[20/11/2014][0.25] FTmN Atomic Rockets

[KyleKidd]

I just did a Spotlight on the FTmN Atomic Rockets Mod. Check it out on YouTube: http://youtu.be/LfKemCP6YGA

[Streetwind]

Anyway, I'll finish up my little hexagonal engine tomorrow and put out an update.

Seen the Community Tech Tree yet?

It's designed so that a modder can ship a MM config with their mod that only activates if the Community Tech Tree is installed, and that MM config would then redistribute the modder's parts into the CTT's extended nodes as required. If you're already working on an update, this might be a good opportunity to hop onto this yet-young bandwagon.

[Temeter]

Hmm, I'll do some balancing next update. I did a bit of testing just building things in the VAB but I don't play the game that often these days so I'm not that clued up on how career mode is.

Edit: I've done a bit of haphazard balancing and realised I mis-specced the FTmN 180. Oops. Anyway, I'll finish up my little hexagonal engine tomorrow and put out an update.

Yeah, i noticed the 180 was a bit out of line. Personally I think balancing the prices around the relatively expensive stock nerva might be a good idea, matching the lv-n to the ftmn180.

Or maybe going a bit lower, the lv-n is actually priced around the idea of being op.^^

[Mystique]

Anyone tried removing old version and installing this one while have some crafts with old ftmn engines in flight? Is it safe to do so or those crafts using old engines will be broken?

[dtoxic]

Anyone tried removing old version and installing this one while have some crafts with old ftmn engines in flight? Is it safe to do so or those crafts using old engines will be broken?

i don't think you can do that, Folder changed and name 's changed better land your craft first

[Mystique]

i don't think you can do that, Folder changed and name 's changed better land your craft first

Yeah, got the same idea. They're expensive enough to avoid such experiments

BTW, is it possible to post new Isp values? As I understood from OP, they're now less efficient while more powerful, so it's worth to know exact numbers in order to know if these engines will be still usable.

Update: oh man, now stock NERVA is actually more preferable for efficiency =\ New looks of engines are cool, but is there really no chance that old Isp/TWR ratios can be kept (maybe as an optional config)?

Edited November 18, 2014 by Mystique

[DGatsby]

Huzzah! Great update!

[Kommitz]

I just did a Spotlight on the FTmN Atomic Rockets Mod.

Neat.

Seen the Community Tech Tree yet?

Yep!

I've released a small update. Mostly balancing, with reduced prices and increased Isp across the board (550 -> 570), but I also added a new, small engine and included a .cfg for Community Tech Tree.

Switchable mesh (hexagonal rocket nozzle, different base-plate designs/sizes) should be what I add next. No promises as to when I'll have them done.

Edited November 20, 2014 by Kommitz

[Eagleshift]

Regarding the new CKAN project (a package manager for KSP), I took the liberty of creating some metadata file for this mod, as it isn't listed (yet). Don't worry, it just lists the name of the mod, your name, where to download it and bits like the license and a short description. Most of it is pulled (automatically) from Kerbal Stuff.

Before requesting that my metadata be pulled to the main repository, I'd like to ask you if you approve that. I won't take any credit from it and only do it so that people who use the new package manager can view your mod easily

You can review the file :

{
    "spec_version"   : 1,
    "name"           : "FTmN Atomic Rockets",
    "identifier"     : "ftmn_new",
    "$kref"          : "#/ckan/kerbalstuff/339",
    "author"         : "Kommitz",
    "abstract"       : "Nuclear Thermal Engines balanced differently to the LV-N, offering improvements in TWR but a reduction in Isp.",
    "license"        : "restricted",
    "release_status" : "stable",
    "ksp_version_min": "0.25",
    "resources" : {
        "homepage"      : "http://forum.kerbalspaceprogram.com/threads/26286",
        "kerbalstuff"   : "https://kerbalstuff.com/mod/339"
    },
    "depends" : [
    ],
    "suggests" : [
        { "name" : "CommunityTechTree" }
    ],
    "install" : [
        {
            "file"       : "GameData/ftmn_new",
            "install_to" : "GameData"
        }
    ],
    "x_maintained_by": "eagleshift"
}

It's ready to go, just waiting for your validation !

