Experimenting with Hop Drive

[whulorigan]

No, not quite.

Hop-1 is a TL-17 technology, right?
Stage Experimental is three TLs earlier, right?
So, Exp Hop-1 is a TL-14 technology.
At TL-14 we can't get above Hop-1, regardless of how powerful drive we use.

The table only covers this case:
A Std drive-E in a 1000 Dt hull is potential 1.
An Exp Hop drive-E is potential 1×50% = 0.5, rounded to 0.

The table only covers a few pre-calculated cases, not every combination of drive, stage, and hull:
Use a bigger drive, get a higher potential, limited to 1 by TL and stage.

I think the point Spank is referencing is the Table J on p. 127 of T5.10 Book 2.

The footnote on the Table says:

Shows Jump Potential based on TL Stage Effects.
Parenthetic is Drive Potential (Std J-1 has Drive Potential-1).

Higher order drives experience TL Stage Effects like Jump but at higher Tech Levels.

Jump-0. Jump Drives with Jump Potential less than 1 can achieve Jump exactly equal to potential times 1 parsec (Jump 0.5 achieves exactly 0.5 parsecs; Jump 0.8 achieves exactly 0.8 parsecs).

Presumably this means that for Hop-0: Hop 0.5 achieves exactly (10.0 x 0.5) = 5pc @ TL14 (coincidentally, the exact same thing that Standard Jump-5 does @ TL14).

 

[AnotherDilbert]

Presumably this means that for Hop-0: Hop 0.5 achieves exactly (10.0 x 0.5) = 5pc @ TL14 ...

Yees, agreed.

... (coincidentally, the exact same thing that Standard Jump-5 does @ TL14).

It's T5, it's not that simple...

As an Experimental drive, it has no governor, so only Hop 0.5±10%, and as a Hop drive, no microjumps.
So, it can only do 4.5-5.5 Pc.
Unless of course it you aim for a gravity well that kicks you back into normal space short of 5 Pc.

 

[whulorigan]

Yees, agreed.


It's T5, it's not that simple...

As an Experimental drive, it has no governor, so only Hop 0.5±10%, and as a Hop drive, no microjumps.
So, it can only do 4.5-5.5 Pc.
Unless of course it you aim for a gravity well that kicks you back into normal space short of 5 Pc.

Well yes. But anything less than Hop-1 (i.e. a "Hop-0") is a microhop . . .
And without the Hop-governor it can only do 4.5-5.5 pc

Unless of course it you aim for a gravity well that kicks you back into normal space short of 5 Pc.

Which seems to be a Standard Operating Procedure for Hop-Drives anyway, if you want to use them for less than Hop-1 ( ≤ 9.0 pc) and you don't want to carry a secondary Jump Drive, according to rules elsewhere, which actually makes this "Hop-0" provision for pre-Standard Drives confusing. ISTR that elsewhere in the text concerning the Higher-Order FTL Drives that it notes that they cannot be used to produce a "transition" of equal to or less than the maximum of the prior order magnitude drive. So that a Standard-Hop-1 minimally produces a "Hop" of greater than 9pc (unless you aim to "shoot thru" a gravity well and force-precipitate out short of the plot destination.

Can a mature Standard-Hop-1 (or greater) Drive (with Hop-Governor) produce a controlled and precision "Hop-0" (i.e. Jump 1-9, or even Jump 5-9)? I certainly prefer this interpretation, to be honest.

(I also like to think that there is a minimum "microjump" or "Jump-0" distance beyond which you cannot go based on some type of Uncertainty Principle or other, but that the distance is so small in-system (hundreds of thousands or millions of kilometers) that it is not normally talked about in practical circles save by academics and theorists, as it would usually be quicker to use M-Drives over such a distance anyway.)

 

[AnotherDilbert]

Well yes. But anything less than Hop-1 (i.e. a "Hop-0") is a microhop . . .

Sadly, no:

B2, p116:
_ _ Micro-Jump. A micro-jump is the use of Jump Drive to travel a distance of less than one parsec. A jump within a star system is a micro-jump. The jump still lasts seven days, but the distance travelled is restricted to within the system. The jumpline may not intersect any 100D spheres.
_ _ A micro-jump is possible only with a Jump Drive.

