Convair NEXUS - super heavy Historical Launch Vehicle

[TiktaalikDreaming]

Had a bit more time and added (some of the) colouring and a few details like the thrust structure

[TiktaalikDreaming]

And some progress on the main engine.

[TiktaalikDreaming]

SLOWLY revamping the first stage.

I've started working on the ED Engine, aiming to use the same texture atlas as the plug engine.  And I haven't worked out a way of re-using texture space from the side panels for the two variants, with and without flaps.  But the 3d work is getting closer.

I did recently try out the new shader for the main tank, seeing it's reasonably described as industrial acres of sheet titanium welded into a bubble.  And it doesn't look too bad, although it needs tweaking some values to look right in game I think.

[TiktaalikDreaming]

I finally have a functional mechanism for the flap extension.  

Notes:
Flaps aren't textured, ditto for the extension arms.
Shell pieces are basically just block coloured plus AO
Heat Shield is not revamped.
Engine and control engines don't really function properly yet.

But it's getting prettier.

Glamour shot

 

[TiktaalikDreaming]

New plumes coming soon as well.  After quite some struggles wrangling part tools and unity.

I do need to reduce the control rocket plume length still.  But I also want to start looking at doing the long awaited resizing to 62.5% or 64% scale soon, preferably before finalizing the plumes.  EG: even now, those control rocket plumes could do with being thicker, but it's at 50% scale.  If I match them now, it'll still not look right at 62.5%

[TiktaalikDreaming]

I've been moving house, so pretty much zilch modding time for a while.  Just thought I should package the revamp bits if anyone wanted to take a peek.

https://github.com/TiktaalikDreaming/Nexus/releases

v1.9s will be pre-release revamp, using v2.0 when I get a usable craft revamped.

Note; because I'm rescaling, the revamp removes all the non-revamped parts.  This means all you can really do now is look at a half finished first stage and say "that's really big, pity I can't attach anything to the top without it looking stupid.".

I'd like to complete this revamp before heading on to fixing some other mods (Orion, cough cough).

[captinjoehenry]

Oh my this is aweomse!  Looking forward to this!

[TiktaalikDreaming]

I had some time today and got a basic Interstage modeled up.  Needs colliders, a bit of grunge and so on, but progressing for the first time in ages.

[TiktaalikDreaming]

and some second stage

 

[KAO]

I'm trying to use this mod in Realism Overhaul since it just got updated. What's the rescale factor to bring the size back to real size, and to bring thrust back to real world thrust? I'll try to get the config into the RO repo for future use.

[TiktaalikDreaming]

9 hours ago, KAO said:

I'm trying to use this mod in Realism Overhaul since it just got updated. What's the rescale factor to bring the size back to real size, and to bring thrust back to real world thrust? I'll try to get the config into the RO repo for future use.

Nice.

The numbers for masses, thrusts etc should be pretty consistent with the old RO config I did;

https://github.com/TiktaalikDreaming/Nexus/blob/master/Parts/RealismConfigs.cfg

As for rescale, I've been doing the revamped parts in full realism scale, then using rescaleFactor=0.625 in the config files.  So, changing that to 1.0 will set the size to full real scale.  Some of my old parts were modelled in all sorts of scale.  Also, the old version was 50% scale, rather than 62.5%, which is a more common kerbal scale.  The scale changes depending on what you mean by "since it got updated".  The released mod versions on spacedock and thus through ckan are the old mod, with some new models, but in the old 50% scale.  I wanted to work with just the new parts, and rescale, so I branched on git and this (https://github.com/TiktaalikDreaming/Nexus/tree/Revamp) is where I'm headed with the mod.  But due to the rescale in particular, I had to start working without the old parts cluttering things up.  (to help non-github initiated people along, I just tagged a new release, so it's easier to download the current state https://github.com/TiktaalikDreaming/Nexus/archive/1.9.0617.zip)

The rundown of masses I've been working from for the size-1(as in 1 million pound payload) Nexus is here https://drive.google.com/file/d/1qeqbGQ2tmweqUFORgtV9p9POJRbqYAbU/view?usp=sharing

The revamp branch is all just that one size craft so far.

