Impulse Drive, Therories on how it works?

[Timo]

Then again, that manual also carefully explains how phasers don't work at warp, and how the saucer can't move at FTL on her own for long - things directly at odds with what we see (we see the phasers-at-warp in every Trek show other than TNG, to be exact).

Any numbers on the drive might be similar "deliberate misdirection" aimed at Klingon spies who enjoy access to amazon.com. At least the numbers pertaining to phaser output seem to be that!

That said, the Manual speaks of a single main tank holding a conveniently utterly unknown quantity of deuterium, and of 32 auxiliary tanks of 113 m3 or 9.3 tonne capacity. Fudge that with AG or forcefield compression tech to decide how much heavy hydrogen there really is in those tanks, and you still can't defeat the rocket equation. That bit must come from some other use of such technologies, such as in reducing the mass of the ship (and fuel and propellant) to be moved, or increasing the mass of the propellat being expelled. Or from the thing not being a rocket to begin with.

The contract specs also call for the ability to fly at 0.92+ c using 180+ mc subspace driver accelerators... Actual performance specs are not revealed.

Timo Saloniemi

 

[Ronald Held]

I did not do the calculation because I already know you could not get anywhere close to .25 c.

 

[Henoch]

The green flare is not from an oxygen reaction, so, some other chemical agent(s) is needed for the substitute fuel.
I conclude that the shuttle substitute fuel from the phasers is not deuterium. It is something else or mixed with something else. (Perhaps, pergium, or is a technobabble substance like pergium used as a power source for phaser which is drained into the shuttle tanks.) I think we need an analysis on hand phasers to further resolve this issue in another thread.

 

[Leathco]

I figured it was a fusion reactor, and the red glow was a giant heatsink mounted externally flush with the hull, redirecting the heat into space. Something like a heatsink on a current day CPU.

As far as speed, I don't think impulse can even hit light speed. We never hear a call for light speed, just for full impulse, half impulse, quarter impulse. If I recall, Warp 1 is light speed.

 

[Henoch]

If I recall, Warp 1 is light speed.

Unless you use the Cochrane Factor/Variable, then it can be anything you want including less than light speed.

As far as speed, I don't think impulse can even hit light speed.

It depends on which era you are watching, but the later series support your thinking. As said in TOS, sleeper ships became obsolete by 2018 for interplanetary travel in the solar system, and warp drive was discovered around 2060. The era of space exploration between those dates was most probably using impulse drives inside our own solar system using this theory. You never travel outside the solar system and have first contact with traveling Vulcans. Or...

TOS hinted that impulse drive may be faster than light in several examples. Back in TOS, the impulse drive consumed fuel and was "slower" than warp drive, and warp drive didn't worry about fuel and was "super" fast depending on the speed of the plot. I like to think that the impulse drive was the early technology for space exploration perhaps up to a maximum of 5-10 times the speed of light, and could only be maintained for a limited time in early flying fuel-can-type ships. This theory allows the exploration to near stars before we find Vulcans. YMMV

 

[Timo]

If we further assume that subspace radio is quite a bit more difficult to invent than warp drive, then we can have all sorts of STL explorers from Earth shaking hands, hooves or tentacles with aliens before 2063 - but failing to inform Earth of the fact until decades after the fact, due to the lightspeed commlag, or even crippling comm range issues.

This would also help explain how only the invention of warp drive deprives civilizations of their virginity as regards interstellar contact: only truly exceptional civilizations come up with devices that can eavesdrop on interstellar communications before the first warp flight.

Our heroes did not indicate in the "Space Seed" teaser that the DY-100 generation of ships had never gone interstellar. All they stated when learning that they were facing a ship of that type was that it must be a "derelict" or in alien hands. This could follow from multiple assumptions, but the heroes don't initially realize this is a sleeper ship, so their one and only assumption might be "fine, so this is one of the early interstellar ships, but since it's been so many centuries, the crew must be dead".

