[0.25]KSP Interstellar (Magnetic Nozzles, ISRU Revamp) Version 0.13

[pina_coladas]

You need fuel lines to transfer oxidiser and liquid fuel as you would between stacks on a rocket. The fuel line needs to go from the tank to the refinery (the opposite way to what you might expect).

This is pretty much the worst right here. I'm not sure what you could do without disrupting the normal fuel flow logic of the game but the reverse fuel lines thing is the bane of every ISRU mod and gets everybody at one point or another. Would it be possible to make everything the refinery outputs flow like monopropellant without changing the way fuel flows to engines?

[rosenkranz]

Different question on plasma engines. Quantum Vac mode. What is that and how do i use it. I can't seem to find a part that produces it or stores it.

[Lightwarrior]

Different question on plasma engines. Quantum Vac mode. What is that and how do i use it. I can't seem to find a part that produces it or stores it.

It is just infinite in space.

[db48x]

Different question on plasma engines. Quantum Vac mode. What is that and how do i use it. I can't seem to find a part that produces it or stores it.

That upgrade allows you to push against the quantum structure of space and time itself, meaning that you need no fuel. You do need to be in vacuum though. Of all the things in this mod, I'd have to say that this is the most hypothetical, even moreso than the warp drive. Enjoy!

[Teh_SAUCE]

This is amazing. The most fun I've had playing KSP in a long time.

Thank you

PDubs

[EdisonMaxwell]

In some of your pictures I saw you're using only the antimatter reactor and a container(which isn't supposed to contain any antimatter in the beginning) on the ground. Is that possible or just something for the picture?

[kalizec]

Yes, they are mostly unusable with small unupgraded reactors.

But if you take 3.75m thorium reactor you may get something usable... but yes it is not a "small probe" at all.

Just use thermal nozzles, they are better at this "tech level". And it seems right.

BTW just tested it with 1.25m fusion Helium-3 reactor and xenon... interesting... ~45KN of thrust and TWR>1 on kerbin.

I've got the feeling we're talking 'past' each other. I'm trying to explain that as they currently are, unupgraded Plasma Thrusters are useless from a game perspective.

I appreciate the 'help' by telling me that I need more power and that will make them useful. I understand that. But that doesn't make them useful before they're upgraded.

So that doesn't solve the issue I'm having with them.

From a technical standpoint the Plasma Thrusters are currently perfectly balanced. But it's from a game standpoint that they're useless.

Why? Because the amount of game time it takes to use them makes them irrelevant (I'm not willing to let this game run hours on end at 4x time acceleration just so I can use these parts).

So if you agree they are useless until upgraded, why not make them useful? Squad has done the exact same thing with their Ion parts. Which are also at the same tech-level.

They've given those unrealistic thrust levels, not because they think that's how it works in real-life. But because they recognize having a 20 minute burntime is a lot more

acceptable than having a 2000 minute burn-time.

[rosenkranz]

That upgrade allows you to push against the quantum structure of space and time itself, meaning that you need no fuel. You do need to be in vacuum though. Of all the things in this mod, I'd have to say that this is the most hypothetical, even moreso than the warp drive. Enjoy!

Pretty cool. Seems kinda overpowered until you realize how much AM you're going to consume using it. Haven't tried it yet on an upgraded fission reactor.

Did notice some kind of weird behavior though. I had a ship with one 2.5m am-reactor and one 2.5m generator with 4 1.25 plasma's on pylons. If I let mechjeb do the take-off it's habit of flooring the throttle apparently plays merry hobb with the plasma's as two or three of the four will cut out for lack of power. However if I throttle up manually or enable MJ's 'smooth throttle' option, it works fine.

I tried again with four of everything on the pylons and every once in a while (like the first time) it worked. Otherwise it did the same thing.

Unfortunately this leads to asymmetric thrust and rapid dis-assembly if it happens on the pad.