Which seems to be a Standard Operating Procedure for Hop-Drives anyway, ...

Agreed.

... if you want to use them for less than Hop-1 ( ≤ 9.0 pc) and you don't want to carry a secondary Jump Drive, according to rules elsewhere, which actually makes this "Hop-0" provision for pre-Standard Drives confusing.

Unless you are very sure about you ability to master astrogation, you really need a secondary jump drive to get the last few Pc you missed.

Can a mature Standard-Hop-1 (or greater) Drive (with Hop-Governor) produce a controlled and precision "Hop-0" (i.e. Jump 1-9, or even Jump 5-9)? I certainly prefer this interpretation, to be honest.

Given how confused p116 is, I think you can choose more or less any interpretation, and even claim it's RAW (-ish)

 

[Krikkitone]

Well yes. But anything less than Hop-1 (i.e. a "Hop-0") is a microhop . . .
And without the Hop-governor it can only do 4.5-5.5 pc




Which seems to be a Standard Operating Procedure for Hop-Drives anyway, if you want to use them for less than Hop-1 ( ≤ 9.0 pc) and you don't want to carry a secondary Jump Drive, according to rules elsewhere, which actually makes this "Hop-0" provision for pre-Standard Drives confusing. ISTR that elsewhere in the text concerning the Higher-Order FTL Drives that it notes that they cannot be used to produce a "transition" of equal to or less than the maximum of the prior order magnitude drive. So that a Standard-Hop-1 minimally produces a "Hop" of greater than 9pc (unless you aim to "shoot thru" a gravity well and force-precipitate out short of the plot destination.

Can a mature Standard-Hop-1 (or greater) Drive (with Hop-Governor) produce a controlled and precision "Hop-0" (i.e. Jump 1-9, or even Jump 5-9)? I certainly prefer this interpretation, to be honest.

(I also like to think that there is a minimum "microjump" or "Jump-0" distance beyond which you cannot go based on some type of Uncertainty Principle or other, but that the distance is so small in-system (hundreds of thousands or millions of kilometers) that it is not normally talked about in practical circles save by academics and theorists, as it would usually be quicker to use M-Drives over such a distance anyway.)

I think I prefer the "No Microhops" rule

You are either
1. carrying an extra jump drive to adjust for errorrs
OR
2. Going between "Saturn stations" that have jump ferries down to the main world

The advantage is the massive amount of fuel saving

You can have a 9 parsec run

J0-H1-J0,,, each time it only uses 10% of the ship for fuel and the whole thing takes 3 weeks (speed of Jump 3)

for a 30 parsec run... you need 30 % of the hop ship for fuel (since you can't stop to refuel)
J0-H(3, 2+1, 1+1+1)-J0.... and depending on your hop tech is a speed of Jump 10, 7.5, or 6

 

[Badenov]

So I have to wonder about hop, skip, and jump drives. If a distance is just a hop, a skip, and a jump to get there, it shouldn't be very far ar all.

 

[Krikkitone]

So I have to wonder about hop, skip, and jump drives. If a distance is just a hop, a skip, and a jump to get there, it shouldn't be very far ar all.

111 parsecs (very important birthday considerations)

 

[whulorigan]

111 parsecs (very important birthday considerations)

An Eleventy-One Holiday getaway . . .

 

[whulorigan]

So I have to wonder about hop, skip, and jump drives. If a distance is just a hop, a skip, and a jump to get there, it shouldn't be very far ar all.

Sure, but the Higher-TL higher order drives are way faster and more efficient by Leaps & Bounds.

 

[spank]

Booooooooo!

Sure, but the Higher-TL higher order drives are way faster and more efficient by Leaps & Bounds.

 

[spank]

I think Micro-Hop is largely irrelevant, the big issue is the 1000D limit which limits you to Hops beyond the orbit of Saturn.

Higher order drives are most likely going to be carrying either,
1) A second low-order drive
2) A high potential G-drive,
3) A Shuttle / Dropcraft to transit to the main world.
The 1000D limit means you are coming out Billions of Kilometers away from the star. For a type K main sequence this means ~158 hours @ 1 G for a KV 0 star to ~66 Hours @ 1G for KV 9 star. Even at 9G you are looking at ~22 to 52 hours for the transit.

