Convair NEXUS - super heavy Historical Launch Vehicle

[TiktaalikDreaming]

Migrating from a dev thread regarding this, as many parts are now releasable.

Development version (consider this very beta): https://github.com/TiktaalikDreaming/Nexus

Release Versions: http://spacedock.info/mod/147/Super%20Heavy%20Boosters%20Historical%20-%20Nexus

IMPORTANT

Version 2.0+ is a complete revamp.  The parts are to 62.5% scale not 50%, and there's various other adjustments as well.  Installing v2 when you have a v1 install will cause the old "ships not loaded" messages and disappearing craft that had old parts.

Assumes but does not require Community Tech Tree (Creative Commons Attribution-NonCommercial) by Nertea. http://forum.kerbalspaceprogram.com/threads/100385-Community-Tech-Tree-2-0-last-updated-03-05-15?p=1546633#post1546633

Recommends (has modulemanager config for) Community Resource Pack by Rover Dude/USI. http://forum.kerbalspaceprogram.com/threads/91998-1-0-4-Community-Resource-Pack-04-3-2015-07-06?highlight=community+resource

Remaining components are licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Significant thanks need to go to Scott Lowther of up-ship.com/Aerospace Project Review and his work with the Nexus and related topics. And to the mob of very useful people in the KSP G+ Community. And to Winchell Chung in particular for providing the impetus to mod the hell out of Kerbal.

The Nexus booster is a massive squat booster rocket designed by Convair (General Dynamics) to get very large payloads into orbit and beyond. This mod is a replica at half scale (Kerbals are small, and their planet is small) of the base Nexus design.

It was designed to get a million pounds (~450 tonnes) into orbit, and then return and be mostly re-usable. This version is designed for 1/8th of the weights/thrust of the original, to match the half scale.

(from up-ship.com, where all the good info is)

Descent was controlled (but not really slowed) by big flaps. So side pieces are available as either flaps or static walls. You'll need 12 all up. Most representations have four flaps but versions with 12 were also investigated. Any mix of 12 pieces of either flap or static wall for KSP. As yet, there's only the one style of flap, but I always intended to produce both types that are detailed in Convair documents, and have had Blender models for both since the start. I just got these developed more as they look better than the whole panel and because I needed a test case to learn how to build aerobrakes in KSP.

At the last minute (I find just before the 1km altitude mark is best) forward facing solid rockets are fired that slow the descent and break the water surface tension and churn the water. This may have been optimistic, but probably would have worked as the forward shell/heat shield was sacrificial. A combination of this plus arrays of chutes was investigated but for some reason Convair decided to go with just the retro rockets. It apparently weighed less. Due to being lazy with determining re-entry points, I tend to add chutes. The retro rocket solution ain't so good landing on rock either.

Second stages so far are 35 foot and 60 foot hydrogen tanks with gas core rockets. So far there's 3 sizes, matching the 3 sizes used for the Convair 70 and 120 foot second stages. At 1/8th of 6 million pound thrust, and 4 and 3, it's easier to just refer to them by the original thrust grades. Gas Core Nuclear Thermal Rockets (GCRs) don't work well below a 1meter internal radius apparently (according to some studies around '98), so I'm being optimistic and saying Kerbals can make them a bit smaller. The 3MpT engine has an outside radius of 1m, so it's not too far off reality. The GCRs, as represented in this mod, are moderately optimistic. As yet, humanity hasn't managed to solve some fairly critical issues around instability of the containment vortex that stops the gaseous fission reaction from shifting and impacting things and then exploding.

In KSP terms, be aware these rockets are both generators and alternators. As the whole engine is mounted on a gimbal, they can gimbal a lot. Their atmospheric curve is highly punishing for using them in an atmosphere. (Kerbals don't seem to care as much about the radioactive and toxic exhaust, but reduced Isp is bad). They require a new resource, "BlutoniumTetraflouride", which is the reactor fuel. Some is expended. You'll get quite a bit of flight on the included fuel. They also explode easily. Not from their own operation, but just try not to bump them into things.

My original GCRs had a long slow build up and shut off time. Much like the jet engines, throttle response was slow. This is a result of my expectations of the engineering issues around building toroidal vortexes strong enough to hold a gaseous fission reaction. But in testing attempts to land on the Mun, it became clear that I just couldn't work a successful landing with the exaggerated throttle response lag. So this edition has that "feature" removed. It's likely to be re-applied later. But I'll be doing a bit of research into what that lag should be. In the end case, either the rockets won't have lag, or they will and you'll be best off with some fine control secondary landing rockets.

Various shots, with various stages of completeness

 

And parts in VAB

 

 

Edited May 24, 2020 by TiktaalikDreaming
v2 release

[_Augustus_]

Interesting.

[SmashBrown]

Can we have more pics please?

[TiktaalikDreaming]

More pics added to OP. After some fscking about. The moment I posted this I ceased to have any spare time. :-/

[SmashBrown]

More pics added to OP. After some fscking about. The moment I posted this I ceased to have any spare time. :-/

It happens. Thanks!

