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Why not, then, use a stable warp field at sublight speeds to maneuver?
[ July 14, 2001: Message edited by: Stingray ]
Posted by Siegfried (Member # 29) on :
Well, according to the TNG Technical Manual, the impulse drive system used in the Galaxy-class includes a a subspace driver coil that creates a weak subspace field around the ship to lower the ship's mass so that's it easier to move at impulse. As such, there wouldn't be a need for the nacelles to stay energized since the impulse system is capable of generating the a sufficient field on its own.
The short answer is that I have no idea to even begin guessing about the nacelles staying energized. There's no real reason because I doubt it takes that long to energize them to jump to warp in an emergency.
Posted by The_Tom (Member # 38) on :
Presumably the vertainium-technobabbleide itself emits the blue light when soaked in electroplasma, so it's reasonably simple to assume there's a lingering current running to them at all times. The core is alive and pumping pretty much always, but the ship mightn't tap 100% of its power and a bit of excess might continue trickling to the nacelles.
Alternatively, vertanium-technobabbleide could be somewhat phosphorescent even once the power heading out to it is cut and keep on glowing unless there's a concerted effort to shut down everything.
[ July 14, 2001: Message edited by: The_Tom ]
Posted by Stingray (Member # 621) on :
That's all well and good Siegfried, but the part about slowing down/stopping/going backwards (in the case of every starship) or moving in a certain direction like up or down (Miranda, Excelsior, Connie, others) and side to side.
The impulse subspace thingies would only make it easier for the ship to move, not have any say in which direction the ship would go. And extra or weak current thing would neccessitate a fading effect, and TNG/DS9/VOY all show blue lights of constant brightness.
A modification: The RCS quads work for relatively acceptably slow maneuvers (orbital insertion/spacedock obviously). For combat and other sudden shit-hitting-fan moments, there's the warp fields at impulse.
Posted by Wes1701E (Member # 212) on :
because it looks cool
Posted by Siegfried (Member # 29) on :
Well, the impulse subspace field coils are used to make the ship easier to move. But the main the impulse engine still provides the thrust to move the ship. I think the three assemblies for the impulse propulsion system are the reactors, subspace field coil, and the vectored thrust nozzle. The power from the reactor energizes the field coils which produces the field and supplies power to the vector thrust assembly which propels the ship. I think there was a thread on this forum from a while ago that explains possible ways as to how the impulse engines are able to provide thrust in different directions.
I agree that the reaction control system is used for minute changes in direction and other such fine maneuvers. Those things aren't designed to be a main propulsion system, but rather they're designed to be used in situations where impulse power is too much. Like when the Enterprise investigated the interior of the asteroid in "Pegasus," that was done on thrusters. To avoid Junior in "Galaxy's Child," that was done on thrusters until Junior started chasing the ship. And of course they're docking maneuvers that require the use of thrusters (also according to the Tech Manual is that there are mooring tractor emitters in each RCS thruster position).
Tom, it also seems to me that there is also a plasma stream being sent to the nacelles. I forget the episode name, but in one episode David Kwan kills himself by jumping into a plasma stream from the nacelle tube room. Since the ship was at impulse, why was there still a plasma stream present for Kwan to jump into? I guess this leads to the point that the ships are wasting power by constantly supplying plasma to the nacelles.
Posted by Ryan McReynolds (Member # 28) on :
Incidentally, I don't remember any canon suggesting that the impulse engines ahve subspace coils... I've got no problem with simply saying they don't and use the warp coils for impulse mass-reduction/maneuvering as well, which would explain the blue glow with no problem.
Posted by Siegfried (Member # 29) on :
True, there's been next to no discussion of the impulse drive system in Star Trek aside from saying that they're powered by fusion reactors.
Posted by Siegfried (Member # 29) on :
I guess I'll add one more post to this subject. I watched TNG's "Parallels" tonight and this thread stuck in my mind as I watched the shuttlecraft scenes. Worf was using a Type 6 shuttle and was cruising through space at impulse speed. Yet, the nacelles were glowing blue. In fact, all the shuttlecrafts that have had grilles on their engine pods have had them glow blue at impulse as well. This shuttlecrafts also do not have any visible impulse engines on them. So it seems that these engine pods perform dual duties with being warp and impulse engines.
Posted by Dax (Member # 191) on :
No, the Type-6 shuttles definitely have dedicated impulse engines. There's an unusually accurately labeled schematic in the Fact Files that's shows their location. I can't be bothered at the moment, but if you're interested, I'll scan it in for you.
Posted by PsyLiam (Member # 73) on :
Are they in the same place as the ST V shuttles? I'd guess so, since it's a modification of one of the models from that film.
And you can see the Impulse engines quite clearly in ST V. They flash brightly when Sulu accelerates towards the Enterprise.
Posted by Siegfried (Member # 29) on :
Ack, I give up.
Posted by Dax (Member # 191) on :
Yeah, the Type-6 impulse engines are located in the panelling on the aft end of the shuttle. The "nozzles" are just on the perimeter of the entry hatch and there's small "impulse intakes" on the fore of the panelling.
I'm pretty sure the ST-V shuttle is the same.
Actually, this setup is sort of similar to the Danube-class.