The problem get even works with Skip, Bound, Leap ETC. With a Skip Drive you are going to be coming out deep in the Oort cloud.
The big advantages are going to be fuel savings and speed.

A Hop-1 Drive ship can make 3-4 Hops spending 10% fuel each time, A J-5 or J-6 ship is going to have to refuel each time. Short of having dedicated jump tenders standing by, or drop tanks ready to bolt on the Jump ship is going to fall behind quickly.

I think I prefer the "No Microhops" rule

You are either
1. carrying an extra jump drive to adjust for errorrs
OR
2. Going between "Saturn stations" that have jump ferries down to the main world

The advantage is the massive amount of fuel saving

You can have a 9 parsec run

J0-H1-J0,,, each time it only uses 10% of the ship for fuel and the whole thing takes 3 weeks (speed of Jump 3)

for a 30 parsec run... you need 30 % of the hop ship for fuel (since you can't stop to refuel)
J0-H(3, 2+1, 1+1+1)-J0.... and depending on your hop tech is a speed of Jump 10, 7.5, or 6

 

[AnotherDilbert]

Higher order drives are most likely going to be carrying either,
1) A second low-order drive
2) A high potential G-drive,
3) A Shuttle / Dropcraft to transit to the main world.
The 1000D limit means you are coming out Billions of Kilometers away from the star. For a type K main sequence this means ~158 hours @ 1 G for a KV 0 star to ~66 Hours @ 1G for KV 9 star. Even at 9G you are looking at ~22 to 52 hours for the transit.

Agreed.

As M-drives works badly over 1000D a slight astrogation mistake will basically leave you stranded.
So a secondary drive is advisable, either jump or NAFAL. At high tech both drives are fairly small and cheap, but the jump drive would require more fuel.


If we can make Anti-matter power plants, the fuel problem goes away.


At high tech small extra drives can be very small and cheap, in the order of <1% of the ship, e.g. a 2000 Dt Hop-1 ship at TL-16:

TL-16  F-VU11                        Ergo 3   Comfort 4    Demand 0        Agility -1
       Freighter                     Total:           0         448        Stability 0
SYSTEM                                    #        DTON        COST     
                                                                        
Hull                                              2 000                 
Config: Unstreamlined                                            52     
Structure: Plate HullMetal     AV=8 ( 80 vs Blast, 2400 vs Heat/Beam, 80 vs Pres, 800 vs Rad, 0 vs EMP )     
Coating: Reflec                AV= 0 ( 1600 vs Heat/Beam  )     
Armour Std Anti-Rad                       1                          AV=8 ( 80 vs Blast, 800 vs H/B, 800 vs Rad, 0 vs EMP )     
Landing Skids Tarmac                                                     
Lifters Installed                                                10     
                                                                        
Jump Field: Jump Plate                                            2        Flash 8
Ear H Drive M  H-1, 1080 EP               1          70         280     
Ult J Drive H  J-1, 1040 EP               1          11          34     
Ult M Drive D2  1 G, 1040 EP              1           4          24     
Ult N Drive D2  1 G, 1040 EP              1           4          12     
Ult P Plant H  P 1, 1040 EP               1           6          19

Spoiler:

Fuel, Jump   J-2                                    440                 
Fuel, Power  4 weeks                                 14                 
Purifier                                  2           2           1     
Scoops                                    1           1           0     
Water Intake                              1           1           0     
                                                                        
Console, Control Gen C+S=15              12          24           2        Brain: INT=4, EDU=2
Console, Operati Gen C+S=15               7          14           1        Brain: INT=4, EDU=2
Computer Gen m/1                          1           1           1     
                                                                        
Sensors                                                                 
Mod AR Surf Commu-10 +12A+7 PA(           1                       2       
Gen AR Surf CommP-16 +16A+7 PA(           1                       2       
Mod AR Surf EMS-14 +16A+7 PA(El           1                       2        ACS S=7
Mod AR Surf Visor-16 +18A-- P(P           1                       2        ACS S=5
Mod AR Surf Neutr-12 +14A-- P(G           1                       2        ACS S=7
                                                                        