[KAO]

will a realism overhaul config be happening?

also, please PLEASE a config for just stock fuel, the requirement of exotic fuels makes the engines useless by themselves, and makes me wonder why they're their own separate part

Edited August 21, 2015 by KAO

[TiktaalikDreaming]

will a realism overhaul config be happening?

also, please PLEASE a config for just stock fuel, the requirement of exotic fuels makes the engines useless by themselves, and makes me wonder why they're their own separate part

I'm a bit unaware of what is required for a realism overhaul.

The main engine is it's own part as there will be options. Including a 30M lbT ablative expansion plug engine.

[TiktaalikDreaming]

will a realism overhaul config be happening?

Just had a look at Realism Overhaul. 'Tis quite a complex beast. So my answer at the moment is "not yet". I'd need to have a fairly serious look at what all the new values are. Some are fairly obvious, some less so. And some I won't have data for.

BUT, to resize to match RO, all the values for mass, thrust etc in my standard configs are taken direct from Convair's notes via Aerospace Projects Review (Scott Lowther). I took all the sizes and divided by 2 and masses (and thus volumes of liquid, aka fuel units) and divided by 8. The meshes in the first batch of parts were actually full size. In the configs for (say the main tank) you'll see rescale is set at 0.5. But I quickly found that it doesn't fit in the hanger. So I looked at how FASA worked things and discovered their stuff is basically half scale. And thus the half size, and eighth mass/thrust edition of the Nexus was born.

I will have a look at RO conversion, but not until I've finished a few other parts. I specifically want the NTRs to have a progression from solid, solid-water moderated, quartz incased gas core, before the open cycle gas core currently in the mod. And main engine variants, basically a couple of sizes of expansion deflection rockets with a framework to attach them.

[TiktaalikDreaming]

Working on the ED rockets for the next update. Hopefully be the end of the weekend. Because then I go tramping around NZ without internets for 3 weeks. (it's a ....ty life, but someone's gotta live it)

Anyway, 3-d model just about done for the L-30 AH 30 million pound expansion deflection rocket.

[TiktaalikDreaming]

3-D model now a part. I've been messing with different ways of using an ablator resource for the ablative cooling of the engine nozzle. I think it's going to come down to just a propellant at low proportions.

And, with RealPlume;

[MaverickSawyer]

Any chance of a low-resolution version for those of us with more... modest computers? I had to remove the pack due to severe lag and crashing issues. (Probably not the cause of the crashes, but still...)

[TiktaalikDreaming]

Any chance of a low-resolution version for those of us with more... modest computers? I had to remove the pack due to severe lag and crashing issues. (Probably not the cause of the crashes, but still...)

That's pretty easy to do in Unity actually. I need to juggle a few things to match past post-unity juggles. Some of the textures are largish, but none are huge. The killer I think would be that the 3D meshes are high poly meshes. If your PC is struggling, it may be more the detail in the 3D objects than the rez of the textures. You could test by loading the mod up and killing all the texture files. That'd be mostly .dds files, but there's probably a few left-over png or tga etc files. It'll look like either a white plaster molded object or an unshaded bright purple horror. But, it'll determine if it's the textures or something else.

It may also be the reflective shader. You could probably test that simply by removing the dll for it. Unfortunately there's a few things that hammer the system, and they all do it slightly differently.

Sorry about that. I have trouble telling as my PC is over-specced for KSP. Esp on the graphics side of things. Although that doesn't save me from the 3.X GB 32 bit limitation, except when I'm running under linux, but there's no Unity editor for linux, so I do all my dev on Windows. But still, I notice no slow down, but it makes it tricky to know when others might.

Edited August 22, 2015 by TiktaalikDreaming
appology added

[_Augustus_]

When 1.1 comes out and I can install every mod I want I will download this. But for now it's too big.

[TiktaalikDreaming]

When 1.1 comes out and I can install every mod I want I will download this. But for now it's too big.

I think that's pretty much what NASA said.

[Motokid600]

When 1.1 comes out and I can install every mod I want I will download this. But for now it's too big.

Don't get your hopes up on that one.

[_Augustus_]

Don't get your hopes up on that one.

I want ShadowWorks, FASA, USI, Tantares, SSTU, OPM, Scatterer, and AVP Interstellar.

I can run all that in 1.1 without crashing, right?

[Motokid600]

Should work fine, but you still have to tread lightly with 64bit. Ive been on Linux for a long time and you absolutely cannot haphazardly throw in mod after mod. Your install becomes a house of cards. One incompatibility or if one mod bugs out you will crash or worse. Corrupt.

With the mods you want there you should be okay. But iirc Scatterer is still buggy so you gotta watch. I play with the debug window open ALOT just take make sure everything runs smooth and I'll tell ya. It never does. There is always an error being thrown. Sometimes it's detrimental sometimes you don't notice any performance impact.

