Maneuver Drive - How does it work?

[Valarian]

The impression that I get from the Traveller books I've read is that the maneuver drive "pushes" the starship/spaceship forwards in much the same way as reaction drives would. The only difference being that any acceleration over 1G is compensated for so that the ship maintains a comfortable gravity onboard. If the drive is damaged or shut down, then momentum is maintained and the ship continues on its current heading.

Does anyone use the "drive field" concept (Honor Harington / Starfire series) where, if the drive field is lost, the ship is dead in space? The drive seems to work by "riding" the ship on a gravity wave (similar I suppose to MagLev).

Which do people think is most plausible for a reactionless drive technology?

Which do people think has most possibilities in game terms?

 

[Pickles]

Stopping dead is marginally safer for the ship, as it won't crash into any planets it might have been heading towards. From an attacker's viewpoint, it makes little difference whether their target is stationary* or moving on a constant vector.

Purely from an atmospheric viewpoint, I prefer the idea that ships keep going after their magic reactionless manoeuvre drives conk out.

 

[Valarian]

Originally posted by Bromgrev:
Purely from an atmospheric viewpoint, I prefer the idea that ships keep going after their magic reactionless manoeuvre drives conk out.

Ah, but here you have the gravity well effect from the planet - so your players still have to fix the drive before they go splat in a spectacular fashion.

The "drive field" effect would be a disadvantage if you wanted to "run silent". In Traveller, you can jump to the outer reaches of a system, run your drive for a bit to pick up momentum and cut the drive to reduce emissions while you coast through the system to gather intelligence etc. With a drive field you'd be unable to do this as you need the drive field to move.

 

[mike wightman]

IMTU the maneuver drive produces a field that reduces the inertial mass of the ship, and then uses a plasma rocket to produce thrust.
If the inertial reduction field fails then the plasma rocket is reduced in effective acceleration by a considerable factor.
The ship would continue with its vector, however.

 

[Uncle Bob]

From the conservation of momentum when the wave you are riding dies, rather than have no velocity you will have the vector you had when you turned drive on. This could be on the order of 10 km/sec in the wrong direction.

 

[mctesla]

What about an Alcubierre-style warp drive? Although it's been established that the geometry of the field (and it's known variants) won't allow for faster than light travel, there's nothing that I'm aware of that would prohibit using it as a maneuver drive...

 

[Anthony]

There are other issues with the alcubierre warp drive, such as the planetary masses of exotic matter and boundary conditions that will rip nuclei apart.

 

[TheEngineer]

Hi !

Just a few more weird thoughts...

IMTU I consider thruster, jumpdrive as well as artifical gravity technology to be spacetime effects.
Travellers magic technology shapes spacetime inside and around a ship (usually only mass/matter is able to do that), so that a resulting geometry provides a gravitic effect, which drags the ship to a desired direction. Well, its not really riding on a gravitic wave, but riding on an artifically create slope of spacetime.
So, if the bending is done by thrusters in a proper way (stable, homogenous), this results a kind of quite comfortable freefall drive, if any bit of the ship and its interior is subject to the same gravitic effect=acceleration. A badly modulated maneuver drive might cause passengers to become "space sick".
And as it is an spacetime effect on the complete ships volume its indeed perfectly reactionless, volume dependent but mass independant.
In contrast artifical gravity devices are just able to create micro spacetime slopes, effecting only a very limited volume, but nevertheless providing an dragging force. This could be used to move mechanically adjected objects, which are subject to normal reaction.
Regarding the "problem" of energy and momentum conservation, it could be argued, that thruster technology just enables to "drain" other regions of spacetime, e.g. by creating a connection to an area of space, which is located in an appropriate gravitic field (as such it is very closely related to jump technology). A manuever drive would just use a remote gravitic source to move the ship. The power a manuver drive consumes, would just be used to create and regulate the "link" (like a base contact of a transistor), and thus remains nearly constant.
This could be seen as an aspect of the fact, that the basic conservation laws are properties of flat spacetime. If one starts to bend space and create wormholes without mass everything is messed up...

Anyway, its very fictional stuff and the most important part is perhaps to present players a somehow consistent picture of it all, maybe with a few nifty detail side effects of the used technology.
Thinking about stuff like above surely is ridiculous but its somehow fun, too

Regards,

Mert

 

[Pickles]

One thing which continues to bug me ... why do all Traveller ships have great big glowing engine nozzles?

 

[BillDowns]

'Coz its sexy, dude...

 

[TheEngineer]

Options:
- Glow is an easy to use standard post effect of any 3D rendering software

- The noozles are very HOT
- The noozles serve as heat radiators (ho,ho)
- The noozles are coated with a special glowing material essential for thrusting
- Kateshi radiation caused by convering space time modulation fields on the thruster surface
- Imperial Standard No. IISR-1664-A9FG-542/100 says it shall glow
- The art is just wrong

 

[Valarian]

I'd go for "Imperial Standard No. IISR-1664-A9FG-542/100 says it shall glow"

HEADLINE: Imperial Scientists make breakthrough in utlra-florescent material in order to comply with ISA (Imperial Space Authority) regulations

 

[Chaos]

Originally posted by Valarian:
I'd go for "Imperial Standard No. IISR-1664-A9FG-542/100 says it shall glow"

HEADLINE: Imperial Scientists make breakthrough in utlra-florescent material in order to comply with ISA (Imperial Space Authority) regulations

This makes sense, simply. The earliest drives used by the first Vilani spaceships glowed, because they were chemical rocket engines or something - therefore, ALL drives have to glow. It´s tradition. It has always been like that, so why change it?

 

[TheEngineer]

Its tradition to keep traditions

 

[Pickles]

I suppose it's an easy way to tell which end is the back.

 

[Valarian]

How about this ...

Thruster plates produce a gravitational anomaly behind the ship to push the ship forward. The glow warns anyone else that the plates are active and not to approach too closely.

Drive fields manipulate relative local gravitational balances. The ship is moved in relation to local gravitational sources. If the drive field goes down, there is no momentum to conserve as the ship is just stuck in its current relational position. [God help you if you have drive plates and misjump to deep space - the maneuver drive won't work as there's not enough local gravity to manipulate]

 

[Fritz_Brown]

Originally posted by Bromgrev:
I suppose it's an easy way to tell which end is the back.

 

[Plankowner]

I always figured the maneuver drive was a fusion drive, hence the glow. Gravitic technology allowed the interior of ships to maintain 1g (or whatever was comfortable). I THINK later they got called Thruster Plates, but that was after I stopped playing/reading Traveller stuff, so I am probably way out to lunch.

OK, I only posted here to pad my stats! I REALLY want to get to SS 11!

 

[Valarian]

Originally posted by Plankowner:
OK, I only posted here to pad my stats! I REALLY want to get to SS 11!

It's overrated!

 

[Commander Drax]

IMTU the maneuver drive produces a field that reduces the inertial mass of the ship, and then uses a plasma rocket to produce thrust.
If the inertial reduction field fails then the plasma rocket is reduced in effective acceleration by a considerable factor.
The ship would continue with its vector, however.

I've used something similar in my own ATU, though a wormhole at the heart of teh drive draws fuelfrom a known fuel source such as the atmosphere of a distant gas-giant, hence ships never need to refuel and can top up their jump tankage without skimming or buying fuel...