Maneuver Trumps Jump drive in system

[Arkathan]

Tytalan, you already HAVE the instances in which M-drive works better, and since in every post, I concede that there are many cases M-Drive is better, the only examples I NEED to provide are the ones offering the other side of the coin.
My comments are in response to yours being decidedly one-sided, and not just towards my posts, and then moving the goal post when presented with contradictory material.
In every post, I say sometimes you ARE right, but sometimes you are not.
And I didn't say you were Truman, I said that the same mindset drove Truman to find a use for his new atomic hammer.

Concerning the DSMS, you proposed that, but if you take it away, the two ships above cost the same. Which then becomes a question of flexibility and function. I guarantee that a company spending that much is going to choose the J1M1, in order to be able to get goods to and from nearby systems when needed - in those cases where the two ships would arrive at nearly the same time.
For shorter distances, you have to do a cost analysis over whether a REALLY cheap show boat is preferable. Can the facility produce enough material to fill a cargo hold in a week or two weeks? For that matter, is the system secure? Can a rail gun sling the product towards the planet and rely on a slow boat with a cargo net/scoop and interplanetary Hauler net to go around catching the artificial asteroids of goodness?
Bottom line, it is a complex equation, and the fastest bestest isn't always going to be the optimal solution.

 

[phavoc]

I have never liked the idea of the deep space drive. It seems rather pointless and a retcon into something that is neither warranted or makes much sense.

The discussion also has to be version-based. As in which particular version of Traveller are you wanting to use as a comparison. This is a MGT board, but not all discussions are MGTv2 based.

All in all, for nearly all intra-system travel M-drives seem the best option (tossing out the deep space drive altogether) as it's a simple issue of accelerate, turn-over and decelerate. You don't need to install the J-drive or set aside space for the j-drive tankage.

I think we also may be overestimating the premium people will pay for time as well. Nearly all cargo is going to be non-perishable and cost-per-ton for transport will dictate which type of drive is used. It's the same arguments that have dictated merchant traffic since the invention of transport systems. Merchants want cheap over speed - with few exceptions. This holds true in modern times as well as we see with container transport. The 30kt container ships that were placed on the trans-atlantic passages were all retired as too expensive to operate. The fact that you shaved a few days off the transit time was not enough to justify the added expenses.

Passengers are slightly different, though. There are those who will pay for speed (as evidenced by clipper ships in the age of sail, the first passenger aircraft flying across the oceans vs taking a ship, and the now-retired Concorde). But the vast majority of people are content with comfort and cost vs high costs.

If we continue this extrapolation I think we'd find something similar in the future since there don't appear to be lots of changes in the Traveller universe aside from higher technology levels. Cost and comfort will be prized over absolute speed for most people.

 

[Terry Mixon]

I have never liked the idea of the deep space drive. It seems rather pointless and a retcon into something that is neither warranted or makes much sense.

The discussion also has to be version-based. As in which particular version of Traveller are you wanting to use as a comparison. This is a MGT board, but not all discussions are MGTv2 based.

All in all, for nearly all intra-system travel M-drives seem the best option (tossing out the deep space drive altogether) as it's a simple issue of accelerate, turn-over and decelerate. You don't need to install the J-drive or set aside space for the j-drive tankage.

I think we also may be overestimating the premium people will pay for time as well. Nearly all cargo is going to be non-perishable and cost-per-ton for transport will dictate which type of drive is used. It's the same arguments that have dictated merchant traffic since the invention of transport systems. Merchants want cheap over speed - with few exceptions. This holds true in modern times as well as we see with container transport. The 30kt container ships that were placed on the trans-atlantic passages were all retired as too expensive to operate. The fact that you shaved a few days off the transit time was not enough to justify the added expenses.

Passengers are slightly different, though. There are those who will pay for speed (as evidenced by clipper ships in the age of sail, the first passenger aircraft flying across the oceans vs taking a ship, and the now-retired Concorde). But the vast majority of people are content with comfort and cost vs high costs.

If we continue this extrapolation I think we'd find something similar in the future since there don't appear to be lots of changes in the Traveller universe aside from higher technology levels. Cost and comfort will be prized over absolute speed for most people.

Also, a bit of science that might have been overlooked when they sprang the idea of needing a deep space drive for things outside the 1000D is that all of Charted Space--including the deep rifts--is inside the 1000D limit of the galactic core and bulge gravitationally (it has 1/5 of the mass of our galaxy). That means it really is unnecessary as the maneuver drives will work just fine.