Indeed, given the pronounced lack of surprise, I'd actually assume that the primarily interplanetary DY-100 had indeed been credited with a few interstellar attempts. Perhaps they were all declared failures. Perhaps there were some successes, but none resulted in reports of contact with aliens before 2063. Nobody ever claims there were no crewed interstellar flights at any point before 2063, only that the Charybdis mission of 2037 was a mere "attempt" at leaving Sol.

But if the post-2018 Charybdis is an "attempt", and only the third one, where does that leave the pre-2018 DY-100? Were the two previous attempts/failures made with that tech? (They'd be rather famous cases, then, for their rarity, not easily fitting the "Space Seed" complacency on meeting a DY-100 in deep space.) Or did the older tech remain in use on interstellar sorties after the 2018 propulsion revolution, thus justifying our heroes' lack of surprise?

Or is the lack of surprise at meeting a DY-100 derelict between the stars the result of those ships being used extensively as derelicts in interstellar work? That is, as uncrewed probes, such as the later Woden? Perhaps only post-2018 propulsion warranted attempts at crewed flight, with or without cryosleep.

Timo Saloniemi

 

[MAGolding]

If we further assume that subspace radio is quite a bit more difficult to invent than warp drive, then we can have all sorts of STL explorers from Earth shaking hands, hooves or tentacles with aliens before 2063 - but failing to inform Earth of the fact until decades after the fact, due to the lightspeed commlag, or even crippling comm range issues.

This would also help explain how only the invention of warp drive deprives civilizations of their virginity as regards interstellar contact: only truly exceptional civilizations come up with devices that can eavesdrop on interstellar communications before the first warp flight.

Our heroes did not indicate in the "Space Seed" teaser that the DY-100 generation of ships had never gone interstellar. All they stated when learning that they were facing a ship of that type was that it must be a "derelict" or in alien hands. This could follow from multiple assumptions, but the heroes don't initially realize this is a sleeper ship, so their one and only assumption might be "fine, so this is one of the early interstellar ships, but since it's been so many centuries, the crew must be dead".

Indeed, given the pronounced lack of surprise, I'd actually assume that the primarily interplanetary DY-100 had indeed been credited with a few interstellar attempts. Perhaps they were all declared failures. Perhaps there were some successes, but none resulted in reports of contact with aliens before 2063. Nobody ever claims there were no crewed interstellar flights at any point before 2063, only that the Charybdis mission of 2037 was a mere "attempt" at leaving Sol.

But if the post-2018 Charybdis is an "attempt", and only the third one, where does that leave the pre-2018 DY-100? Were the two previous attempts/failures made with that tech? (They'd be rather famous cases, then, for their rarity, not easily fitting the "Space Seed" complacency on meeting a DY-100 in deep space.) Or did the older tech remain in use on interstellar sorties after the 2018 propulsion revolution, thus justifying our heroes' lack of surprise?

Or is the lack of surprise at meeting a DY-100 derelict between the stars the result of those ships being used extensively as derelicts in interstellar work? That is, as uncrewed probes, such as the later Woden? Perhaps only post-2018 propulsion warranted attempts at crewed flight, with or without cryosleep.

Timo Saloniemi

Remember what they said in "Space Seed":

SCOTT: Definitely Earth-type mechanism, sir. Twentieth century vessel. Old type atomic power. Bulky, solid. I think they used to call them transistor units. I'd love to tear this baby apart.
MARLA: Captain, it's a sleeper ship.
KIRK: Suspended animation.
MARLA: I've seen old photographs of this. Necessary because of the time involved in space travel until about the year 2018. It took years just to travel from one planet to another.

At the present time it often takes years for a space probe to reach a planet. Thus it is possible that manned interstellar flights in the era of DY-100 class ships were no faster than contemporary interplanetary probes, which is very, very, very slow for interstellar travel.

