How much territory can a starship cover at maximum impulse, am I mistaken in thinking that starships fight at impulse speeds?
James
James
Impule Speed
- Thread starter James Wright
- Start date
Starships are shown to fight at warp in every series, but they ALSO can fight at impulse power. (The movies always fight at impulse, oddly enough...)
Maximum impulse is stated at somewhere around .75C (this varies depending on the reference), without transferring impulse power to warp drive. In TOS, impulse-powered shuttlecraft seem to be capable of warp 4 to 5 for a few hours.
Maximum impulse is stated at somewhere around .75C (this varies depending on the reference), without transferring impulse power to warp drive. In TOS, impulse-powered shuttlecraft seem to be capable of warp 4 to 5 for a few hours.
Maye I should've asked how long does it take a starship travelling at maximum impulse to go the distance of a starship travelling at warp 1 for 12 hours?
Sorry!
James
Sorry!
James
G
Garrovick
Guest
Try this...
http://www.ussdragonstar.com/utilitycore/warpspeeds.asp
Just the first hit on Google. There are a bunch more out there to play with.
http://www.ussdragonstar.com/utilitycore/warpspeeds.asp
Just the first hit on Google. There are a bunch more out there to play with.
The problem is, no one's ever established what maximum impulse is.
This was discussed in a fashion in this thread.
As to what warp .5 means: I posted this in the thread above.
This was discussed in a fashion in this thread.
As to what warp .5 means: I posted this in the thread above.
What kind of fuel does an impulse engine use and how long does it take a ship to use up it's impulse fuel?
James
James
The modern Tech Manuals suggest that impulse engines work by fusing deuterium with deuterium so that they get energy, and then they eject that deuterium (plus the fusion-produced helium) through some sort of coils for vaguely rocket-like thrust.
Older tech publications have suggested deuterium-tritium fusion, which in reality is easier to achieve; perhaps Starfleet did use that back in Kirk's days, but later developed the D-D fusion and got rid of the weight and complexity of a double fuel system. Or a triple one, really, since deuterium and antideuterium are supposedly also used for warp power in modern ships.
Older publications typically don't suggest a rocket-style mode of operation for the impulse engine, either. But one might choose to believe in a hodgepodge of exhaust jets, accelerator coils, and MHD taps and subspace coils that get energized by the accelerated exhaust - the balance of these different components might vary from ENT to TOS to TNG, but they might still all be there. Certainly canon is vague enough on the issue to allow for just about any interpretation.
As for how rapidly a given starship might run out of fuel (or propellant, if this is needed in addition to an energy source), we never really hear of a starship that would empty her tanks just by doing impulse drive. Voyager once ran on fumes ("Demon"), but apparently only due to using the same fuel for both impulse and warp...
Kirk got to sign fuel consumption reports in "The Deadly Years", despite his ship only performing minor sub-impulse maneuvers around a planet. He also had to sign all sorts of stuff in other episodes, of course, and we might suspect at least some of those were related to fuel consumption. Presumably, then, fuel is a critical resource, even though the amount of fuel remaining has never been a plot limitation on what action our heroes can or cannot take. Perhaps the ship was at the end of a long chain of missions in "The Deadly Years", and short on all sorts of resources, making it all the more excusable that Commodore Stocker would decide to head for the nearest starbase even through high-risk areas?
Timo Saloniemi
Older tech publications have suggested deuterium-tritium fusion, which in reality is easier to achieve; perhaps Starfleet did use that back in Kirk's days, but later developed the D-D fusion and got rid of the weight and complexity of a double fuel system. Or a triple one, really, since deuterium and antideuterium are supposedly also used for warp power in modern ships.
Older publications typically don't suggest a rocket-style mode of operation for the impulse engine, either. But one might choose to believe in a hodgepodge of exhaust jets, accelerator coils, and MHD taps and subspace coils that get energized by the accelerated exhaust - the balance of these different components might vary from ENT to TOS to TNG, but they might still all be there. Certainly canon is vague enough on the issue to allow for just about any interpretation.
As for how rapidly a given starship might run out of fuel (or propellant, if this is needed in addition to an energy source), we never really hear of a starship that would empty her tanks just by doing impulse drive. Voyager once ran on fumes ("Demon"), but apparently only due to using the same fuel for both impulse and warp...
Kirk got to sign fuel consumption reports in "The Deadly Years", despite his ship only performing minor sub-impulse maneuvers around a planet. He also had to sign all sorts of stuff in other episodes, of course, and we might suspect at least some of those were related to fuel consumption. Presumably, then, fuel is a critical resource, even though the amount of fuel remaining has never been a plot limitation on what action our heroes can or cannot take. Perhaps the ship was at the end of a long chain of missions in "The Deadly Years", and short on all sorts of resources, making it all the more excusable that Commodore Stocker would decide to head for the nearest starbase even through high-risk areas?