 

[WHULorigan]

Also, a bit of science that might have been overlooked when they sprang the idea of needing a deep space drive for things outside the 1000D is that all of Charted Space--including the deep rifts--is inside the 1000D limit of the galactic core and bulge gravitationally (it has 1/5 of the mass of our galaxy). That means it really is unnecessary as the maneuver drives will work just fine.

The idea was that it is based on 1000D from the specific source of gravitation. So each of the stars in the Core serves as the center of a 1000D surface/volume. Now if those individual center-of-mass sources overlap their 1000D limits in such a way as you describe, then yes. But I doubt it.

I suppose if you wanted to extrapolate and calculate it as a specified threshhold g-value or tidal-force value, you could do that and see how far out the "envelope" would extend (remembering to take into account the centrifugal pseudo-force of the accelerated reference frame of the rotating galaxy, which would lessen the net g-value).


The 1000D limit is a legacy idea going back to T4 & T5 primarily to ensure that every space pilot doesn't have an unlimited-acceleration extinction-level event world-impactor at his disposal (which is what one effectively had with the MT "Unlimited-range-but-for-power-plant-fuel" Thruster-plate). Otherwise, governments would limit the availability of the technology.

 

[phavoc]

The idea was that it is based on 1000D from the specific source of gravitation. So each of the stars in the Core serves as the center of a 1000D surface/volume. Now if those individual center-of-mass sources overlap their 1000D limits in such a way as you describe, then yes. But I doubt it.

I suppose if you wanted to extrapolate and calculate it as a specified threshhold g-value or tidal-force value, you could do that and see how far out the "envelope" would extend (remembering to take into account the centrifugal pseudo-force of the accelerated reference frame of the rotating galaxy, which would lessen the net g-value).


The 1000D limit is a legacy idea going back to T4 & T5 primarily to ensure that every space pilot doesn't have an unlimited-acceleration extinction-level event world-impactor at his disposal (which is what one effectively had with the MT "Unlimited-range-but-for-power-plant-fuel" Thruster-plate). Otherwise, governments would limit the availability of the technology.

If that was the intent then they missed their mark. As far as I know, Mark's article on ships retaining their speed and heading when entering/leaving jump space has remained canon across all editions. If that is the case then the ship could accelerate to the 1000D limit, jump, enter at the 100D planetary limit with more than enough speed to cause an extinction-level event. And, if you didn't want to lose your ship, all it would have to do is separate itself from a carried object that has sufficient mass, use it's M-drives to alter the ships heading slightly and the carried object will smack into the planet and the ship will not. Of course, if you are destroying a planetary biosphere I don't think anyone is going to be too concerned with getting their ship back. Easy enough to have a parasite ship to peel off and meet up at a rendezvous for transport out of the system - not like any ship in the locale is going to have the acceleration to catch it.

 

[Terry Mixon]

The idea was that it is based on 1000D from the specific source of gravitation. So each of the stars in the Core serves as the center of a 1000D surface/volume. Now if those individual center-of-mass sources overlap their 1000D limits in such a way as you describe, then yes. But I doubt it.

Well, the galactic core has ten million stars within one parsec of Sagittarius A*. Seems like that would count. Add in the galactic bulge and there are a lot of stars packed into a pretty tight area.

Also, if it were strictly diameter, one could jump in and out of the area right beside a black hole. A singularity has no diameter at all.

I suppose if you wanted to extrapolate and calculate it as a specified threshhold g-value or tidal-force value, you could do that and see how far out the "envelope" would extend (remembering to take into account the centrifugal pseudo-force of the accelerated reference frame of the rotating galaxy, which would lessen the net g-value).


The 1000D limit is a legacy idea going back to T4 & T5 primarily to ensure that every space pilot doesn't have an unlimited-acceleration extinction-level event world-impactor at his disposal (which is what one effectively had with the MT "Unlimited-range-but-for-power-plant-fuel" Thruster-plate). Otherwise, governments would limit the availability of the technology.

My personal view is that it has to be related to gravitational strength and mass.

 

[Arkathan]

If that was the intent then they missed their mark. As far as I know, Mark's article on ships retaining their speed and heading when entering/leaving jump space has remained canon across all editions. If that is the case then the ship could accelerate to the 1000D limit, jump, enter at the 100D planetary limit with more than enough speed to cause an extinction-level event. And, if you didn't want to lose your ship, all it would have to do is separate itself from a carried object that has sufficient mass, use it's M-drives to alter the ships heading slightly and the carried object will smack into the planet and the ship will not. Of course, if you are destroying a planetary biosphere I don't think anyone is going to be too concerned with getting their ship back. Easy enough to have a parasite ship to peel off and meet up at a rendezvous for transport out of the system - not like any ship in the locale is going to have the acceleration to catch it.