Of course, if Marla meant that it took just one single year to reach Neptune, the farthest planet in the solar system known at the preset (2019), space ships would be a lot faster than in our 2019. In my post # 654 on page 33 of thread https://www.trekbbs.com/threads/when-did-tos-take-place-23rd-century-or-22nd-century.297786/page-33 I did some calculations of the acceleration capability of DY-100 class ships if they could reach Neptune from Earth in 1 year.

So if it would take the Botany Bay just one single year to travel about 30.33 AU from Earth to Neptune it would travel about 4,537,303,418 kilometers in 31,557,600 seconds, or at an average speed of 143.778 kilometers per second. So the Botany Bay would need to be able to accelerate to a speed of 287.556 kilometers per second and then decelerate for the second half of the voyage for a total delta V of 575.112 Kilometers per second. And then do it again for the return voyage back to Earth. Thus it would need to have a total capacity of velocity change of only 1150.224 kilometers per second.

So possibly DY-100 class ships were built with a capacity for about a total velocity change of 1,200 kilometers per second in each round trip voyage. And suppose that the supermen brought along a light sail to decelerate the Botany Bay when it approached the target star. Then they could have afforded to use all the velocity change ability of the Botany Bay to accelerate to a speed of 1,200 kilometers per second, and then coast to the target star.

At 1,200 kilometers per second for 31,577,600 seconds the Botany Bay would travel only 37,893,120,000 kilometers, or 253.138 AU, in one year. A light year is 63,241.077 AU, so at that speed it would take the Botany Bay 249.82846 years to travel one light year and 2,498.2846 years to travel ten light years.

The fastest velocity implied by the best interpretation of Marla McGver's statement would still be so slow that it would take longer than the 200 to 300 years between Khan's era and Kirk's for a pre-2018 type ship ship to travel to even the closest star system. So there would seem to be no way for such ships to reach another star system before 2063. Someone who wants to claim that there were interstellar contacts made by slow pre-2018 type ships should come up a method for them to exceed by many times the speeds implied by interplanetary voyages taking years, and then explain why that method could not be used within the solar system.

Furthermore:

SPOCK: A strange, violent period in your history. I find no record what so ever of an SS Botany Bay. Captain, the DY-100 class vessel was designed for interplanetary travel only. With simple nuclear-powered engines, star travel was considered impractical at that time. It was ten thousand to one against their making it to another star system. And why no record of the trip?

So Spock seems pretty clear that nobody was recorded as making an attempt at manned interstellar flight before the Botany Bay. And explains why star travel was considered impractical. But the voyage of the Botany Bay became part of recorded history after "Space seed" or at the latest after Khan's rampage in Star trek II: The Wrath of Khan. Certainly before the TNG episode "The Royale" where the Charybdis expedition is mentioned:

PICARD: We have the information you requested. Colonel Stephen Richey was the commanding officer of the explorer ship Charybdis

[Hotel room]

PICARD [OC]: Which had a terrestrial launch date of July 23rd, 2037. It was the third manned attempt to travel beyond the confines of the Earth's solar system.

So the Charybdis expedition was contacted by aliens but never returned any knowledge of that to Earth, and beside the Botany Bay there was only one other manned mission beyond the solar system by 2037, or possible two attempts if for some strange reason the Botany Bay expedition was ignored by Picard. So at that rate there probably weren't very many other manned expeditions beyond the solar system by 2063.

Therefore the idea of interstellar contacts before 2063, even ones that Earth didn't hear about for decades or centuries, seems rather implausible to me.

 

[Henoch]

So the Charybdis expedition was contacted by aliens but never returned any knowledge of that to Earth, and beside the Botany Bay there was only one other manned mission beyond the solar system by 2037, or possible two attempts if for some strange reason the Botany Bay expedition was ignored by Picard. So at that rate there probably weren't very many other manned expeditions beyond the solar system by 2063.