@db48x, some folks are modding the tanks to have some AM handy at launch (1% is what i've got mine set to). This does make some sense to me as you'd think with ground facilities would be able to supply at least enough to get to orbit. Though what would make more sense, is that there be an upgrade to the tanks so that when you first get them, they would start empty but after the upgrade, they would start with 1-5% in them. (maybe that's one for the suggestion box)

[Lightwarrior]

kalizec ,

There was discussion few pages above about this first reactors and power generation/thermal nozzles. Even with thermal nozzle there they are just marginally better than stock LV-N, if designed properly.

An IMO it is OK, you just need to think twice before even trying to use them.

And yes, this is only my point of view....

[Donziboy2]

Different question on plasma engines. Quantum Vac mode. What is that and how do i use it. I can't seem to find a part that produces it or stores it.

It is the final upgraded mode for the plasma thruster, it has the same kN/MW ratio as LF but uses no fuel, it only works in vacuum.

[Donziboy2]

I've found the problem, I'm really embarrassed, the atmospheric code in version 0.9 would've worked perfectly if it wasn't for a typo. I've since reverted to earlier code and been messing about with lots of wacky solutions when the original solution should have worked (and now does work) brilliantly.

It's christmas eve tomorrow so no promises but I'll try and put a new version with this fix included out tomorrow.

Thats great to hear.

Yes you should be building Kristmas Trees and hanging with family;)

[imasquare]

Fractal, do you mind if I release bigger part.cfg files to provide 2.5m and 3.75m parts for people who don't know how to edit these files?

[Northstar1989]

Larger turbojets, however, will probably get added soon.

At the moment all radiators are assumed to have emissivity = 1. My impression is that, in space radiator systems, the practical emissivity is almost always very close to 1 and that choice of material actually makes only the most marginal difference. The value would start comfortably over 0.9 for the unupgraded radiators (most likely even higher than 0.95) so I don't really see the point of modelling it.

OK, first of all, with emissivity- what are the chances of seeing a radiator with an emissivity GREATER THAN 1 then. In real life, several types of nano/metamaterials actually exceed the blackbody limit by having emissivity significantly greater than 1... So it would seem logical (and more accurate) to make a third-tier radiator with higher emissivity available at Experimental Electrics or Metamaterials, and push back the Graphene radiators to an earlier tech node...

Second, any idea when we can expect larger thermal turbojets by? And any chance we could get larger intakes (if it really must be stock, then fine- but surely you could add a 2.5, 3.75, or even 5-meter Ram Intake to go with the larger turbojets? It would help to have intakes available at a 50% or more LARGER diameter than the turbojets, to reduce the number of intakes needed for high-altitude...)

Third, what about getting smaller Aluminum Hybrid Rocket Engines like I asked about before? I can't see any reason the engine needs to be as large (and heavy) as a small house at Kerbal-scale...

Regards,

Northstar

Edited December 24, 2013 by Northstar1989

[kalizec]

kalizec ,

There was discussion few pages above about this first reactors and power generation/thermal nozzles. Even with thermal nozzle there they are just marginally better than stock LV-N, if designed properly.

An IMO it is OK, you just need to think twice before even trying to use them.

And yes, this is only my point of view....

Can you then explain why you think it's ok? For example, can you provide a suggestion for a useful craft you could build using these unupgraded parts that can perform, for example, an injection burn from LKO to Duna in reasonable game-time?

Some examples that show the huge disparity between the ingame ion-engine and the plasma thruster:

• OKTO2
  
• PB-X150 Xenon
  
• 62.5cm Electric Generator
  
• 62.5cm "SAFE-1500"
  
• Small Heat Radiator (x2)
  
• PB-ION Electric Propulsion System
  

Mass: 1471kg

Delta-V: ~2300 m/s

MaxA: ~350 mm/s^2

Total burntime: ~90 minutes.

• OKTO2
  
• PB-X150 Xenon
  
• 62.5cm Electric Generator
  
• 62.5cm "SAFE-1500"
  
• Small Heat Radiator (x2)
  
• 1,25m plasma thruster
  

Mass: 2223kg

Delta-V: ~480 m/s

MaxA: ~14 mm/s^2 (not a typo, really, millimeters per seconds squared).

