The Enterprise-D's maximum sublight velocity/acceleration.

[Roondar]

From our thread on the Bre'eel moon we have come to the following figures on the E-D's tractorbeam:

Secondly, since we now know the moons most likely mass, we can finalize the E-D's maximum tractorbeam output.

To make an object weighing 1 * 10^16 KG move by 92 m/sec requires 4,23 * 10^19 J, or in the ten seconds they took, 4,2 * 10^18 watt - aka ~1 GT/sec.

This is an impressive number. For the purposes of this thread I'll assume this number to be equal to the maximum power the E-D can apply to it's sublight propulsion system. We'll assume the E-D weighs 6.5 million metric tons (i.e. 6.5 * 10^9 KG). If they use their warpfield to reduce mass this will naturally increase the endspeed and acceleration.

Naturally there is no real 'top velocity' we can name, since theoretically the ship will keep accelerating (albeit at an ever slower rate) as it approaches lightspeed, until it is out of fuel. I've therefore limited the velocity to the one they would achieve after putting in 'all they've got', or the earlier calculated 4,2*10^19 J over 10 seconds.

For the E-D without mass lightening, this would mean they would reach a maximum velocity of 113679 m/sec (per E= 1/2m * v^2) in ten seconds time.

With mass lightening the situation is a tad more difficult because we don't know the exact mass of the E-D while under such a field. If we assume the E-D can do what to itself what it could do to the Bre'el moon:

Near as I can tell with the latest mass estimates from the Bre'eel moon size thread, that object's mass was reduced by 4 million times! Now applying that to the E-D herself, that means that every time she puts up a warp field, she reduces her apparent inerital mass from 6.5 million metric tons down to a mere 1.625 tons! That certainly explains many of the incredible high-speed maneuvers and accelerations we have seen over the course of all 5 Trek series.
-Mike

We'd get an velocity of 289638821,3 m/sec (per E=mc^2/sqrt(1-(v/c)^2) - mc^2). Which leads me to believe the weight reduction on the E-D during normal operation is likely a lot less. The E-D doesn't ever travel at 96% of lightspeed during sublight operations.

Sadly I don't think we'll get a conclusive result here - 96% speed of light sounds like it is too high but we have no other masslightening figures.

On the other hand, the E-D was being pushed to the max to move that moon so it's conceivable the normal 'safe' limits on the mass alteration are a lot lower.

[l33telboi]

One thing, if I remember some of the older threads correctly, the Kirk-era Enterprise had independent power production for the sub-light engines. I believe the sub-light portion was based around twin fusion reactors (?) while main power comes from the warp core, or anti-matter reactor if you want to use more common terminology.

I could be wrong about that though. It might be a design feature limited to the Kirk-era Enterprise.

So I'm not entirely sure you can assume the peak main-reactor output can be shunted to the sub-light drives. It is after all, entirely possible that those kinds of power outputs from the sub-light thrusters would rip the vessel or thruster assembly apart.

But like I said, that’s mostly speculation on my part.

[Roondar]

One thing, if I remember some of the older threads correctly, the Kirk-era Enterprise had independent power production for the sub-light engines. I believe the sub-light portion was based around twin fusion reactors (?) while main power comes from the warp core, or anti-matter reactor if you want to use more common terminology.

I could be wrong about that though. It might be a design feature limited to the Kirk-era Enterprise.

So I'm not entirely sure you can assume the peak main-reactor output can be shunted to the sub-light drives. It is after all, entirely possible that those kinds of power outputs from the sub-light thrusters would rip the vessel or thruster assembly apart.

But like I said, that’s mostly speculation on my part.

Well, this is not the peak-reactor output we're looking at. This is the output of the ship when attempting to tractor an asteroid moon.

Logically this is limited to two points: the E-D's engine output and the E-D's tractorbeam output. Dialog indicated that it was the tractorbeam which could not handle the strain of being used with the engines at full power.

Since they managed to use the ship to push/pull the asteroid in question, I'm assuming that the engines are in fact capable of that output.

And since they nearly blew out the tractorbeam emitter in the process, I assumed it as an acceptable maximum engine load situation.

Also: Startrek ships have two distinct sublight engine systems, being thrusters (which are rarely used and always specifically named when they are) and impulse (which is what we are talking about here). The assumption is that impulse drive is merely a different form of thrusters in action, but if that is so why are there even two seperate thruster systems?

[l33telboi]

Since they managed to use the ship to push/pull the asteroid in question, I'm assuming that the engines are in fact capable of that output.

Ah, I see. They used the impulse drives to actually push the moon, and the tractor to simply 'grab' it?

Also: Startrek ships have two distinct sublight engine systems, being thrusters (which are rarely used and always specifically named when they are) and impulse (which is what we are talking about here). The assumption is that impulse drive is merely a different form of thrusters in action, but if that is so why are there even two seperate thruster systems?

This I know actually, I merely referred to the impulse drives as thrusters because I seem to recall that impulse is basically a plasma-drive, which basically means jettisoning high-energy plasma out the back to generate thrust - ergo thrusters.