Don't agree. Third expedition means the technology was available for manned interstellar exploration by 2037. I didn't get the opinion that it was a sleeper ship, so, the Charybdis intended to get to another star system and back at a pace that wouldn't require suspended animation. The Charybdis must be FTL in the 2-4 times the speed of light to keep the one way trip to about a year or two, faster (5-10 c) if you want to keep it to months. Reading Richey's diary:

RIKER: Yes. I write this in the hope that it will someday be read by human eyes. I can only surmise at this point, but apparently our exploratory shuttle was contaminated by an alien life form which infected and killed all personnel except myself.​

Richey makes no reference to being spirited away before their shuttle got contaminated. Either the shuttle was visiting a planet surface (à la ENT), or maybe it was visiting an alien space ship, but if the latter, then he would certainly mention it first that he had encountered aliens for the first time in human history. I seems the Charybdis made it to its designation, some planet in another solar system (probably the closest one, Alpha Centauri). Later:

RIKER: Very strange experience. Puzzling. I still can't comprehend how Colonel Richey's vessel could have travelled out that far. Not on it's own, at any rate.
PICARD: Perhaps they were brought here by whoever created that make-believe world down there. It's possible they didn't know how fragile the humans aboard actually were. Only one of them survived.
RIKER: None of it makes any sense.
PICARD: Like Fermat's theorem, it's a puzzle we may never solve.​

So, the aliens brought the entire ship to Theta One Sixteen and put Richey on its planet. If so, then it wasn't the same planet that Richey explored rather another planet far away. That alien life form must be space traveling themselves and brought the Charybdis and Richey along for some reason, maybe to hide the evidence of something they did wrong which caused the death of Richey's crew. It sounds that they could have more easily returned Richey to Earth (only a few light years away), but no, they smuggle him hundreds of light years away, destroy the ship and put Richey in a prison for life! Where's the justice!

Then Earth has 26 more years to launch more missions until warp drive comes around. I would put odds that Earth explored several close star systems (less than 10 light years out) which certainly included Alpha Centauri's tri-system of stars as its first target. Alpha Centauri was probably empty of human-looking aliens (which reenforced that humans are alone in the universe).

TNG suggests World War III put space exploration on pause for a while until Cochrane's first warp flight in ST:FC. Meh.

I guess they could have missed the Vulcans (16 light years out) until Cochrane lit up his warp drive. The Vulcans seemed to be aware of Earth, but didn't want to interfere with its natural development. Warp drive finally got their attention.

In any event, Charybdis must have been FLT before the invention of warp drive.

 

[MAGolding]

The

Don't agree. Third expedition means the technology was available for manned interstellar exploration by 2037. I didn't get the opinion that it was a sleeper ship, so, the Charybdis intended to get to another star system and back at a pace that wouldn't require suspended animation. The Charybdis must be FTL in the 2-4 times the speed of light to keep the one way trip to about a year or two, faster (5-10 c) if you want to keep it to months. Reading Richey's diary:

RIKER: Yes. I write this in the hope that it will someday be read by human eyes. I can only surmise at this point, but apparently our exploratory shuttle was contaminated by an alien life form which infected and killed all personnel except myself.​

Richey makes no reference to being spirited away before their shuttle got contaminated. Either the shuttle was visiting a planet surface (à la ENT), or maybe it was visiting an alien space ship, but if the latter, then he would certainly mention it first that he had encountered aliens for the first time in human history. I seems the Charybdis made it to its designation, some planet in another solar system (probably the closest one, Alpha Centauri). Later:

RIKER: Very strange experience. Puzzling. I still can't comprehend how Colonel Richey's vessel could have travelled out that far. Not on it's own, at any rate.
PICARD: Perhaps they were brought here by whoever created that make-believe world down there. It's possible they didn't know how fragile the humans aboard actually were. Only one of them survived.
RIKER: None of it makes any sense.
PICARD: Like Fermat's theorem, it's a puzzle we may never solve.​

So, the aliens brought the entire ship to Theta One Sixteen and put Richey on its planet. If so, then it wasn't the same planet that Richey explored rather another planet far away. That alien life form must be space traveling themselves and brought the Charybdis and Richey along for some reason, maybe to hide the evidence of something they did wrong which caused the death of Richey's crew. It sounds that they could have more easily returned Richey to Earth (only a few light years away), but no, they smuggle him hundreds of light years away, destroy the ship and put Richey in a prison for life! Where's the justice!

