What is the purpose of the Nuke engine..

[Wingnutt]

Considering the investment in science to get JUST it.. it seems to be more or less pointless.

Its abnormally long which frustrates construction.

I intended to use it once in orbit but its performance seems quite lackluster, low thrust and not particularly good economy. it seems like in any situation you could use it, there is always a better option.

Does it fit a specific niche? what is the best use for it?

[Starhawk]

I intended to use it once in orbit but its performance seems quite lackluster, low thrust and not particularly good economy.

It has by far the highest ISP of any engine other than the ion engine.

While it's twr is low, the efficiency makes clusters of these ideal for use as high mass/high delta-v transfer stages or tugs.

Happy landings!

[sal_vager]

Also it is important to know that it uses liquid fuel only, no oxidiser, so if you use conventional tankage you will have an excess of oxidiser mass that just robs you of performance.

Remove the excess oxidiser or use the aviation tanks instead.

(Cue calls for LF only rocket tankage and suggestions to use (insert addon here))

[Gaarst]

Try getting a 10000 m/s dV ship weighing no more than 20t. Only solutions are Nuke or "Dawn" ion engine (which has 30x less thrust).I don't know if a 20t ship powered by a nuke has exactly 10k dV and that's not the point.

[Wingnutt]

Looks like I was using the wrong fuel tanks!!!

[Sharpy]

Yep, hauling all that oxidizer around pretty much nullifies the benefits. Even LF/Ox tanks with oxidizer removed make it barely break even with best LF/Ox engines. But put it on MK3 LF Fuselage Long, add a second stage with it on the bottom of three MK1 LF fuselages, and watch the resultant dV!

[Tex_NL]

The stock options in LF only tanks is extremely limited. If you're not adverse to using mods you should take a look at FuelSwitch. It enables you to cycle all tanks between LF/Ox, LF only and Ox only.

[MarvinKitFox]

....and not particularly good economy...

Yep. uhu. whatever you say, bub.

[SmashBrown]

High efficiency interplanetary transfer engines! Also, QFT:

Also it is important to know that it uses liquid fuel only, no oxidiser, so if you use conventional tankage you will have an excess of oxidiser mass that just robs you of performance.

Remove the excess oxidiser or use the aviation tanks instead.

(Cue calls for LF only rocket tankage and suggestions to use (insert addon here))

[peachoftree]

I believe that interstellar fuel switch applies itself to all LFO tanks, but that might be one of my other 90+ mods I have installed

link: http://forum.kerbalspaceprogram.com/threads/117932

[Norcalplanner]

I believe that interstellar fuel switch applies itself to all LFO tanks, but that might be one of my other 90+ mods I have installed

link: http://forum.kerbalspaceprogram.com/threads/117932

I know that NecroBones now bundles Interstellar Fuel Switch with Fuel Tanks Plus, and I'm enjoying it immensely. He also now has multiple skins for FTP tanks which can be changed via tweakables in the VAB.

Clean white 2.5m rocket tanks filled with only LF for use with LV-Ns and the Quadnuke from MRS? Sign me up, please. ;-)

[peachoftree]

I know that NecroBones now bundles Interstellar Fuel Switch with Fuel Tanks Plus, and I'm enjoying it immensely. He also now has multiple skins for FTP tanks which can be changed via tweakables in the VAB.

Clean white 2.5m rocket tanks filled with only LF for use with LV-Ns and the Quadnuke from MRS? Sign me up, please. ;-)

It's the greatest for nuke + RAPIER spaceplanes

[LordCorwin]

It adds a good amount of delta-v with a reasonable amount of thrust.

You would say this also is provided by an Ion engine. Fine. But what if you're reaching a planet, a small body, and you need to orbit it? You need to reduce speed quickly. This cannot be provided by the Ion engine, and if the body is too far away from Kerbin, doing it with usual propellants would be costly.

But remember to remove all the oxidant from the tank, as it is not used.

Edited August 22, 2015 by LordCorwin

[Evanitis]

Its abnormally long which frustrates construction.

Design tip: put the payload and the interplanetary stage upside down at the top of the rocket, so the nuke points upwards at launch. Than it's sleek shape becomes a merit.

[Halsfury]

You quite literally need a big orange tank to draw fuel from or more to make the nuclear engine viable.

When 1.0 first came out I posted this article in tutorials concerning the fuel efficiency of stock upper stage engines.

With the advent of 1.0 the NUK only uses liquid fuel so the efficiency is marginally greater than the data screen tells you (since the rocket is lighter), that being said it's easy to forget to remove the oxidizer from the nuclear stage

http://forum.kerbalspaceprogram.com/threads/119333-Choosing-the-right-rocket-engine-for-greatest-efficiency-in-1-0-and-up

[Red Iron Crown]

You quite literally need a big orange tank to draw fuel from or more to make the nuclear engine viable.

Share your math, please. The LV-N starts outperforming the LV-909 at a bit under 5t of propellant according to my calculations (or a little more than one long 1.25m tank). Using LFO tanks with oxidizer tweaked out is bad for performance, use the LF-only tanks instead.

[Edax]

With stock parts, as I understand it, you need at least 2 LF size 1 tanks per LV-N to outperform LFO engines. Generally 3 LF tanks and 1 LV-N with various spacecrafts bits on it will give you about 4000 delta-V without staging.