Posted by Timo (Member # 245) on :
This could simply be further support for the idea of mass reduction fields.
-the TNG TM says such fields exist
-O'Brien describes their use in "Emissary" (although he gives no indication that these are standard starship hardware)
-the shuttles, even the tiniest shuttlepods, have nacelles
-the Defiant shuttlepod's nacelles (or cheek extensions) can erect a subspace field, as shown in "Destiny"
So perhaps the nacelles are there in the supposedly sublight shuttles solely for the purpose of reducing the mass of the craft by erecting the subspace field, while in the larger shuttles the nacelles create both the mass-reduction field AND the propulsive field (hence, they have to glow blue at impulse). The separate nozzles on the back wall of the ST5/TNG shuttle mockups would just be part of the impulse propulsion system, not the entirety of it.
Would a starship need separate coils in the impulse engines for mass reduction? Couldn't it use the nacelles themselves (thereby explaining the "idle glow")? Perhaps there simply is redundancy there. The only time we have seen a modern ship's nacelles devoid of the glow yet the rest of the ship still operational would be TNG "Skin of Evil", where a dilithium swap required such a shutdown. Voyager's nacelles have also been dark now and then, but at those times the ship was dead in space.
Arguably all nacelle-equipped ships and shuttles would be capable of mass reduction. And this would help immensely in explaining how Kirk's ships could maneuver at sublight, without having gigantic fuel tanks. Perhaps the old Enterprises did not have special mass-reducing coils, but they should have been able to use their regular warp coils for the purpose. Heck, O'Brien apparently used the *shield generators* of DS9 for that...
As for the idle glow being constant in intensity... Well, even the "idle current" might be sufficient to trigger a threshold reaction of some sort, one that always produces the same kind of glow past the threshold. There's no need to assume that the intensity would really be a function of plasma current, now is there?
Timo Saloniemi
Posted by Wes1701E (Member # 212) on :
yep. It looks cool.
Posted by Shik (Member # 343) on :
I'm watching "Eye Of The Beholder" right now (S7 TNG where Troi relives the murder empathically & the guy jumped into the plasma stream)...
A scene just played where Troi, Geordi, & Data were examining the "crime scene" in the nacelle. The WPS was obviously shut down because there was no plasma flowing from the injectors. As they moved to a wall, we saw Troi framed by the warp coils & the exterior grill.
The grill itself was still blue even without the plasma flowing. So.
Posted by Siegfried (Member # 29) on :
Well, the warp field grilles are blue on the interior when the plasma stream is powered down. However, the exterior seems to be a grayish to copperish color. "Contagion," "Unification," and "10010101" all showed scenes where the Enterprise powered down her nacelles and the grilles turned into the aforementioned color.
On a side note, I used to own a die cast Enterprise-D toy that allowed saucer separation. The warp field grilles on the nacelles were painted copper instead of blue.
Posted by David Templar (Member # 580) on :
Maybe those electroplasma really like floating around those nacelles, even when the injector is shut off. There was that time when the Ent-D lost all her subspace equipement due to that brother and sister duo, they spoke of 'saturating the nacelles'. I guess those things holds electroplasma really well. Perhaps they need to completely purge the nacelles to get rid of the blue glow.
Posted by Jack_Crusher (Member # 696) on :
First of all, the blue glow in the warp engines, even while not in use, are glowing, because "the engines are being kept warm" so the ship can go to warp quickly.
Secondly, while at warp speeds, the star ship "turns" by the plasma flow into one nacelle being more than that of the other nacelle. For example, if the Enterprise was at warp 5, and Captain Picard ordered the ship to go left, after the nameless ensign piloting the ship inputted the command into the helm computer, the computer would route more warp plasma the the port (left) warp nacelle, than to the right nacelle, thus producing a heavier warp field on the left side of the ship than on the right side. This would cause the Enterprise to go left, and when the desired course had been achieved, the computer would equalize the plasma flow to both nacelles, causing the Enterprise to go straight.
Third, and lastly, the fusion reactors that power the impulse engines in Federation star ships produce an energetic plasma, that is then passed through a subspace accerator coil, which produces a non-propulsive subspace field, that lowers its ships' apparent mass, making the impulse engines' job somewhat easier.
Posted by Da_bang80 (Member # 528) on :
how does that thing lower the mass of the ship? try to dumb it down a little too. i'm not that good at understanding this technical star trek stuff
Posted by Jack_Crusher (Member # 696) on :
For a minute explination, see the 1/2001 issue of Star Trek: The Magazine and read the stuff on page 43 (no, I mean 47. na, i'm just kidding.)
quote:
The future is the past, the past is the future; Temporal paradoxes give me headaches. Capt. Kathryn Janeway
Posted by Ryan McReynolds (Member # 28) on :
quote:
Originally posted by Da_bang80:
how does that thing lower the mass of the ship? try to dumb it down a little too. i'm not that good at understanding this technical star trek stuff
We don't know how it lowers the mass... if we did, we'd build one in real life. 
That said, it probably "hides" part of the mass in subspace, so that that only a fraction remains in realspace to be pushed around the old fashioned way. Bob Mercer and I, along with others at various times, have figured it would have to lower the mass by a factor of several million in order to not expend the ship's entire fuel supply in one 0.25 c jaunt.