Then Earth has 26 more years to launch more missions until warp drive comes around. I would put odds that Earth explored several close star systems (less than 10 light years out) which certainly included Alpha Centauri's tri-system of stars as its first target. Alpha Centauri was probably empty of human-looking aliens (which reenforced that humans are alone in the universe).

TNG suggests World War III put space exploration on pause for a while until Cochrane's first warp flight in ST:FC. Meh.

I guess they could have missed the Vulcans (16 light years out) until Cochrane lit up his warp drive. The Vulcans seemed to be aware of Earth, but didn't want to interfere with its natural development. Warp drive finally got their attention.

In any event, Charybdis must have been FLT before the invention of warp drive.

There is this quotation from the only entry in the diary left by Colonel Richey the commander of the Charybdis:

RIKER: Obviously made by Colonel Richey.
PICARD [OC]: Can you read it?
RIKER: Yes. I write this in the hope that it will someday be read by human eyes. I can only surmise at this point, but apparently our exploratory shuttle was contaminated by an alien life form which infected and killed all personnel except myself.

[Bridge]

RIKER [OC]: I awakened to find myself here in the Royale Hotel, precisely as described in the novel I found in my room.

[Hotel room]

RIKER: And for the last thirty eight years I have survived here. I have come to understand that the alien contaminators created this place for me out of some sense of guilt, presuming that the novel we had on board the shuttle about the Hotel Royale was in fact a guide to our preferred lifestyle and social habits. Obviously, they thought this was the world from which I came.

[Bridge]

RIKER [OC]: I hold no malice toward my benefactors. They could not possibly know the hell they have put me through.

[Hotel room]

RIKER: for it was such a badly written book, filled with endless clich� and shallow characters. I shall welcome death when it comes.

There are two possible interpretations:

That the entire crew left the Charybdis in a shuttle perhaps to land on an alien world, and that Richey lost consciousness as a result of alien interaction, and awoke in the hotel room constructed for him by the aliens with data from the novel.

or:

That the "shuttle" mentioned by Richey was the Charybdis where the entire crew was in suspended animation and the alien interaction apparently killed all the crew except for Richey, who awoke from his original suspended animation in the hotel room constructed for him by the aliens with data from the novel.

I always believed in latter interpretation and thus that it was quite possible that the Charybdis was STL.

Note that if the Charybdis had a FTL drive that was not warp drive, it could have been impulse drive, meaning that the valiant could have left Earth before 2063 and 200 years before TOS, meaning TOS could be less than 200 years after 2063.

 

[Henoch]

That the "shuttle" mentioned by Richey was the Charybdis where the entire crew was in suspended animation and the alien interaction apparently killed all the crew except for Richey, who awoke from his original suspended animation in the hotel room constructed for him by the aliens with data from the novel.

Sounds reasonable, but you must embrace that Earth returned to using sleeper ships, again. I could go either way. Is there any definitive evidence from any of the series that this occurred?

 

[Timo]

As regards Richey's shuttle foray, the fragments of evidence we hear allow for the ship to be intercepted when it's on its way to some mundane off-Sol destination, say, a dwarf planet, or to a neighboring star system it is only expected to reach decades later - then delivered to Theta 116 - and then the intrepid astronauts get to have a look around in their shuttle, and all but one perish. No need for the ship to reach any intended destination, either at all, or within any specific timespan.

Cryosleep isn't ruled out for Charybdis: the 2018 propulsion revolution would outdate it in interplanetary flight, but some type of "stasis" remains in interstellar use in 2210 still, as per Kim's story in "11:59". And even if cryosleep is a lost art in the 2260s, as in ST:ID and perhaps "Space Seed", it would still be a mastered skill in the 2030s.