Edited November 20, 2014 by Eagleshift

[NecroBones]

Your engines are way too pretty!

/envy

Good job!

[Kommitz]

It's ready to go, just waiting for your validation !

Oh, I hadn't heard about this but that looks fine. Feel free to add it.

[Temeter]

Thanks for the update! Looks great.

Nvm me being late to the party.^^'

Edited December 9, 2014 by Temeter

[Kommitz]

So update 0.90 is out, and everything is working fine. So I'll go right ahead and release a big old update soon!

With all this handy part sorting capability I'll get around to adding some of the alternate configurations for things, as a lot of the issues with 'part bloat' have been mitigated by the sorting and categories in the construction menu now. Basically means I won't end up adding in Firespitter as a dependency just for the mesh switching, although there's another plugin that I will add for mesh switching and enabling other useful features!

The end result will be that I add some proper fuel configs for the engines, and keep the 'stockalike' LiquidFuel & Oxidizer config as a legacy config for anyone that actually likes it.

Anyway: Next update is part categories and LiquidHydrogen configs, with accompanying tanks. Oh and also an enormous gascore engine that looks something like the old FTmN 280, so people that have ever wanted a 3.75m engine have something at least. It was just waiting for liquidhydrogen on account of the crazy balance issues (see: http://www.projectrho.com/public_html/rocket/enginelist.php#id--Nuclear_Thermal--Gas_Core--Open_Cycle).

Edited December 18, 2014 by Kommitz

[DGatsby]

Sounds good! I'm looking forward to it.

[harlikwin]

Quick question and comment, and I apologize in advance if it is a stupid one (and no I haven't actually played this mod in a recent form (played the way old one). But I like nuclear rockets.

I'm curious as to why you reduced the ISP of the engines to boost the thrust (I get the physics). The main advantage IRL of nuclear rocket design is the high ISP, is it just the burn time issue? Also any plans to have liquid core and gas core nukes? (even more ISP)?

[Tommygun]

So will there be separate engines for each fuel type or do you just tweak the part settings while in the VAB?

[Starwaster]

I'm curious as to why you reduced the ISP of the engines to boost the thrust (I get the physics). The main advantage IRL of nuclear rocket design is the high ISP, is it just the burn time issue? Also any plans to have liquid core and gas core nukes? (even more ISP)?

Some thoughts:

Nuclear rocket Isp is based on propellant density and temperature. The only reason they have high Isp is if they use hydrogen which is the lightest of all the elements. LiquidFuel is way too dense to be hydrogen so the stock LVN had an Isp that was way too high.

As he said on the first post, the assumption is the fuel we're using a hydrocarbon, so an Isp of ... what was it, 850? That's way too high for something like RP1 / Kerosene. You won't see that in a solid core NTR unless you're using H2 like I said. You can use anything an a nuke btw, including methane, ammonia or even water. (methane and ammonia have some nice stats. I like using Ammonia in Real Fuels)

Edit: Ugh sorry for the redundancy... err...

Edited December 19, 2014 by Starwaster

[Kommitz]

Quick question and comment, and I apologize in advance if it is a stupid one (and no I haven't actually played this mod in a recent form (played the way old one). But I like nuclear rockets.

I'm curious as to why you reduced the ISP of the engines to boost the thrust (I get the physics). The main advantage IRL of nuclear rocket design is the high ISP, is it just the burn time issue? Also any plans to have liquid core and gas core nukes? (even more ISP)?

While the improved burn times are nice it's mostly just personal preference on my part, I think the tiny little nuclear rockets that can be built in stock KSP are just a bit too silly.

I'd also been planning to add LiquidHydrogen configs at some point and wanted them to be a proper improvement/alternative to the standard engines, which would be difficult if I'd kept the magical stock stats.

I think 570 Isp is still a significant enough improvement over most of the non-nuke engines so they feel like they have a place. Should work out around as cost effective as the standard nuke in career mode too, so long as my balancing attempts went right. I could use feedback on that though as I'm not too concerned about very efficient builds by the time I have nuke engines...

So will there be separate engines for each fuel type or do you just tweak the part settings while in the VAB?

I was thinking of providing different .cfg files that will just overwrite each other. The good thing is that .cfgs can contain multiple part configs, so I can just bundle the current variety, hydrogen variety or both together and they'll just be drag & drop to replace them with what you want.