Jump 4 and 24 weeks of fuel, a jump net filled with 10k tons of rocks, accellerate to the 1000D limit in the first system, 2x the 1000D in the second and 1000D + whatever distance to the planet past the primary in the third. Release the net and miss the planet, and jump out.

The 1000D limit is useless.

 

[WHULorigan]

If that was the intent then they missed their mark. As far as I know, Mark's article on ships retaining their speed and heading when entering/leaving jump space has remained canon across all editions. If that is the case then the ship could accelerate to the 1000D limit, jump, enter at the 100D planetary limit with more than enough speed to cause an extinction-level event.

Yes, it has been discussed before. But if you want the "impactor" to not be interceptable by a system defense system, you need to do several passes thru the 1000D limit edge to edge (or do it in another system) and then jump, and hope nobody observes you and figures out what you are doing.

 

[WHULorigan]

Well, the galactic core has ten million stars within one parsec of Sagittarius A*. Seems like that would count. Add in the galactic bulge and there are a lot of stars packed into a pretty tight area.

Also, if it were strictly diameter, one could jump in and out of the area right beside a black hole. A singularity has no diameter at all.

There are rules for Degenerate Dwarfs, Neutron Stars, and Black Holes in MgT: The Great Rift for Jump Drives (it's not 100D). I assume M-Drives would be similar.

My personal view is that it has to be related to gravitational strength and mass.

So do I. I don't mind the cut-off, but I don' t like 1000D; I think that is too short (at least for a complete fall-off to x0.01). In T4 there was a typo/erratum (I presume) in one of the books that said 2000AU, whereas it likely should have said 2000 radii. But I think the erratum is a good extreme max cut-off value ironically for at least decent drive performance, even if not full performance (perhaps 1 or maybe 2 more moderate threshholds before x0.01is reached @ 1000-2000AU and beyond into Deep Space).

 

[phavoc]

Jump 4 and 24 weeks of fuel, a jump net filled with 10k tons of rocks, accellerate to the 1000D limit in the first system, 2x the 1000D in the second and 1000D + whatever distance to the planet past the primary in the third. Release the net and miss the planet, and jump out.

The 1000D limit is useless.

That assumes the systems are in alignment and your course through a system does not take you planetary objects. If we use the Miller article then your straight line acceleration parameters are going to make for some hella course corrections - assuming you have the time to do so. And for all that acceleration you have to spend an equal amount to time decelerating when you get to a safe system.

10k dton of rocks seems odd though. A purpose-built penetrator with mass to it (collapsed matter spears would work) would do better than rocks - it has more mass and would be a smaller object to detect and intercept - especially if you applied a RAM coating on it to counter radar. Using parasite delivery vehicles would also allow you to engage other targets or orbital constructs.

Basically if you wanna slag a world there is nothing stopping you - except that the enemy will always have at least one ship of their own with which to slag yours. MAD does wonders, except in sci-fi games were everyone is rather bloodthirsty in their tactics.

 

[J. L. Brown]

That assumes the systems are in alignment and your course through a system does not take you planetary objects. If we use the Miller article then your straight line acceleration parameters are going to make for some hella course corrections - assuming you have the time to do so. And for all that acceleration you have to spend an equal amount to time decelerating when you get to a safe system.

10k dton of rocks seems odd though. A purpose-built penetrator with mass to it (collapsed matter spears would work) would do better than rocks - it has more mass and would be a smaller object to detect and intercept - especially if you applied a RAM coating on it to counter radar. Using parasite delivery vehicles would also allow you to engage other targets or orbital constructs.

Basically if you wanna slag a world there is nothing stopping you - except that the enemy will always have at least one ship of their own with which to slag yours. MAD does wonders, except in sci-fi games were everyone is rather bloodthirsty in their tactics.

So slag a planet while posing as someone else. Instead of one ship jumping to several intermediate systems, pick just one suitable pre-target system within jump range of the target & do 17 jump & accelerate cycles there before jumping to the target. Or before sending jump-torpedoes to the target -- if you launch 10000 planet-killers, who cares if 99% of them mis-jump & miss?