Kim: "It was around 2210. My uncle Jack was on a deep space mission to Beta Capricus."
Paris: "That's when deep space meant the next star over."
Kim: "And that was when they still had to go into stasis. So, Jack put his crew under as soon as they left orbit, and piloted the ship by himself for six months."

We know the 1990s tech works for centuries if needed (although folks back then might not have been so trusting). We know the 2370s stasis tech is reliable for a month and has been used for "much longer" stretches of time (VOY "One"). The nature and performance of the 2030s or 2210s tech is up to debate, but its existence seems like a safe bet. So as the Charybdis would be going to "the next star over" at the very best, it's quite possible that stasis would allow Richey to make it there alive. Although probably not before Cochrane or one of his disciples sped past him!

The fact that Spock adamantly labels the DY-100 interplanetary yet the heroes initially aren't all that surprised to find one between the stars is a contradiction unless we go the route of saying that crewed flights were strictly interplanetary - that the engines would have been up to it, but that either the travel times or then the unpredictable risks would have spelled death to any crews. Or unless we decide that DY-100 ships launched later than the 1990s that Spock is concerned with would be valid for interstellar missions, crewed or otherwise. Spock does say only that the last DY-100 was built centuries ago, not that the type would have ceased to serve at some specific timepoint.

Timo Saloniemi

 

[Henoch]

Cryosleep isn't ruled out for Charybdis: the 2018 propulsion revolution would outdate it in interplanetary flight, but some type of "stasis" remains in interstellar use in 2210 still, as per Kim's story in "11:59". And even if cryosleep is a lost art in the 2260s, as in ST:ID and perhaps "Space Seed", it would still be a mastered skill in the 2030s.

Timo on the spot. Thanks for locating evidence per request. It's a shame that the NX-01 project failed back in the 2150's.

From Memory Alpha:

Kim is telling about his uncle Jack, who commanded a mission to Beta Capricus in 2210, a deep space mission at that time. The journey took six months and his uncle piloted the spacecraft the entire time – the rest of the crew was in stasis. When he arrived it turned out that Beta Capricus did not exist, but was indeed just the misinterpreted image of a distant galaxy. Jack did not wake his crew because there was nothing to do or see and returned to Earth. When they arrived six months later, Jack brought the crew out of stasis and they wondered why they hadn't left Earth's orbit.​

Based on this info, it would not be a stretch to also assume that the SS Columbia circa 2236 could have been a sleeper ship, too.

 

[Tenacity]

TNG suggests World War III put space exploration on pause for a while until Cochrane's first warp flight in ST:FC

Where did you find this suggestion?

 

[Henoch]

Where did you find this suggestion?

ST:FC, where we find Earth living like survivors of a holocaust in the backwoods of Montana, TNG post-holocaust courts with Judge Qudy, etc.

By the way, I'm very malleable when good evidence is provided, so, if you have the goods, I'm ready to learn.

 

[MAGolding]

Sounds reasonable, but you must embrace that Earth returned to using sleeper ships, again. I could go either way. Is there any definitive evidence from any of the series that this occurred?

Earth would no longer need sleeper ships for manned interplanetary travel 2018, but might still need them for manned interstellar travel, or even travel to the outermost parts of the solar system like the outer cometary halo.

And see Timo's answer number 71 above for examples of use of suspended animation or similar tech in later voyages.

In TNG "The Emissary" a Klingon ship T'Ong is approaching Federation colonies:

K'EHLEYR: Haven't changed a bit. Well, I missed you, too. Two days ago, Starbase Three Three Six received an automated transmission from a Klingon ship, the T'Ong. That ship was sent out over seventy five years ago.
RIKER: When the Federation and the Klingon Empire were still at war.
K'EHLEYR: The message was directed to the Klingon High Command. It said only that the ship was returning home and was about to reach its awakening point.
PICARD: Which suggests that the crew had been in cryogenic sleep for that long journey.
K'EHLEYR: Exactly.