Total burntime: ~525 minutes.

P.S. a 62,5cm plasma thruster could weigh less (doesn't seem to exist), given the 2,5 to 1,25 scaling a 62,5cm one would weigh about 150kg.

Mass: 1371kg

Delta-V: ~710 m/s

MaxA: ~23 mm/s^2

Total burntime: ~525 minutes.

So the ion-engine wins on specific impulse, twr, max-acceleration and delta-v.

Suggestion: Up the Plasma Thrusters thrust until it is comparable to the ion-engine (of course taking into account different thrust values for different Isp values of each propellant type).

Edited December 24, 2013 by kalizec
Spelling, etc

[Ralathon]

Can you then explain why you think it's ok? For example, can you provide a suggestion for a useful craft you could build using these unupgraded parts that can perform, for example, an injection burn from LKO to Duna in reasonable game-time?

Some examples that show the huge disparity between the ingame ion-engine and the plasma thruster:

• OKTO2
  
• PB-X150 Xenon
  
• 62.5cm Electric Generator
  
• 62.5cm "SAFE-1500"
  
• Small Heat Radiator (x2)
  
• PB-ION Electric Propulsion System
  

Mass: 1471kg

Delta-V: ~2300 m/s

MaxA: ~350 mm/s^2

Total burntime: ~90 minutes.

• OKTO2
  
• PB-X150 Xenon
  
• 62.5cm Electric Generator
  
• 62.5cm "SAFE-1500"
  
• Small Heat Radiator (x2)
  
• 1,25m plasma thruster
  

Mass: 2223kg

Delta-V: ~480 m/s

MaxA: ~14 mm/s^2 (not a typo, really, millimeters per seconds squared).

Total burntime: ~525 minutes.

P.S. a 62,5cm plasma thruster could weigh less (doesn't seem to exist), given the 2,5 to 1,25 scaling a 62,5cm one would weigh about 150kg.

Mass: 1371kg

Delta-V: ~710 m/s

MaxA: ~23 mm/s^2

Total burntime: ~525 minutes.

So the ion-engine wins on specific impulse, twr, max-acceleration and delta-v.

Suggestion: Up the Plasma Thrusters thrust until it is comparable to the ion-engine (of course taking into account different thrust values for different Isp values of each propellant type).

Do note that Plasma Thrusters completely blows Ion engines out of the water once you reach higher energy levels. So yea, for low tech probes it's better to go with a ion engine, but once you have access to vast amounts of power the plasma engine wins. And that's okay with me, it doesn't trivialize the ion engine while still providing a niche where the plasma thruster is viable.

[kalizec]

Do note that Plasma Thrusters completely blows Ion engines out of the water once you reach higher energy levels. So yea, for low tech probes it's better to go with a ion engine, but once you have access to vast amounts of power the plasma engine wins. And that's okay with me, it doesn't trivialize the ion engine while still providing a niche where the plasma thruster is viable.

Except all that extra power is only available at higher tech levels with upgraded parts.

I'm not advocating that the plasma thruster be buffed at those higher tech levels.

I'm advocating that it shouldn't exist at -this- tech level OR be buffed at -this- tech level.

Preferably the latter of the two.

P.S. please stop telling me that it's better upgraded or at a higher tech level.... that's besides the point.

Edited December 24, 2013 by kalizec

[Gibster]

It was radial, the large deployable ones (refering to the bug i found)

Edited December 24, 2013 by Gibster

[Fractal_UK]

Suggestion: Up the Plasma Thrusters thrust until it is comparable to the ion-engine (of course taking into account different thrust values for different Isp values of each propellant type).

Let me show you what happens if I do this:

Stock ion engine 0.5kN thrust with specific impulse 4200s, total power = 0.5*500*9.81*4200 = 10.3MW. But it only uses 14.5KW worth of electrical power, so in order to make them comparable, I must multiply plasma engine thrust by 710.