Crew:                                     4                             
Stateroom for 1                           4           8           0     
Freshers Shared                           2           1           1     
Common Areas                              7           7                 
Life Support:                                                           
Med Console                               1           1           1     
Life Support, Standard 200%               1           1           1        240 person-days
Escape Capsules 200%                      1           1           1         10 people
                                                                        
Standard Air Lock                        20                             
                                                                        
Cargo                                             1 369                 
Spare Space                                          20                 
                                                                        
                                                                        
                                       Crew    Consoles      Panels     
Crew                                 4               19          17     
Bridge Crew                          2    0                             
    Pilot                                 1           1           1     
    Astrogator                            1           1           0     
    Sensor Ops                            0           1           5     
Engineer                             2    0                             
    Engineer                              1           5           9     
    Maintenance                           1                             
Service Crew                         0    0                             
    Operations                            0           1           2     
Gunner                               0    0                             
    Gunner                                0          10           0

 

[spank]

NAFAL is an interesting option, presumable it works just like a M-Drive, but without the 1000D limit. But performance is P=G/10 so even potential 9 it will only be 0.9G accel. But, OTOH with HOP you should be shooting for ~1000D, So you would really only need a little nudge to get close enough for the Star to M-Drive to work.
Presumably once Hop is established there would be a network of Hop Stations where the ships drop cargo for transit to the star. And the Hop-ships would only ever visit stations, and Jump ships, NAFAL ships or high-G system boats would take the freight and passengers from there. More backwater stars might require specialized ship that would have NAFAL for transit to the main world. I could even see some of these ships getting by with just M-drive since you breakout at 1000D and M-drive is effective out to 1000D. Maybe add 1 day to the transit time for M-drive to function at 1% efficiency before getting in close enough grab the star.

 

[AnotherDilbert]

NAFAL is an interesting option, presumable it works just like a M-Drive, but without the 1000D limit. But performance is P=G/10 so even potential 9 it will only be 0.9G accel. But, OTOH with HOP you should be shooting for ~1000D, So you would really only need a little nudge to get close enough for the Star to M-Drive to work.

Safe jump distance is modified by jump field and drive efficiency, so an Experimental Hop drive will jump and break out at ~2800 D.
D = S / E = 10 × 140 / 0.5 = 2800 as we have low efficiency (50%) and need jump plates (S = 140). See B2, p73.

At 2800 D we really need NAFAL or a jump drive...

Presumably once Hop is established there would be a network of Hop Stations where the ships drop cargo for transit to the star. And the Hop-ships would only ever visit stations, and Jump ships, NAFAL ships or high-G system boats would take the freight and passengers from there.

Yes, same problem as with really large stars, but on steroids.

2800 D from a red giant we hardly talk about a microjump any more, it's almost a regular jump followed by a week or so of acceleration.

The problem is Hopping to the station with the massive jump shadow (hop shadow?) of the star potentially blocking the path. To solve that we need several stations, so we can get to it and the cargo can jump towards the main world without being blocked by the star's much smaller jump shadow.

Something like this:

Hop station 1 wouldn't help us much, but Hop Stations 2 and 3 would. We can come closer to the destination world with a jump from Hop station 2, so that is better placed at this time. That will change as the world and stations orbits the star at vastly different angular speeds.
(The Jump limit is not to scale, it should be much smaller.)

The Hop limit only shrinks down to 1000 D at TL-17 for Hop-1.

 

[whulorigan]

As M-drives work badly over 1000D a slight astrogation mistake will basically leave you stranded.
So a secondary drive is advisable, either jump or NAFAL. At high tech both drives are fairly small and cheap, but the jump drive would require more fuel.