But I can see how it'd get a bit confusing if you refer to them as thrusters when they already have another system in place that's specifically called this.

[Roondar]

Since they managed to use the ship to push/pull the asteroid in question, I'm assuming that the engines are in fact capable of that output.

Ah, I see. They used the impulse drives to actually push the moon, and the tractor to simply 'grab' it?

As far as I can tell, this is true. As I recall Geordi was worried about two systems failing: the tractorbeam as it was over it's 'thermal limits' and the impulse engine, which was being pushed into (over?) it's safety limits.

Also: Startrek ships have two distinct sublight engine systems, being thrusters (which are rarely used and always specifically named when they are) and impulse (which is what we are talking about here). The assumption is that impulse drive is merely a different form of thrusters in action, but if that is so why are there even two seperate thruster systems?

This I know actually, I merely referred to the impulse drives as thrusters because I seem to recall that impulse is basically a plasma-drive, which basically means jettisoning high-energy plasma out the back to generate thrust - ergo thrusters.

But I can see how it'd get a bit confusing if you refer to them as thrusters when they already have another system in place that's specifically called this.

It could also be that Impulse drive is not 'just' a plasma-drive after all. This would coincide with the total lack of change in brightness of the drive when they accelerate.

[Mike DiCenso]

It could also be that Impulse drive is not 'just' a plasma-drive after all. This would coincide with the total lack of change in brightness of the drive when they accelerate.

Actually, in "Deja Q", "Booby Trap", and "Preemptive Strike" [TNG, season 7, among others, the impulse engines do act as rockets. In the aforementioned episodes, as well as ST:TMP, we see the impulse engines glow significantly brighter when they are throttled up, and are specifically mentioned as applying thrust. In "Evolution" [TNG, season 3], the main star drive section impulse engine on the E-D is used to apply thrust against the ship's velocity vector to slow it down and try and prevent a collision between the ship and a stream of stellar matter. In "Booby Trap", the ship's main impulse engine glows and apply thrust to overcome inertia briefly in the bid to escape the Menthars' aceton assimilator trap. All this indicates that for the most part, the impulse engines do act as conventional, plasma spewing rockets.
-Mike

[Mike DiCenso]

One thing, if I remember some of the older threads correctly, the Kirk-era Enterprise had independent power production for the sub-light engines. I believe the sub-light portion was based around twin fusion reactors (?) while main power comes from the warp core, or anti-matter reactor if you want to use more common terminology.

I could be wrong about that though. It might be a design feature limited to the Kirk-era Enterprise.

So I'm not entirely sure you can assume the peak main-reactor output can be shunted to the sub-light drives. It is after all, entirely possible that those kinds of power outputs from the sub-light thrusters would rip the vessel or thruster assembly apart.

But like I said, that’s mostly speculation on my part.

Actually, in ST:TMP, the matter-antimatter reactor's power can be diverted into the impulse drive. But otherwise, in both the TOS and TNG-eras, they speak of the impulse engines and warp drive as completely seperate, independant power generation and drive systems.
-Mike

[Mike DiCenso]

We'd get an velocity of 289638821,3 m/sec (per E=mc^2/sqrt(1-(v/c)^2) - mc^2). Which leads me to believe the weight reduction on the E-D during normal operation is likely a lot less. The E-D doesn't ever travel at 96% of lightspeed during sublight operations.

Sadly I don't think we'll get a conclusive result here - 96% speed of light sounds like it is too high but we have no other masslightening figures.

On the other hand, the E-D was being pushed to the max to move that moon so it's conceivable the normal 'safe' limits on the mass alteration are a lot lower.

Actually, we have seen in ST:TMP that the refit NCC-1701 was able to around .73c based on the 1.8 hours it took for the ship to travel from Earth to Jupiter on impulse power at warp point 5 acceleration. Later in the movie, after the wormhole incident, the ship is said to be back on impulse at warp point eight, indicating a much higher acceleration and speed.

If we take the 19 minute BoBW time for the E-D to travel from just beyond Saturn to Earth run intercept of the invading Borg cube as the result of relativistic effects, then you have a speed in excess of .90c., possibly as high as .95c.

So I can accept that .96c is possible, even if that means pushing the ship's sublight drive to the breaking limit.
-Mike

[Roondar]

We'd get an velocity of 289638821,3 m/sec (per E=mc^2/sqrt(1-(v/c)^2) - mc^2). Which leads me to believe the weight reduction on the E-D during normal operation is likely a lot less. The E-D doesn't ever travel at 96% of lightspeed during sublight operations.

Sadly I don't think we'll get a conclusive result here - 96% speed of light sounds like it is too high but we have no other masslightening figures.

On the other hand, the E-D was being pushed to the max to move that moon so it's conceivable the normal 'safe' limits on the mass alteration are a lot lower.

Actually, we have seen in ST:TMP that the refit NCC-1701 was able to around .73c based on the 1.8 hours it took for the ship to travel from Earth to Jupiter on impulse power at warp point 5 acceleration. Later in the movie, after the wormhole incident, the ship is said to be back on impulse at warp point eight, indicating a much higher acceleration and speed.

