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

[Fractal_UK]

Problem, even with 2 Nuclear Reactors and 4 Energy Generators, the Xenon-powered Plasma Thruster has only about 25 kN thrust.

The ship is modular, so I can exchange the machine section with something else... What should I do?

It's not supposed to be fast, but I wanted to put it into a munar orbit, which is... Well, currently out of the question.

Its thrust will go up a bit in the next update as I'll be rebalancing the reactor outputs, with 2.5m reactors you will see thrust rise by over just over 60%. You could add more reactors to add more thrust as well as using up some science to upgrade the reactors.

That said, a nuclear electric rocket isn't going to be speedy no matter what you do with it though. If you're having to use xenon, you're probably better off switching to a thermal rocket because you're seeing only 50% better specific impulse but losing a lot of thrust in the process. It's probably a good combination to use for tweaking your orbit but not for a journey to the Mun.

[forsaken1111]

Fractal: I haven't tested this. Will 2 nuclear reactors attached to a single generator provide 2x the power from the generator? Or does it only use the thermal power from one?

[Bibblejw]

Fractal: I haven't tested this. Will 2 nuclear reactors attached to a single generator provide 2x the power from the generator? Or does it only use the thermal power from one?

Theoretically, unless the code only checks for one, it should have the capacity to use both, it's the same generator that the AM reactors use, after all.

[forsaken1111]

Theoretically, unless the code only checks for one, it should have the capacity to use both, it's the same generator that the AM reactors use, after all.

Thats why I am asking the mod developer. I suspect that the generator detects the attached reactor and adjusts its output based on that but I am wondering if he gave any thought to multiple attached reactors.

As an example, using the editor extensions mod I could radially attach 4 smaller nuclear reactors to a single large generator. Would it handle that correctly? Would it handle two reactors attached above and below the generator in a stack?

I'm just giving him use cases that he may not have thought of, and wondering if those cases are handled.

[Donziboy2]

Another minor question. Anyone give the approximate lifting power of a simple rocket (small AM, thermal engine, etc.) into standard 100k orbit? What sort of payloads/what are people's preferred configs?

Take a look at the thrust values given below and do this. TWR = Thrust / (mass x gravity) ....... gravity is 9.81 for Kerbin, and thrust for the small AM reactor with Liquid fuel only is 1111kN. So if you shoot for a 1.01 TWR you can lift 113T into orbit.

For LFO multiply thrust by 2 and for Kethane multiply by 1.33.

[Fractal_UK]

Thats why I am asking the mod developer. I suspect that the generator detects the attached reactor and adjusts its output based on that but I am wondering if he gave any thought to multiple attached reactors.

As an example, using the editor extensions mod I could radially attach 4 smaller nuclear reactors to a single large generator. Would it handle that correctly? Would it handle two reactors attached above and below the generator in a stack?

I'm just giving him use cases that he may not have thought of, and wondering if those cases are handled.

You can't, you have to use one generator per reactor. I have thought about including this but it gets rather awkward if you mix and match, say you have two reactors of different power outputs and different core temperatures attached to one generator. It's not especially difficult to code but the results would probably be confusing when you have something attached to one upgraded reactor and one basic one and I think it's an extra complication that we don't really need.

Keep it simple and have one generator for each reactor.

[Bibblejw]

Take a look at the thrust values given below and do this. TWR = Thrust / (mass x gravity) ....... gravity is 9.81 for Kerbin, and thrust for the small AM reactor with Liquid fuel only is 1111kN. So if you shoot for a 1.01 TWR you can lift 113T into orbit.

For LFO multiply thrust by 2 and for Kethane multiply by 1.33.

Ok, thanks for the response. I get TWRs, how to work them out, etc. My main thing is concerned with the amount of fuel. For instance, a 1.01 TWR will have you accelerating somewhat slowly (going through the calculations, a 11,111kN thrust at 1.01 TWR gives 111.11kN usable force. Applying f=ma gives an accelleration that's got far too many 0's before it for my liking), and basically hovering over the launch pad until you've burnt enough fuel to get a useable TWR.

I was really just asking for a general rule of thumb that people used (such as mine is that my standard launch vehicle can take 30t to a 100k with no issues, above that, and fuel issues come into play).