This is a place where 'Can I slag a planet?' is always going to be 'Yes; easily -- now, do I want to deal with all the fallout & consequences of slagging this planet?' Honestly, it is a little annoying that the 'best' answer that Traveller authors could devise for murder-hobos was 'The universe does not work that way'. The only thing that does is force the murder-hobos to look for other tools to commit atrocities.

 

[Arkathan]

That assumes the systems are in alignment and your course through a system does not take you planetary objects. If we use the Miller article then your straight line acceleration parameters are going to make for some hella course corrections - assuming you have the time to do so. And for all that acceleration you have to spend an equal amount to time decelerating when you get to a safe system.

10k dton of rocks seems odd though. A purpose-built penetrator with mass to it (collapsed matter spears would work) would do better than rocks - it has more mass and would be a smaller object to detect and intercept - especially if you applied a RAM coating on it to counter radar. Using parasite delivery vehicles would also allow you to engage other targets or orbital constructs.

Basically if you wanna slag a world there is nothing stopping you - except that the enemy will always have at least one ship of their own with which to slag yours. MAD does wonders, except in sci-fi games were everyone is rather bloodthirsty in their tactics.

The Astrogator simply adjusts the entry point for each jump so that velocity is conserved in the direction of the planet. You calculate the optimal angle to enter the target system and head in that direction. Plot your first jump to come out where your vector will take you across the widest possible part of the system. On the final jump, come out on course for the planet.
The rocks were just an illustration of how easy it could be. The jump net will keep them together until they hit atmosphere, so scattering is minimal. Naturally, putting more money into the impactor will optimize results.
It wasn't a blueprint, so much as a repudiation of the alleged reasoning for the 1000D limit.

 

[WHULorigan]

So slag a planet while posing as someone else. Instead of one ship jumping to several intermediate systems, pick just one suitable pre-target system within jump range of the target & do 17 jump & accelerate cycles there before jumping to the target. Or before sending jump-torpedoes to the target -- if you launch 10000 planet-killers, who cares if 99% of them mis-jump & miss?

Yes, but keep in mind that it will take time to do this pre-acceleration in the initiating system, which will give time for someone to notice - and it should be fairly obvious what they are doing: building up a significant momentum vector (either friendly authorities in the system, or "spies" in the system who watch for such things from a likely hostile power). And calculating a likely potential target from the vectors shouldn't be difficult.

 

[Arkathan]

Yes, but keep in mind that it will take time to do this pre-acceleration in the initiating system, which will give time for someone to notice - and it should be fairly obvious what they are doing: building up a significant momentum vector (either friendly authorities in the system, or "spies" in the system who watch for such things from a likely hostile power). And calculating a likely potential target from the vectors shouldn't be difficult.

The Traveller Map designates numerous systems as binary. Lots of the companions are unpopulated. A lonely tree in the woods clapping with one hand.

 

[WHULorigan]

The Traveller Map designates numerous systems as binary. Lots of the companions are unpopulated. A lonely tree in the woods clapping with one hand.

For a Far Binary in the Remote System, yes. My guess would be that such systems would maintain patrols there, though, unless their system-squadrons are severely under-budgeted. Those are prime haunts for invasion-forces, forward hostile bases, or piracy-havens.

 

[Condottiere]

Maybe an automated mass driver in orbit, that chucks a large ball bearing in front of a fast moving object heading for a planetary collision.

 

[phavoc]

So slag a planet while posing as someone else. Instead of one ship jumping to several intermediate systems, pick just one suitable pre-target system within jump range of the target & do 17 jump & accelerate cycles there before jumping to the target. Or before sending jump-torpedoes to the target -- if you launch 10000 planet-killers, who cares if 99% of them mis-jump & miss?

This is a place where 'Can I slag a planet?' is always going to be 'Yes; easily -- now, do I want to deal with all the fallout & consequences of slagging this planet?' Honestly, it is a little annoying that the 'best' answer that Traveller authors could devise for murder-hobos was 'The universe does not work that way'. The only thing that does is force the murder-hobos to look for other tools to commit atrocities.

I get it, but false flag operations like that exist more in Tom Clancy novels than reality. Almost always the people who are set on mass murder WANT everyone to know it was them who did it. We've not (yet) had terrorists get their hands on nuclear weapons, and obviously starships slinging fractional-C objects at planets as poor-mans nukes will be more easily available in the far future.

I just see it as unlikely. And, of course, the first time it occurs you'll start seeing those planets that can afford it to deploy defenses and better detection gear to make it difficult, at best, to do it again. So far history tells us that the types of groups willing to mass murder are quite uncommon (not the ones that SAY it, but the ones that actually are capable of, and willing, to carry it out).