[Virtualgenius]

The new Skylon Mod is using hydrogen as its fuel the dependency is the community resources pack here is a link if your interested http://forum.kerbalspaceprogram.com/threads/49756-WIP-R-E-L-Skylon-C2-Alpha-Released-FAR-config-broken-%2808-Dec-2014%29

[Darth Lazarus]

wow, Kommitz nice work so far with your nulcear rockets time to build a long range explroer to Eeloo with your engines

[PanWieldingMann]

I can't resist using these engines, they're on all of my 1.25-2.5 upper stages now.

[harlikwin]

While the improved burn times are nice it's mostly just personal preference on my part, I think the tiny little nuclear rockets that can be built in stock KSP are just a bit too silly.

I'd also been planning to add LiquidHydrogen configs at some point and wanted them to be a proper improvement/alternative to the standard engines, which would be difficult if I'd kept the magical stock stats.

I think 570 Isp is still a significant enough improvement over most of the non-nuke engines so they feel like they have a place. Should work out around as cost effective as the standard nuke in career mode too, so long as my balancing attempts went right. I could use feedback on that though as I'm not too concerned about very efficient builds by the time I have nuke engines...

I was thinking of providing different .cfg files that will just overwrite each other. The good thing is that .cfgs can contain multiple part configs, so I can just bundle the current variety, hydrogen variety or both together and they'll just be drag & drop to replace them with what you want.

I dunno, with best stock liquid fuel engine ISP being 390 and I assume significantly lighter than the nuclear engines you would have to have a massive craft size for it to make sense from a fuel efficiency standpoint. I often start wondering about even the stock "magical" LV-N's on medium size craft due to the major weight penalty they impose and that's with the 800s ISP.

I get that the denser fuels in "reality" mean a much lower ISP, but generally speaking the "raison de etre" for nuclear engines is the high ISP and correspondingly lower fuel fractions.

Anyhow I look forward to the engines that have the hydrogen based fuel params.

Also I'm wondering if the mod includes liquid or gas core nukes at all? (more ISP )

[Starwaster]

I get that the denser fuels in "reality" mean a much lower ISP, but generally speaking the "raison de etre" for nuclear engines is the high ISP and correspondingly lower fuel fractions.

except that the high Isp isn't because it's nuclear per se. It's because the propellant was entirely H2. Another benefit: it also means lighter stages overall.

[Synthesis]

While the improved burn times are nice it's mostly just personal preference on my part, I think the tiny little nuclear rockets that can be built in stock KSP are just a bit too silly.

I'd also been planning to add LiquidHydrogen configs at some point and wanted them to be a proper improvement/alternative to the standard engines, which would be difficult if I'd kept the magical stock stats.

I think 570 Isp is still a significant enough improvement over most of the non-nuke engines so they feel like they have a place. Should work out around as cost effective as the standard nuke in career mode too, so long as my balancing attempts went right. I could use feedback on that though as I'm not too concerned about very efficient builds by the time I have nuke engines...

I was thinking of providing different .cfg files that will just overwrite each other. The good thing is that .cfgs can contain multiple part configs, so I can just bundle the current variety, hydrogen variety or both together and they'll just be drag & drop to replace them with what you want.

I would like to see this as well--"Atomic Age rockets", which I think you've heard of, introduced me to the jump and I'm enjoying where it's going so far.

[LameLefty]

except that the high Isp isn't because it's nuclear per se. It's because the propellant was entirely H2. Another benefit: it also means lighter stages overall.

Gotta correct/add to this - you're right that the high ISP is/was due to the fact that the working fluid (e.g. the propellant) was hydrogen. But you have to remember the other big factor in real-world ISP: exhaust velocity. NERVA had insanely high exhaust velocity, and it it obtained that high exhaust velocity due to a really, really high energy flux to heat and expand the working fluid to those high velocities. Without something like VASIMIR (which hasn't even reached scales of the Timberwind NERVA tests), the only way to get those high exhaust velocities at the same mass flow rates to give good thrust is to use a nuclear thermal core.

So .... anyway, just read Kommitz's plan for the next update and I can't wait. I heart these engines so much.

Edited December 27, 2014 by LameLefty