[NeoAcario]

Might have a look at KAS. Not been too long in the KSP modding stuff, so unsure of what's around, but something to prevent my stations wobbling out of existence, and transferring resources without needing both ships to be fully docked would be nice.

Having wobble problems? Get Quantum Strut. GET IT! It's especially useful for space stations. I place a couple around each docking port and they basically establish tractor beam style struts whenever anything docks.

Another minor question. Anyone give the approximate lifting power of a simple rocket (small AM, thermal engine, etc.) into standard 100k orbit? What sort of payloads/what are people's preferred configs?

Upgraded small AM with thermal nozzle can lift 100 tons into LKO with about 30,000 Kethane.

~Steve

PS. Fractal_UK is trying to make me beg/cry... big meanie.

Edited October 11, 2013 by NeoAcario

[forsaken1111]

You can't, you have to use one generator per reactor. I have thought about including this but it gets rather awkward if you mix and match, say you have two reactors of different power outputs and different core temperatures attached to one generator. It's not especially difficult to code but the results would probably be confusing when you have something attached to one upgraded reactor and one basic one and I think it's an extra complication that we don't really need.

Keep it simple and have one generator for each reactor.

That's fine, I was just curious if I could shave off some weight by doing multiple reactor/single generator setups.

Another question though, would your generator detect a radially-attached reactor? I know they cannot normally attach radially but the editor extensions mod allows radial attachment for parts that do not normally. If I stuck a reactor on a generator radially, would it detect it as normal?

I'll test when I get home if you haven't answered or are unsure.

[cy-one]

I'm a little bit confused about the Antimatter Flux-readout from the Magnetometer. It shows 4.61 on Kerbin at 900km Altitude... An orbit which is described as more or less ideal. If so, why does it read 5.88 at 200km?

[Fractal_UK]

Another question though, would your generator detect a radially-attached reactor? I know they cannot normally attach radially but the editor extensions mod allows radial attachment for parts that do not normally. If I stuck a reactor on a generator radially, would it detect it as normal?

Yes, the code isn't limited to detecting via attachment nodes so provided you stick them directly onto each other with nothing in between it should work fine.

I'm a little bit confused about the Antimatter Flux-readout from the Magnetometer. It shows 4.61 on Kerbin at 900km Altitude... An orbit which is described as more or less ideal. If so, why does it read 5.88 at 200km?

Different order of magnitude, most likely. What are the numbers after the "e" ?

[forsaken1111]

I'm a little bit confused about the Antimatter Flux-readout from the Magnetometer. It shows 4.61 on Kerbin at 900km Altitude... An orbit which is described as more or less ideal. If so, why does it read 5.88 at 200km?

Look at the whole number. That is probably 5.88x10-9 or something, which is TINY, while the other may be 4.61x10-7 which is... still tiny but much larger than the first number.

http://en.wikipedia.org/wiki/Scientific_notation

[NeoAcario]

beat me to it, forsaken1111...

Although it is curious to see someone interested in KSP that isn't a math/science buff.

~Steve

EDIT: Basically, cy-one, that E means to move the decimal in the number. If it's negative you move it left and if it's positive you move it right. Do this for the number next to the E.

So that 4.612303E-5 is actually 0.00004612303 units per second per collector.

Edited October 11, 2013 by NeoAcario

[forsaken1111]

beat me to it, forsaken1111...

Although it is curious to see someone interested in KSP that isn't a math/science buff.

~Steve

You don't need to be a math buff you understand the notation. I learned this in grade school...

[cy-one]

beat me to it, forsaken1111...

Although it is curious to see someone interested in KSP that isn't a math/science buff.

~Steve

That's why a lot of my stuff is Trial & Error as well as MJ-based

[NeoAcario]

You don't need to be a math buff you understand the notation. I learned this in grade school...

In this day and age, in the USA (I'm ashared to admit), you have to be a 'buff' in something to pay attention to it in school.

~Steve

[forsaken1111]

As a rule of thumb, you want the highest number at the end there, so for example if it says -7 at one orbit and -9 at another you want the -7, that is a higher flux and yields more antimatter.

Though with so many people asking about it, maybe Fractal should just put in a chart or graphical indication.