 

[BK613]

The website Atomic Rockets (which sounds down right flaky but it isn't) has a list of the actual formulae for figuring out relativistic velocities and times and things (need to scroll a bit).
Two that would be applicable here are the one for distance traveled and final velocity (both expressed from Earth's frame of reference.)
d = (c^2/a) (Sqrt[1 + (a*t/c)^2] - 1) (given acceleration and Earth time)
v = (a*t) / Sqrt[1 + (a*t/c)^2] (given acceleration and Earth time)

where

• a = acceleration (m/s2) remember that 1 g = 9.81 m/s2
• t = time experienced non-accelerating frame of reference in which they started (e.g., Earth) (s)
• d = distance covered as measured in Earth's frame of reference (m)
• v = final speed as measured in Earth's frame of reference (m/s)
• c = speed of light in a vacuum = 3e8 m/s

They also recommend, for convenience, to express "t in years, distance in light-years, c = 1 lyr/yr, and 1 g = 1.03 lyr/yr^2"
Doing so yields the following results: A year of 1g acceleration will result in a distance traveled of 0.42 ly and a final velocity of 0.717c
Coasting after that for 1 year will carry you another 0.717 ly ( + 0.42 = 1.127 total)
Coasting after that for 2 years will carry you another 1.435 ly (1.855 total)
Coasting after that for 5 years will carry you another 3.59 ly (4.01 total)
Coasting after that for 10 years will carry you another 7.175 ly (7.595 total)
Coasting after that for 199 years will carry you another 142.78 ly (143.20 total)
Coasting after that for 299 years will carry you another 214.53 ly (214.95 total)

 

[StarCruiser]

Still have to allow for the braking phase - which, in theory, is the reverse of the first part...

Then, you need to know the required mass of the fuel needed for that run (plus a margin of reserves) and the efficiency (specific impulse) of the drive used, the mass of the payload, the ship and, and ...?!?

 

[BK613]

Still have to allow for the braking phase - which, in theory, is the reverse of the first part...

I started to include that as well, but had begun the list with the last two (so the Botany Bay as found was foremost on my mind.)

Then, you need to know the required mass of the fuel needed for that run (plus a margin of reserves) and the efficiency (specific impulse) of the drive used, the mass of the payload, the ship and, and ...?!?

Of course but the implicit caveat of my post is that you can (do 1 g for a year) and if you can, pushing one kg or a million kg won't change the velocity or distance outcomes.

 

[Timo]

The trick here is to keep the acceleration so low that interplanetary trips still take "years". One gee is probably way too much, as the ships in all likelihood wouldn't be derided for their inability to reach Pluto in a shorter time, but for the need to spend years on a run to supply the mines on Jupiter's moons.

On the other hand, constant thrust throughout the interplanetary trip would be preferable, to allow for the interstellar performance we see. This is already impressive supertech, unless we assume truly minimal accelerations attainable by currently known electric thrusters and whatnot. And once we get that out of the way, we can stop worrying about the rocket equation, which thanks to X no longer applies. Is X gravity manipulation? Subspace fields? Propellantless propulsion of some other sort? Ability to get propellant from interplanetary space? Possibilities certainly exist in Trek.

Timo Saloniemi

 

[Mytran]

The trouble is, the lines about interplanetary travel taking "years" is really incompatible with the BB ending up light years from Earth just 270 years after launch.
Even if we use Pluto as an extreme example and say that it takes 2 years to get there from Earth, that's still "only" 4.8 billion KM from the sun.
I used this website https://www.omnicalculator.com/physics/acceleration to calculate the rate of acceleration, assuming they accelerate constantly until they reach their destination (obviously this would not be the case, since time would be needed to decelerate.

Acceleration works out at 0.00241 m/s^2

At constant acceleration, after 270 years they would have travelled 8,748,276,6693,568 KM or 9.25 light years
At constant acceleration, after 270 years they would have achieved 3.43% of lightspeed or 0.0342592c which BTW is nowhere near to experience enough time dilation to justify Kirk's statement that Khan had been sleeping for 2 centuries.