Timo Saloniemi
Magic, if you accept high-sublight speeds as a given. Alternatively, it's a combo rocket/warp system, which means there's no real point for the rocket to be there.
If you accept that impulse speeds are much lower than usually assumed (e.g. a hundred thousand kilometers per hour, not per second), then it runs on the deuterium-deuterium chain.
But this is a hornet's nest.
I expect it is powered by deuterium fusion, with a low level warp field maybe?
GodThingFormerly
A Different Kind of Asshole
"By way of contrast, the impulse engines can drive the ship only at sublight speeds, and can be continuously operated for about a month before exhausting impulse power fuel." - The Making of Star Trek by Stephen E. Whitfield & Gene Roddenberry (Del Rey, 1968).
A remarkably vague statement, but it is still useful as an additional data point regarding the NCC-1701's need to expend fuel/reaction mass when operating on impulse power. As to my own (spectacularly non-ca[n+1]on) opinion on the TOS Enterprise's fusion-energized impulse engines, I'm going to go with hydrogen-boron fusion for a several reasons which are mostly ST:TMP-related:
1). Gene Roddenberry contrasted the superiority of the NCC-1701 Refit's M/AM-energized impulse engines against the "old hydrogen fusion" engines in his ST:TMP novelization.
2). ST:TMP's technical advisor Jesco von Puttkamer specifically proposed boron-hydrogen fusion as one of the three preferred forms of utility power generation on 23rd century Earth - the other two being solar and geothermal - in his 1976 memo ("The 23rd Century: A Vision for Star Trek") to Gene Roddenberry which suggests that it will have become a relatively widespread, mature and safe technology by that point. This would be a major consideration for spacecraft on autonomous interstellar exploration missions, as more cutting-edge systems may contain unpleasant operational surprises that could prove fatal for starships hundreds or thousands of lightyears way from the nearest starbase.
3). The (currently) problematic ignition condition requirements aside, pB^11 fusion is relatively aneutronic in comparison to D-D/D-T fuels, which simply means that a greater fraction of the fusion exhaust product's kinetic energy can be directionalized via magnetic fields for improved propulsion efficiency. I suppose that 23rd century forcefield technology can be used to directionalize neutrons, but why inflict additional mass and complexity penalties upon the impulse engine design if you don't really have to?
TGT
I wouldn't go by that. I typed in Warp 9.975 (Voyagers top speed) and it says Voyager could traverse 100,000 lightyears in about 16 and a half years, getting to Federation space about 70,000 would take 14 years according to that, not 70. Somethings not quite right there.
Do you all remember "The Doomsday Machine"? If I remember correctly the Enterprise lost warp drive and had only impulse, Spock told Decker something about the Doomsday Machine being able to refuel while the Enterprise could not!
And it appeared like the Enterprise was having to move at maximum impulse to stay out of range of the Doomsday Machine.
James
And it appeared like the Enterprise was having to move at maximum impulse to stay out of range of the Doomsday Machine.
James
GodThingFormerly
A Different Kind of Asshole
In my mind I think that "impulse" being something more than a simple Newtonian reaction-based propulsion system!!! Otherwise, it just wouldn't make much sense!
Ever since I saw a physicist on tv point out the inconsistency of it, I've had a major geeky peeve with how silly - but common - it is for spaceships in sci-fi flim and movies to have, for some reason, both artifical gravity and a reaction-based propulsion system! (e.e; rockets, thrusters, ion engines, etc...)
And now it drives me crazy ever single time I see it - even with shows I love like Star Trek, Firefly & BSG!
Artifical gravity, anti-gravity (and tractor beams) mean gravity control - and when you can make an artifical gravity field to hold stuff down, all you need to do is turn it on it's side and strengthen it to also propel your ship!
So if you have machine on your spaceship that can make &/or control a gravity field strong to keep your boots on the deck - that same machine (or another just like it) can also double as a perfectly good non-Newtonian field drive!
Practical, working, gravity control technology would make reaction-based propulsion systems completely obsolete, and useless except maybe as a backup system if the gravity drive fails - and to still be using a Newtonian reaction-based system as the main method of (non-FTL) propulsion for a ship with working gravity tech onboard would be as anachronistic - and unnecessary & inefficent - as using a horse to pull around a perfectly functioning, fully fulled Hummer 4X4 would be!!!
But other than B5 - which had a rule that ships w/ artifical gravity technology also used gravitic drives for propulsion, and ships without used big rocket-like engines instead (and even they frakked up once in LotR with the "Valen") - I think that most spaceships, in most sci-fi, usually, almost always, will have this same inconsistant combination of both - internal gravity control the hold the crew down and yet Newtonian propulsion to make the go.