So with 64bit you trade having to dodge the 32bit memory limit with trouble shooting mod compatibility. Lol because you say it now "oh I only want to run with these mods." But very soon your like "I think ill take that one... And this. Oh gee gotta have that one!" Like a kid in a candy store. It's nice. Really nice but you can very easily go overboard. So tread lightly and be smart about it. Read up on every mod you install and read the last few pages of the thread to see what everyone is talking about if there's any on going problems.

Edited August 22, 2015 by Motokid600

[MaverickSawyer]

That's pretty easy to do in Unity actually. I need to juggle a few things to match past post-unity juggles. Some of the textures are largish, but none are huge. The killer I think would be that the 3D meshes are high poly meshes. If your PC is struggling, it may be more the detail in the 3D objects than the rez of the textures. You could test by loading the mod up and killing all the texture files. That'd be mostly .dds files, but there's probably a few left-over png or tga etc files. It'll look like either a white plaster molded object or an unshaded bright purple horror. But, it'll determine if it's the textures or something else.

It may also be the reflective shader. You could probably test that simply by removing the dll for it. Unfortunately there's a few things that hammer the system, and they all do it slightly differently.

Sorry about that. I have trouble telling as my PC is over-specced for KSP. Esp on the graphics side of things. Although that doesn't save me from the 3.X GB 32 bit limitation, except when I'm running under linux, but there's no Unity editor for linux, so I do all my dev on Windows. But still, I notice no slow down, but it makes it tricky to know when others might.

I guess I should have been a little more clear with my request... I have no problems with textures, but my eyes bugged out at the level of detail on the meshes. If you could reduce the poly count, that would make this viable. Stuff like the internal structure on the first stage tank could probably be one of the first to go...

[TiktaalikDreaming]

I guess I should have been a little more clear with my request... I have no problems with textures, but my eyes bugged out at the level of detail on the meshes. If you could reduce the poly count, that would make this viable. Stuff like the internal structure on the first stage tank could probably be one of the first to go...

Ah, yeah. I was thinking about this. Polygon-wise, I suspect I can cut down a lot on the main engine. I was always intending to do a minimal version of the rocket nozzle in play and never got to it, so it's actually the same 3-d object for the main engine as the control rocket. Except, instead of 6 of them, there's 60. At 9,752 tris (triangle polygons, all polygons are converted to tris for Unity) each. I was all, "oh yeah, that looks nice, but I should change it later", and never got around to it. I suspect if you delete the main engine part, it loads and behaves fine, even if it'll never get into orbit.

[TiktaalikDreaming]

Ah, yeah. I was thinking about this. Polygon-wise, I suspect I can cut down a lot on the main engine. I was always intending to do a minimal version of the rocket nozzle in play and never got to it, so it's actually the same 3-d object for the main engine as the control rocket. Except, instead of 6 of them, there's 60. At 9,752 tris (triangle polygons, all polygons are converted to tris for Unity) each. I was all, "oh yeah, that looks nice, but I should change it later", and never got around to it. I suspect if you delete the main engine part, it loads and behaves fine, even if it'll never get into orbit.

Try replacing the PlugEngine part with https://www.dropbox.com/s/876rpyikvc3d3wq/PlugEngine.zip?dl=0

That's a lower poly rocket for the 60 nozzles around the main plug. I intend to replace the over enthusiastic current version with this shortly. Just nutting out some issues with the giant L-30 AH engine of doom.

[TiktaalikDreaming]

v1.0.4 uploaded. This has a lower poly count for the main plug engine and a new engine.

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[TiktaalikDreaming]

Now available through CKAN. Yay!

[TiktaalikDreaming]

My (fairly limited) dev time will now be split between this and the Orion mod.

That said, my next "orion" update will be adapters to add Orions on top of the Nexus. Which, ultimately, was my starting point for working on the Nexus.

Stuff to still do for the Nexus;

Realism Overhaul compatibility

More NTRs. Partly to fill in remaining second stage options, and partly to provide parts for the science nodes leading to Gas Core NTRs. And tidy up those extra fuel tanks and stuff for second stages.

The other Nexus sizes. The mod so far is basically the smaller of the two main Nexus sizes proposed.

If there's stuff you think is needed, not on that list, let me know.

[MatterBeam]

My (fairly limited) dev time will now be split between this and the Orion mod.

That said, my next "orion" update will be adapters to add Orions on top of the Nexus. Which, ultimately, was my starting point for working on the Nexus.

Stuff to still do for the Nexus;

Realism Overhaul compatibility

More NTRs. Partly to fill in remaining second stage options, and partly to provide parts for the science nodes leading to Gas Core NTRs. And tidy up those extra fuel tanks and stuff for second stages.

The other Nexus sizes. The mod so far is basically the smaller of the two main Nexus sizes proposed.

If there's stuff you think is needed, not on that list, let me know.

I can help with RO/ Real Fuels compatibility.

[TiktaalikDreaming]

I can help with RO/ Real Fuels compatibility.

Cool.

I'm not sure exactly what needs changing, especially with engines, but I do have all the real world values. All the scales I've used are 50% (1/8th masses/thrusts/etc) of the Convair values where it was useful. But once into RO, I also have fuel residual numbers and so on.