manipulator and ram them into each-other until gamma ray goodness comes out.
You'd pull them from a large volume, given the density of dark matter, though total conversion works in your favour. (A devious referee may imagine an interdiction engine collecting all the dark matter in the region to strand enemy drives...)

Or we could keep the drive low on details, just in case working theory changes again. Which is actually what the Collector sounds like, put that way.

 

[McPerth]

Dark matter (DM) is the water, the p-plant and drive are the engine and impeller.

Drive sucks in DM, spits it out the back. DM doesn't have a physical effect on our space. Conservation of mass and all that is intact, Sir Isaac isn't rolling over in his tomb. Kinda like the space-borne equivalent of the magneto-hydrodynamic drive...

If it throws dark matter as reaction mass, it has a practical maximum speed based upon how fast it can throw the dark matter.

And we have the 1889 ether propeller...

In fact, the theory about the dark matter always sounded to me as retourning to the ether theories, just changing the name (sure you've guessed I'm not a physics expert), and the explanation about this engine made me remeber the ones about the ether propeller

 

[dalthor]

Was looking over this thread, working on a ship for MTU, and starting thinking about relative speed and damage, with regard to the whole near-c rock thing.

Ignoring globes, Traveller has no shield technology, per se. Assuming a ship successfully accelerated to 10% of light speed, what kind of damage would occur if it hit

a) The remnants of a sand caster cloud?

b) A marble-sized rock?

c) A fist sized rock?

Hmmmm...would size even matter in this instance? I can't begin to imagine the energy generated by that impact.

Help?

 

[flykiller]

Assuming a ship successfully accelerated to 10% of light speed, what kind of damage would occur if it hit

a) The remnants of a sand caster cloud?

a sand-grain-sized hole continuously through the ship, with a sand-grain-sized plasma jet out the last hole.

b) A marble-sized rock?

a marble-sized hole continuously through the ship, with a marble-sized plasma jet out the last hole.

c) A fist sized rock?

a fist-sized hole continuously through the ship, with a fist-sized plasma jet out the last hole.

 

[aramis]

Ignoring globes, Traveller has no shield technology, per se. Assuming a ship successfully accelerated to 10% of light speed, what kind of damage would occur if it hit

Actually, it does. See CT Beltstrike.

 

[mike wightman]

Ignoring globes, Traveller has no shield technology, per se. Assuming a ship successfully accelerated to 10% of light speed, what kind of damage would occur if it hit

Help?

How heavily armoured is your ship?

Is it designed with extra armour at the front to absorb the impacts?

Alternatively you could use the repulsor technology available in most versions of Traveller to push the small stuff out of the way.

The screen technology that Aramis alludes to as mentioned in Beltstrike is the mention of the maneuver drive of Traveller ships generating a screen that deflects particulate radiation. Such a screen has a real world basis - there have been proposals to surround spacecraft with a plasma held in a magnetic field to absorb or deflect solar radiation.

 

[Kaeto]

Then there is the D.A.V.E.* drive for interstellar travel. While it does require the passengers and crew travel in low berths it can still travel 1,000 light years in 6 months time.


(* Dangerous And Very Expensive)

 

[flg]

If it works in Jump, too, then I can kill your planet with my D2 scout ship without any warning to you whatsoever.
If not, then it can crack the planet with a slim chance of warning by people seeing it working before I jump out...

Does that really matter though?

I think the best reason that nobody has, can, or would use "near-c rocks/ships" to attack planets is that if they did EVERYONE would retaliate and annihilate those responsible. Plus, anyone else could just do the same thing to them too, so it's its own deterrent.

 

[aramis]

Does that really matter though?

I think the best reason that nobody has, can, or would use "near-c rocks/ships" to attack planets is that if they did EVERYONE would retaliate and annihilate those responsible. Plus, anyone else could just do the same thing to them too, so it's its own deterrent.

It's important because it only takes one madman with a 0.2 C shuttle to kill an entire world.

Since Traveller lacks draconian restrictions on who can get a ship, it's most likely that the ships can't reliably do it.

 

[Condottiere]

How much of a running start do they need?

For the casual kamikaze, you could have a speed limiter embedded in the bridge controls, that prevents the vessel from breaking a certain velocity.

 

[Vargas]

Be advised that the Dillingham Drive from the Thousand Suns RPG is referred to as the D-Drive.

I'm just saying is all . . .

 

[flg]

It's important because it only takes one madman with a 0.2 C shuttle to kill an entire world.

Since Traveller lacks draconian restrictions on who can get a ship, it's most likely that the ships can't reliably do it.

Yes, but that's because Traveller ignores realism.

Said shuttle would be annihilated by the first interplanetary dust particle it encountered (which Traveller ignores). And M- (or D-) Drives usually ignore the mass of the object they're trying to move, which would hinder the use of large asteroids as near-C rocks. Plus it ignores the fact that the drives would generate heat, and would probably break down if they were applies for such long periods.

 

[flykiller]

Yes, but that's because Traveller ignores realism.

it mildly ignores some aspects of reality as presently understood, certainly.

social standing could be used to control who gets ships. but traveller only lightly applies any concept of social standing.

Said shuttle would be annihilated by the first interplanetary dust particle it encountered

no. at high enough speeds the dust particle simply would pass through.

 

[robject]

Dalthor, is there any downside to using this drive? Any tradeoffs?