[NeoAcario]

Though with so many people asking about it, maybe Fractal should just put in a chart or graphical indication.

He's probably making the same assumption that I am: Anyone that likes a game built around physics will know the basics of physics.

~Steve

P.S;

I'm starting to wonder if Thermal Nozzles are a bit OP... I'm down to ~3% fuel and still have 7k dV left. HAH!

Edited October 11, 2013 by NeoAcario

[forsaken1111]

He's probably making the same assumption that I am: Anyone that likes a game built around physics will know the basics of physics.

~Steve

P.S;

I'm starting to wonder if Thermal Nozzles are a bit OP... I'm down to ~3% fuel and still have 7k dV left. HAH!

Hehe...

new people to this mod: OMG SO COMPLICATED AND NOTHING WORKS, ITS ALL SO WEAK

People who understand the mod: Holy crap this may be overpowered... can we make it more complex?

[Donziboy2]

Ok, thanks for the response. I get TWRs, how to work them out, etc. My main thing is concerned with the amount of fuel. For instance, a 1.01 TWR will have you accelerating somewhat slowly (going through the calculations, a 11,111kN thrust at 1.01 TWR gives 111.11kN usable force. Applying f=ma gives an accelleration that's got far too many 0's before it for my liking), and basically hovering over the launch pad until you've burnt enough fuel to get a useable TWR.

I was really just asking for a general rule of thumb that people used (such as mine is that my standard launch vehicle can take 30t to a 100k with no issues, above that, and fuel issues come into play).

When it comes to the thermal rocket engine, you don't really need a launch stage, they can lift themselves, unless your using nuclear reactors. I have a 2.5m AM ship that can land on most planets that weighs over 300T on the launch pad. I have to limit its thrust since it uses LFO, it has a TWR of like 2.

And forsaken1111 you are so spot on with that lol:)

[NeoAcario]

Hehe...

new people to this mod: OMG SO COMPLICATED AND NOTHING WORKS, ITS ALL SO WEAK

People who understand the mod: Holy crap this may be overpowered... can we make it more complex?

Well I'm still testing this mod.. so this is my test ship. I decided: "Hell, I'm almost out of fuel... why not do a standard planetary transfer back to Kerbin and pretend this thing doesn't have a warp drive. Crap, only have 9.5k dV left.. hope it's enough to get back."

Now I'm sitting in Kerbin orbit laughing at myself. Still over 7k dV left and then it hits me... "Oh yeah, 9.5k dV was an insane amount for any standard propulsion. Doesn't matter if it's only 3-4% of the 96,000 Kethane tank worth."

~Steve

[forsaken1111]

I've been really enjoying my kethane tug that uses an aluminum/oxygen rocket to lift kethane from the mun surface to my depot. It refuels itself on the surface for 'free' and doesn't burn up kethane to do so.

[NeoAcario]

Upon extensive testing... I've come to the conclusion that (at current settings) Plasma Thrusters are only good in 3 situations:

1> Long duration Atmospheric Flight (liquid fuel)

2> Short term heavy lifts (only applies with Xenon using the upgraded 2.5m or 3.75m)

3> Infinite low thrust space flight (upgraded thruster)

For all others I honestly feel that the Thermal Nozzles with Kethane are the best bet... as it pertains to thrust/isp and ease of refueling Kethane.

Anyone care for debate?

~Steve

Edited October 11, 2013 by NeoAcario

[Donziboy2]

Upon extensive testing... I've come to the conclusion that (at current settings) Plasma Thrusters are only good in 3 situations:

1> Long duration Atmospheric Flight.

2> Short term heavy lifts (only applies with Xenon using the upgraded 2.5m or 3.75m)

3> Infinite low thrust space flight (upgraded thruster)

For all others I honestly feel that the Thermal Nozzles with Kethane are the best bet... as it pertains to thrust/isp and ease of refueling Kethane.

Anyone care for debate?

~Steve

I think Fractal_UK is working on them I believe, also once he fixes the large microwave receiver you can use solar tugs. Or at least once he releases the update with the fix.

[forsaken1111]

So a vessel with an upgraded plasma thruster and a microwave receiver could more or less go forever so long as it was getting power, right?