I think that the most ship designers just don't see the problem, and they and the majority of their audience don't - it's what they've always seen before, it's how a spaceship looks, it's what they (subconsiously) have come to expect - and seeing otherwise...seeing a ship with no visible "rocket" engines in the tail-end fly all around as if by magic...might, ironically, look confusing and unrealistic to most people!
Ever since I saw a physicist on tv point out the inconsistency of it, I've had a major geeky peeve with how silly - but common - it is for spaceships in sci-fi flim and movies to have, for some reason, both artifical gravity and a reaction-based propulsion system! (e.e; rockets, thrusters, ion engines, etc...)
And now it drives me crazy ever single time I see it - even with shows I love like Star Trek, Firefly & BSG!
Artifical gravity, anti-gravity (and tractor beams) mean gravity control - and when you can make an artifical gravity field to hold stuff down, all you need to do is turn it on it's side and strengthen it to also propel your ship!
So if you have machine on your spaceship that can make &/or control a gravity field strong to keep your boots on the deck - that same machine (or another just like it) can also double as a perfectly good non-Newtonian field drive!
Practical, working, gravity control technology would make reaction-based propulsion systems completely obsolete, and useless except maybe as a backup system if the gravity drive fails - and to still be using a Newtonian reaction-based system as the main method of (non-FTL) propulsion for a ship with working gravity tech onboard would be as anachronistic - and unnecessary & inefficent - as using a horse to pull around a perfectly functioning, fully fulled Hummer 4X4 would be!!!
But other than B5 - which had a rule that ships w/ artifical gravity technology also used gravitic drives for propulsion, and ships without used big rocket-like engines instead (and even they frakked up once in LotR with the "Valen") - I think that most spaceships, in most sci-fi, usually, almost always, will have this same inconsistant combination of both - internal gravity control the hold the crew down and yet Newtonian propulsion to make the go.
I think that the most ship designers just don't see the problem, and they and the majority of their audience don't - it's what they've always seen before, it's how a spaceship looks, it's what they (subconsiously) have come to expect - and seeing otherwise...seeing a ship with no visible "rocket" engines in the tail-end fly all around as if by magic...might, ironically, look confusing and unrealistic to most people!
GodThingFormerly
A Different Kind of Asshole
Isambard Kingdom Brunel's SS Great Eastern had screws, paddles and sails, and I am pretty certain that she was not the only oceangoing vessel of the era with multiple propulsion systems because nautical steam technology had not as yet sufficiently evolved to dispense completely with sails, at least as far as the paying public was concerned. Of course, it is entirely possible that Starfleet's impulse engines will - like sails and paddles - eventually become vestigial at some point in the late 24th/early 25th century, as their obviously non-Newtonian location on the Enterprise-E suggests. The Enterprise-F may have been designed and built entirely without them, but since I don't have the slightest interest in 24th century (and later) Trek I am only too happy to plead total ignorance on this particular subject.
TGT
Voyager can't travel 9.975 the whole journey.
I put in 9 and got a 65 which is closer to the premise in Caretaker.
I think Voyager never stayed in consistent high warp because they were always stopping and exploring.
Correct. There's the fact that Voyager never once in the entire series ever achieved its stated top speed, and the only time it came close, almost exploded. If you plug in a more reasonable value like, say, warp 8, you get your 70 year figure (since Voyager only had to travel 70,000 light years).
It's much safer to assume that impulse, unlike warp, is newtonian enough that a ship must ACCELERATE to or beyond the speed of light, and will remain at that speed for a good amount of time until drag from the interstellar medium slows it down. That probably explains why they were burning fuel as fast as they were: inside a solar system (where there isn't much free hydrogen) and jetting around at full impulse power trying to maintain high FTL speeds and maneuver at the same time. Picture a nuclear-powered submarine blowing a reactor hose and suddenly having to maintain flank speed against, say, a two-mile long giant crocodile just on battery power; they're gonna run out of juice VERY quickly.
Yes, 9.975 is only supposed to be for 12 hours, and obviously with damage, disrepair and lack of ability to refuel and so forth, Voyager wasn't going to be performing at the top end of the specs for a ship of her class. One thousand light years per year would have been awfully optimistic too (though she could probably hold warp factor 8 for about two weeks at a time under normal circumstances according to Rick Sternbach's article). Star Charts had her covering a little less than half that under her own power in a typical year (I think it was...438 light years or something), which seems reasonable.
The Writer's Technical Guide made it clear that regular warp drive was not a realistic option for getting home, though I can certainly understand why the crew didn't go around saying any such thing to one another.
Similar threads
