Maneuver Drives

[RossWinn]

The types and kinds of maneuver drives have varied over the different editions of Traveller. Reactionless drives are the defacto standard of Traveller, what would be two alternatives that might have different technological requirements or benefits?
Thrusters? Ion? Reaction? What are your thoughts on this question. P.S. Your answer does not necessarily need to be any “canon” option, though it can be.

 

[atpollard]

I like the Triton (Tri-modal Nuclear Thermal Rocket with LOX “afterburner” for Thrust Augmentation and a Brayton Cycle Thermal Electric generation system built in).

For the initial burn, you can use the LOX thrust augmentation to create a HIGH THRUST engine, then switch to a HIGH ISP LH2 NTR engine for sustained acceleration, then switch off the engine to conserve fuel and just use the Reactor as a POWER PLANT to operate systems and life support.

TRITON AIAA Paper

 

[warwizard]

The HePLAR drive does not generate gravetic signatures that thruster plates do, so if the enemy went heavy on gravetic sensors, there is very little of such signals to detect.

 

[kilemall]

I go kind of a mix- mdrive is mostly gravitics causing the ship to partially cut off from the universe with the effect of weighing less. Then the low level exhaust from the power plant is channeled into thrust such that it’s pushing a few kilograms and thus sort of is reaction but without reaction mass. The exhaust takes care of heat dispersion from the ship.

From a detection stand point obviously a very strong artificial gravitic field and an ever present IR possibly UV and VL emission.

I have an additional gotcha in that if the mdrive is wrecked the power plant has to shut down until a rigged exhaust is made.

 

[warwizard]

I have an additional gotcha in that if the mdrive is wrecked the power plant has to shut down until a rigged exhaust is made.

Umm, unless your ship is designed to always be thrusting (like a Bussard ram's fusion drive), then the power plant has radiators and a 0 thrust vent to handle when no maneuver is needed.

 

[mike wightman]

CT 77 ->HG79 m-drive is some sort of fusion drive using reaction mass for thrust, and can be weaponised.
HG80->81CT->TTB->ST m-drive is not defined
MT first major departure, m-drive is now thruster plates that use every bit of ridiculous handwavium in their explanation, and are now TL11 rather than TL7+, although there is a TL9 grav drive.
MT Hard Times had rules for building lower TL drives, TL7 ion engines and NTR, the pick of the bunch was the TL9 fusion rocket
TNE went back to the original intent according to Frank Chadwick and Dave Nilsen by using the HEPlaR drive, although FF&S had rules for lots of different drive types.
T4 returned to the thruster plate.
MgT has a grav based m-drive

My personal "standard" m-drive uses gravitics to reduce the inertial mass of the ship so that the ion engine or plasma rocket can achieve the m-rating.

 

[Condottiere]

You can customize them.

Which, if done properly, is kinda neat and intriguing.

 

[aramis]

At least after I started to think about it (fall 1984?), I always saw Mdrives as some form of gravitic drive, due to the TL elements on the CT-81 TL table spread. Somehow, that all the deckplans looking like turbines never sank in until after the T-Plate was canon. The lack of drive fuel mechanics was a plus, not a minus, for the style of game I wanted: something inspired by the Larson BSG and Buck Rogers, as well as Thunderbirds are Go, Space Academy, and the hardware of Space:1999... (I have always found Space 1999 itself boring as hell, but with great ships. Even when it was in first run.)

Marc has noted that Traveller wasn't intended to be Hard SF - that's a Frank Chadwick thing. And while TNE sold decently, it mostly found a new audience, and ticked off a lot of the old. C'est la' guerre.

 

[Condottiere]

I think what's contentious is that the default manoeuvre drive is anchored to a gravity well.

My issue with the Mongosian customization, is the lack of latitude.

 

[kilemall]

Umm, unless your ship is designed to always be thrusting (like a Bussard ram's fusion drive), then the power plant has radiators and a 0 thrust vent to handle when no maneuver is needed.

No, the gravitic field is tuned down and its kilogram thrust trying to push tons. The power use is mostly the field and secondarily enhancing the thrust.

 

[kilemall]

I think what's contentious is that the default manoeuvre drive is anchored to a gravity well.

My issue with the Mongosian customization, is the lack of latitude.

That darn grav limit had a lot to do with me doing mental gymnastics to avoid it’s pernicious can’t go here effect.

 

[kilemall]

CT 77 ->HG79 m-drive is some sort of fusion drive using reaction mass for thrust, and can be weaponised.
HG80->81CT->TTB->ST m-drive is not defined
MT first major departure, m-drive is now thruster plates that use every bit of ridiculous handwavium in their explanation, and are now TL11 rather than TL7+, although there is a TL9 grav drive.
MT Hard Times had rules for building lower TL drives, TL7 ion engines and NTR, the pick of the bunch was the TL9 fusion rocket
TNE went back to the original intent according to Frank Chadwick and Dave Nilsen by using the HEPlaR drive, although FF&S had rules for lots of different drive types.
T4 returned to the thruster plate.
MgT has a grav based m-drive

My personal "standard" m-drive uses gravitics to reduce the inertial mass of the ship so that the ion engine or plasma rocket can achieve the m-rating.

See? I’m not completely crazy!

What do we call that style? Mass Drive?

 

[mike wightman]

That's not a bad name... mind if I borrow it?

The reason I went with shipboard null grav modules as part of the m-drive reducing inertial mass (note reduce, not eliminate altogether, that way lies madness) and requiring an ion or plasma rocket - too many illustrations show a drive plume, I like the idea of using the m-drive as a weapon in extremis (too much Niven in my youth)

 

[kilemall]

That's not a bad name... mind if I borrow it?

The reason I went with shipboard null grav modules as part of the m-drive reducing inertial mass (note reduce, not eliminate altogether, that way lies madness) and requiring an ion or plasma rocket - too many illustrations show a drive plume, I like the idea of using the m-drive as a weapon in extremis (too much Niven in my youth)

Ya I have PA acceleration built in just cause. It’s not particularly physics passable but my players can roll with it even though they ‘know better’. Probably not weapons range PA though.

Nice side effect, the grav field distorts the outgoing emissions hence the more limited detection ranges.

Re the name, it’s our club we can do what we want. I just made up the name reading your reexpression of the same basic concept, it can stand until we come up with something better.

Ooof, gotta think of an excuse for railguns and the particle based weapons. I guess the grav drive detune during firing time trick again.

 

[Condottiere]

Has anyone tried to place gravity tiles on the ceiling for a tailsitter?

Assuming Terran norm, in theory, it should neutralize one factor of acceleration.