If we take the 19 minute BoBW time for the E-D to travel from just beyond Saturn to Earth run intercept of the invading Borg cube as the result of relativistic effects, then you have a speed in excess of .90c., possibly as high as .95c.

So I can accept that .96c is possible, even if that means pushing the ship's sublight drive to the breaking limit.
-Mike

For TMP (and possibly BBoW - they could have used a high 'exit speed' for instance) we're talking about the Enterprise using it's warpengines as an 'assist' to reach these speeds, which is not really what I've calculated.

To clarify, I don't feel they won't have the capacity to reach 0.96c eventually (every spacevehicle would be capable of doing that, fuel and time permitting). I just don't feel they'll be able to do it in 10 seconds using just the impulse engines - warpfield or no warpfield.

We've seen the E-D accelerate before and it sure didn't look like it'd hit lightspeed in mere seconds ;)

[Mike DiCenso]

Actually, there is little or no evidence to indicate that the warp drive itself was used to aid in either of those two examples, other than that in ST:TMP, the E-1701 was using power generated from her warp core to power the impulse engines instead of the fusion reactors.

In "Relics", the E-D in escaping the Dyson sphere on just 60% impulse power rockets away from 150.000 km altitude above the star to the entrance portal some 100 million km away in just minutes time, though the actual timing from the episode suggests low-level FTL travel. However, I am willing to assume reasonably that some of the expected 5-6 minutes time was cut.
-Mike

[Mike DiCenso]

Also: Startrek ships have two distinct sublight engine systems, being thrusters (which are rarely used and always specifically named when they are) and impulse (which is what we are talking about here). The assumption is that impulse drive is merely a different form of thrusters in action, but if that is so why are there even two seperate thruster systems?

The thrusters are for very low-level accelerations, as well as attitude control, just as our current-day spacecraft do. The space shuttle orbiter, for example, has two gimbled 27 kN (6,000 lb) thrust Orbital Maneuvering Engines (OMS) . But it also has much smaller reaction control rockets of 870 and 24lb thrust (3.875 kN and 106.8 N respectively) for fine attitude control and maneuvers. The latter being very good for manuevering, like close proximity operations and docking with a space station or other spacecraft. And so it is with the E-D, with big, powerful impulse engines and smaller reaction control thrusters.
-Mike

[Roondar]

Actually, there is little or no evidence to indicate that the warp drive itself was used to aid in either of those two examples, other than that in ST:TMP, the E-1701 was using power generated from her warp core to power the impulse engines instead of the fusion reactors.

In "Relics", the E-D in escaping the Dyson sphere on just 60% impulse power rockets away from 150.000 km altitude above the star to the entrance portal some 100 million km away in just minutes time, though the actual timing from the episode suggests low-level FTL travel. However, I am willing to assume reasonably that some of the expected 5-6 minutes time was cut.
-Mike

I'm going to have to disagree here. In TMP the Enterprise crew specifically calls out speeds as partial warpfactors. Since they never do that again but instead call out the regular and expected calls like '1/4 impulse', I'm taking that to mean they did in fact use the warpdrive as an assist - if not as the actual propulsion method.

In BBoW I'm pretty sure everyone aboard knew it was vital to reach earth as soon as possible. I've always taken the low time to reach Earth as a consequence of the E-D exiting warp at a much higher than normal velocity (near c instead of the usual near-standstill).

As for Relics, doing ~100 million KM in five minutes ain't gonna work sublight so that's not a very good example since it's widely established by characters in ST that impulse is in fact limited to speeds lower than light. And even the six minute estimate puts the acceleration to near-c as much worse than what was suggested earlier.

There is a world of difference between reaching 0.96c in ten seconds and reaching 0.9xc in a few minutes, power wise.

[Mike DiCenso]

Yes, they use the "warp point five" and other similar statements. But then again, in ST:TMP they say and do things we almost never hear before or since. The reference to shields as "screens" and or use the terminology seperately. Furthermore, the warp drive was not available, but the warp core and some power from it were.
-Mike

[2046]

In BBoW I'm pretty sure everyone aboard knew it was vital to reach earth as soon as possible. I've always taken the low time to reach Earth as a consequence of the E-D exiting warp at a much higher than normal velocity (near c instead of the usual near-standstill).

Saturn was not growing on screen appreciably, though, which puts us back to mad acceleration. Just from screwing around with Celestia, you can't get much above 0.1c at a good distance from Saturn before it starts growing in the frame at a good pace. 0.2c is right out.

As for Relics, doing ~100 million KM in five minutes ain't gonna work sublight so that's not a very good example since it's widely established by characters in ST that impulse is in fact limited to speeds lower than light. And even the six minute estimate puts the acceleration to near-c as much worse than what was suggested earlier.

Can we presume a warp jump, or does the context reject that possibility?

[Mike DiCenso]

There is nothing I know of in that entire sequence that even remotely hints at a warp jump somewhere on the way. If they could have done that, they would have and saved critical minutes. Furthermore, the ship is stated as still being partially crippled, with only 60% impulse power.
-Mike