NAFAL is an interesting option, presumable it works just like a M-Drive, but without the 1000D limit. But performance is P=G/10 so even potential 9 it will only be 0.9G accel. But, OTOH with HOP you should be shooting for ~1000D, So you would really only need a little nudge to get close enough for the Star to M-Drive to work.
Presumably once Hop is established there would be a network of Hop Stations where the ships drop cargo for transit to the star. And the Hop-ships would only ever visit stations, and Jump ships, NAFAL ships or high-G system boats would take the freight and passengers from there. More backwater stars might require specialized ship that would have NAFAL for transit to the main world. I could even see some of these ships getting by with just M-drive since you breakout at 1000D and M-drive is effective out to 1000D. Maybe add 1 day to the transit time for M-drive to function at 1% efficiency before getting in close enough grab the star.

Keep in mind there is always the T-Drive ("Thruster") as well, which is a maneuvering/impulse drive that has no acceleration/diameter limits; as long as it has power, it continues to produces thrust.

If you dislike the "Dean-drive" concept behind it (as I do), just reimagine some of the physics (I reimagine it as something similar to the MT/DGP Thruster Plate using Hypergravity/Strong/Weak Nuclear Force Unification interactions - Spin Angular Momentum in N-Space is bled into the Hyper/Jumpspace realm (where it is compensated by an opposing reaction) that through a complex interaction produces a translational particle-momentum reaction there that is compensated by a corresponding and opposing translational momentum against the Thruster Plate.)

If we can make Anti-matter power plants, the fuel problem goes away.

I think the higher order drives presume you are employing antimatter power, since it is available

 

[spank]

I imagine it as an outgrowth of Jump Drive, grasping space instead of mass.

Keep in mind there is always the T-Drive ("Thruster") as well, which is a maneuvering/impulse drive that has no acceleration/diameter limits; as long as it has power, it continues to produces thrust.

If you dislike the "Dean-drive" concept behind it (as I do), just reimagine some of the physics (I reimagine it as something similar to the MT/DGP Thruster Plate using Hypergravity/Strong/Weak Nuclear Force Unification interactions - Spin Angular Momentum in N-Space is bled into the Hyper/Jumpspace realm (where it is compensated by an opposing reaction) that through a complex interaction produces a translational particle-momentum reaction there that is compensated by a corresponding and opposing translational momentum against the Thruster Plate.)

 

[AnotherDilbert]

Keep in mind there is always the T-Drive ("Thruster") as well, which is a maneuvering/impulse drive that has no acceleration/diameter limits; as long as it has power, it continues to produces thrust.

Yes, unfortunately.

As it is unencumbered by gravity and physics in general, it should work in jump space, so we have again turned our ship into kinetic city-killers. The very problem limited range M-drives was supposed to solve?

I would banish it to the nether hells of FF&S, from whence it came.

 

[spank]

Yes, unfortunately.

As it is unencumbered by gravity and physics in general, it should work in jump space, so we have again turned our ship into kinetic city-killers. The very problem limited range M-drives was supposed to solve?

I would banish it to the nether hells of FF&S, from whence it came.

NAFAL can get you up to .9c, {in theory} so you still got the same problem.
Heck, An M-Drive will get you up a pretty good head of steam if you start at 1000D on a G2 V type Star and accelerate all the way thru the 1000D bubble.
But with the variability of the jump's duration your going to have a hard time hitting your target.
Imagine Lee Harvey in the book depository but he has to pull the trigger a week before hand, and only knows that the rifle will fire in a 24 hour window.

 

[spank]

Thinking about it,
If you optimize your vector to minimize relative motion you could stand a fairly good chance of hitting the planet.
You'd need to pick a point where you are edge on to the "disc" of the "orbit" either directly in the path of the orbit, or behind it.
Coming in at a tangent to the orbit, the planet will move thru an arc about .986 degrees of a circle.
If my math is right, the Earth should move laterally about 5,500 Km during this time. So with an optimal exit point timing becomes less critical.
But that's only to hit the planet, not to hit a particular spot on the planet. And it means there are VERY particular points where such an attack would come from. Instead of trying to detect such an attack from anywhere in a spherical area it will be in a very small cone directly ahead of and behind the planet.
Please forgive my very crude made-on-a-phinr drawing,

 

[whartung]

But with the variability of the jump's duration your going to have a hard time hitting your target.

Sure, but if planet killing is the goal, no reason to send just one. Send out 100-200, and let random chance hit the target. What's 200 ships in terms of cost against an entire planet.