 

[phavoc]

The Astrogator simply adjusts the entry point for each jump so that velocity is conserved in the direction of the planet. You calculate the optimal angle to enter the target system and head in that direction. Plot your first jump to come out where your vector will take you across the widest possible part of the system. On the final jump, come out on course for the planet.
The rocks were just an illustration of how easy it could be. The jump net will keep them together until they hit atmosphere, so scattering is minimal. Naturally, putting more money into the impactor will optimize results.
It wasn't a blueprint, so much as a repudiation of the alleged reasoning for the 1000D limit.

This is where I think it gets difficult to do this. A small half-degree course adjustment in the outer system will cause a very large deviation in your vector, and to bring it back online will require a lot of delta-V. The objects you launch will retain your speed and vector (unpowered ones won't). The farther you travel the greater your deviation.

This assumes that Traveller jumps are literally straight-lines from exit in your departure system to entry in your arrival system. A star system is huge, especially if you are considering a 1000D from the central star. Staying well above/below the plane of the ecliptic will give you plenty of room to maneuver, and you'll be well away from nearly all traffic since there is no point for ships to be there since there is nothing for them to be there for. According to Mark, when you jump you retain the angular velocity of the system you were in, along with your vector and your own velocity. This can make for some complicated navigation as you jump through multiple systems (which I think is overkill).

Yes, rocks would be easy to find, easy to assemble, and don't emit any electronic signature. Coming in from above/below the planet the odds of them being detected in time to do anything are slim - though according to the same book that gave us the deep space drive, we also have the gravitic detector that CAN detect the entry of your ship along with the rocks you wanna through - though it's "limited" to light-speed reporting. Assuming you are moving at .1C, that still gives the detection system enough time to detect and possibly intercept objects tossed your way. In fact, at least according to the system as explained, it can see light years out from it's position. Depending on where you place your detectors you could literally back-track the ship to it's origin.

None of that is insurmountable from a planning perspective if your design is to throw suspicion elsewhere, but it does leave a possible trail to follow. Personally the grav detector and deep space drive don't belong in the Traveller universe in my opinion. They fundamentally alter a lot of the material that pokes too many logical holes in things. Not to say that they couldn't come about, but the rules don't take them into account, so I don't think they should be there.

 

[Arkathan]

This is where I think it gets difficult to do this. A small half-degree course adjustment in the outer system will cause a very large deviation in your vector, and to bring it back online will require a lot of delta-V. The objects you launch will retain your speed and vector (unpowered ones won't). The farther you travel the greater your deviation.

This assumes that Traveller jumps are literally straight-lines from exit in your departure system to entry in your arrival system. A star system is huge, especially if you are considering a 1000D from the central star. Staying well above/below the plane of the ecliptic will give you plenty of room to maneuver, and you'll be well away from nearly all traffic since there is no point for ships to be there since there is nothing for them to be there for. According to Mark, when you jump you retain the angular velocity of the system you were in, along with your vector and your own velocity. This can make for some complicated navigation as you jump through multiple systems (which I think is overkill).

Yes, rocks would be easy to find, easy to assemble, and don't emit any electronic signature. Coming in from above/below the planet the odds of them being detected in time to do anything are slim - though according to the same book that gave us the deep space drive, we also have the gravitic detector that CAN detect the entry of your ship along with the rocks you wanna through - though it's "limited" to light-speed reporting. Assuming you are moving at .1C, that still gives the detection system enough time to detect and possibly intercept objects tossed your way. In fact, at least according to the system as explained, it can see light years out from it's position. Depending on where you place your detectors you could literally back-track the ship to it's origin.

None of that is insurmountable from a planning perspective if your design is to throw suspicion elsewhere, but it does leave a possible trail to follow. Personally the grav detector and deep space drive don't belong in the Traveller universe in my opinion. They fundamentally alter a lot of the material that pokes too many logical holes in things. Not to say that they couldn't come about, but the rules don't take them into account, so I don't think they should be there.

The last sentence of my post is the most relevant.
No one will ever convince me that that rule is not stupid.

 

[J. L. Brown]

For a Far Binary in the Remote System, yes. My guess would be that such systems would maintain patrols there, though, unless their system-squadrons are severely under-budgeted. Those are prime haunts for invasion-forces, forward hostile bases, or piracy-havens.

That runs smack into the published canon fleets. The entire Trojan Reach Fleet has about 30 ships.