Now a basic 1.25m nuclear reactor and 1.25m generator produces 71kN at 11,200s of specific impulse.

An upgraded 3.75m nuclear reactor and 3.75m generator produces 24,637kN at 11,200s.

An upgraded 3.75m antimatter and 3.75m generator produces 10,159,177kN at 11,200s.

This is totally stupid, the low powered reactor/generators used with plasma engines would obselete every other engine in the game and the high powered reactor/generators would be totally impossible to fly as they'd just break the ship in half the moment you throttled up above about 5%.

Honestly, this has come up before and I really don't see what the problem is. Plasma engines don't really work in KSP with small reactors and generators but it just doesn't matter - there are plenty of other engines you can use. Not every combination of parts has to make a good rocket, small unupgraded reactors and generatores are useful for lots of things, plasma thrusters are useful for lots of things too but they aren't the best when use together - so just use a different engine, like a thermal rocket or jet.

Besides, maybe KSP will have better physical timewarp options in future.

[rosenkranz]

I think what is really happening here is the expectation that a part be useful when it becomes available. The point at which plasma thrusters (and thermal rocket nozzles for that matter) become available, they are complete rubbish. They really don't become viable for propulsion until both reactors and generators have been upgraded.

So what really needs to happen isn't a tweak of the parts in question but to the tech tree and when parts become available. Move parts to more appropriate nodes so that they become available when they become useful.

[Lightwarrior]

kalizec,

Because it is more realistic, while not making game unplayable. You still have other ways to do what you want.

You just need to understand what you are doing, and do not try to use such things like plasma thruster with basic reactor.

And it represents our current real life situation very well IMO. We have reactors, have electric engines, but we do not use this things together in space.

BTW there are a lot of examples when it is better to use stock components than this reactors. One of them is thermal turbojet. Yes, it has infinite fuel. But it is just so slow... it is way easier to use stock turbojet. Another - thermal nozzles with smaller reactors (1.25/0.625). Just to low thrust and to small efficiency increase to compensate.

Also one thing i agree with - it would be nice to see more 0.625m parts. Some engines at least. Because now those 0.625 reactors seems "not so usefull" (in terms of propulsion, not utility).

I think what is really happening here is the expectation that a part be useful when it becomes available. The point at which plasma thrusters (and thermal rocket nozzles for that matter) become available, they are complete rubbish. They really don't become viable for propulsion until both reactors and generators have been upgraded.

...

You do not need upgraded generators at all. Only reactors.

With thermal nozzle you do not even need generator and even with basic generators you can power things like DT Vista using upgraded reactors. Yes, it is a bit harder than with upgrade, but not rubish at all.

And also 2.5/3.75m basic reactors can give good enough results with thermal nozzles.

Edited December 24, 2013 by Lightwarrior

[Fractal_UK]

I think what is really happening here is the expectation that a part be useful when it becomes available. The point at which plasma thrusters (and thermal rocket nozzles for that matter) become available, they are complete rubbish. They really don't become viable for propulsion until both reactors and generators have been upgraded.

So what really needs to happen isn't a tweak of the parts in question but to the tech tree and when parts become available. Move parts to more appropriate nodes so that they become available when they become useful.

They aren't completely rubbish, thermal rockets especially the larger ones are simply better than the stock nuclear engines and even the small ones offer more delta-v albeit without much thrust to write home about.

The plasma engine is harder to use without any upgrades but there is no guarantee about the order in which people will unlock the tech tree. I'm not going to legislate for player patience, I've seen people use rockets with far lower TWRs than I'd care for in order to maximise delta-v so the option is there if the player wants it.

It's worth noting as well that there is literally no way to use anything other than linear scaling (in other words, I can't make the nuclear powered ones better without making the more advanced tech ones better by the same factor) due to the way the plasma thrust works (adding up power from all sources of electricity) so it's totally impossible, due to the scales involved, to make the bottom end any more useful without causing the top end to shake your ship to pieces through excessive thrust.

This is definitely not something I'm going to change.

[kalizec]

Let me show you what happens if I do this:

Stock ion engine 0.5kN thrust with specific impulse 4200s, total power = 0.5*500*9.81*4200 = 10.3MW. But it only uses 14.5KW worth of electrical power, so in order to make them comparable, I must multiply plasma engine thrust by 710.

Now a basic 1.25m nuclear reactor and 1.25m generator produces 71kN at 11,200s of specific impulse.

An upgraded 3.75m nuclear reactor and 3.75m generator produces 24,637kN at 11,200s.

An upgraded 3.75m antimatter and 3.75m generator produces 10,159,177kN at 11,200s.

Only if you scale the thrust of the Plasma Thruster with power...

Instead you could scale the thrust with something else. Or limit the maximum thrust of the thruster somehow.

This is totally stupid, the low powered reactor/generators used with plasma engines would obselete every other engine in the game and the high powered reactor/generators would be totally impossible to fly as they'd just break the ship in half the moment you throttled up above about 5%.

I agree that if you simply increase the thrust to power ratio the results are stupid.

But do you agree that at basic tech the part is utterly useless?

Maybe the thrust should scale with something other than power? Like size/mass i.e. which is true in the real world?

Besides, maybe KSP will have better physical timewarp options in future.

It's highly unlikely we will ever have physical timewarp speeds above 10x.

P.S.

How about having the plasma thruster scale both its Isp and its thrust with some square root of power?

That way we could use the thrust-limiter to change the Isp on the fly. We could also increase the base

thrust of the plasma thruster. And it would still prevent the insane thrusts at upgraded tech?

Edited December 24, 2013 by kalizec

[Northstar1989]

I thought THIS bug was fixed by 0.90 (version I'm running)

Javascript is disabled. View full album

Note that the IntakeAtm was a LOT higher (around 50%) when this started happening- it just plummeted by the time I took screenshots due to the spin causing the intakes to point away from prograde...

Regards,

Northstar

[Donziboy2]

@kalizec Try using a 62.5cm reactor/gen with a few Ion thrusters... or download Near Future Propulsion which has engines that are a good middle ground before you upgrade all your reactors/gens. Your beating a very dead horse.

@Northstar1989 This has already been pointed out and Fractal_UK has fixed it for the next version.

[rosenkranz]

They aren't completely rubbish, thermal rockets especially the larger ones are simply better than the stock nuclear engines and even the small ones offer more delta-v albeit without much thrust to write home about.

The plasma engine is harder to use without any upgrades but there is no guarantee about the order in which people will unlock the tech tree. I'm not going to legislate for player patience, I've seen people use rockets with far lower TWRs than I'd care for in order to maximise delta-v so the option is there if the player wants it.

It's worth noting as well that there is literally no way to use anything other than linear scaling (in other words, I can't make the nuclear powered ones better without making the more advanced tech ones better by the same factor) due to the way the plasma thrust works (adding up power from all sources of electricity) so it's totally impossible, due to the scales involved, to make the bottom end any more useful without causing the top end to shake your ship to pieces through excessive thrust.

This is definitely not something I'm going to change.

You are right. I'm still wrapping my head around the numbers. I was going over the tables to see if i could site some examples and I can see where the 2.5m and 3.75m basic fission reactors do better than stock. And you are right, to each their own. Some have more patience than others.

The tables in the wiki on thermal nozzles only lists numbers for LiquidFuel the multipliers for other fuels as a foot note (so is easily overlooked). Run LFO through the little buggers and they do much better. In fact there really ought to be a .625 nozzle. Is there a googledoc of that table somewhere. I'd really like to flesh that out with all the possible fuel combo's to build up a better picture of there utility.

As to plasma, that table could use some love as well.

Did you see my note about the bad behaviour when the throttle is applied too quickly (i.e. under mechjeb's control).