[TiktaalikDreaming]

OK, derp.  I haven't been properly telling github to use the revamp fork when creating 1.9 releases.  1.9.0804 is the first actual revamp WIP release.  Consider it a 0.X type release.  

 

https://github.com/TiktaalikDreaming/Nexus/releases/tag/1.9.0804

Edited August 4, 2019 by TiktaalikDreaming
added link

[TiktaalikDreaming]

If you want the second stage engine, I was toying with the idea of splitting it, and some other nuke engines out as a separate mod, TD Advanced Propulsion Systems, TDAPS.   So the partly finished gas core engine is in a pre-release git repo, over here https://github.com/TiktaalikDreaming/TDAPS/releases

[TiktaalikDreaming]

It occurs to me after trying a first and second stage with that engine from my Dev tdaps repo that it doesn't fit.

So I guess I know what I'm working on next. That said, that engine has two modes, one that requires way more radiator than will fit in the fairing, so I did half know it wouldn't fit. That mode is the high ISP, low thrust, actively cooled version with several football fields of liquid helium radiator.

I'll be taking a lot of the above shadow shield things and moving them to neutron embrittlement land. And hoping that's enough without shortening the nozzle. But again, the nozzle is a high efficiency nozzle.

Original

Going to see if I can just pile things up on top of the shadow shield, drop the (probably unreralistic anyway) gimbal, and see just how much nozzle shortening I still need.

aka

Edited August 6, 2019 by TiktaalikDreaming
pics, cos posts don't exist without them

[TiktaalikDreaming]

A bit of work this weekend into a shorter Gas Core NTP* rocket. 

The rocket engine isn't done, but it's doen enough to check it fits between the first and second stages.  Mildly important.

So I ran a test flight.  Album here: https://imgur.com/gallery/cudaFlI

* NASA have started using the term NTP (Nuclear Thermal Propulsion) for what has traditionally been called Nuclear Thermal Rocket.  Thye might very well have taken the step due to possible confusion between Nuclear Thermal Reactor and Rocket, but I find myself constantly confused as I run several Network Time Protocol servers.  I will therefor persist in calling them "Nuke engines", NTRs, "NTP Rockets" or similar, even if the last is effectively a tautology.

[TiktaalikDreaming]

I've updated the release of TDAPS and the Short Gas Core is more complete now.  There's a mild discrepancy in the stack nodes on the base of the second stage, but I think that's an issue with the nexus stage, not the rocket.  There's a small gap, if you manually close that gap using the move tool, the engine fits (just).  I'll be updating the second stage stack nodes when I have time to figure what's gone weird there.

 https://github.com/TiktaalikDreaming/TDAPS/releases

Although, I seem to be missing the specular. 

But it now comes with bonus emmisive tied to the throttle;

[captinjoehenry]

Hi I have both of the mods installed from your experimental releases but only the nexus fuel tank shows up in even sandbox mode.

Found the problem

the downloads you have for the expirmental ones have assorted numbers after them.  But the model paths have none of the numbers on them

Edited August 17, 2019 by captinjoehenry

[TiktaalikDreaming]

4 hours ago, captinjoehenry said:

Hi I have both of the mods installed from your experimental releases but only the nexus fuel tank shows up in even sandbox mode.

Found the problem

the downloads you have for the expirmental ones have assorted numbers after them.  But the model paths have none of the numbers on them

In the paths?  I seem to remember this might be why I stuck with spacedock and manual zip files for releases.  It also confused me for ages with Taniwha's blender plugin to import mu files.  At some stage I'll need to make that saner. 

[TiktaalikDreaming]

I made a thing;

 

[TiktaalikDreaming]

And this other thing;

 

[captinjoehenry]

Very cool!

Any chance of a fairing for both the Nexus and the second stage?  As it would be nice to aero shield parts on lift off.  And the Nexus is an SSTO so a fairing for it does make sense.

Also an easy way to fix the git hub issue is to just make an upper folder called GameData and realese that in a zip.  That way you can just drag and drop without needing to rename the nexus folder

Edited August 22, 2019 by captinjoehenry

[TiktaalikDreaming]

1 hour ago, captinjoehenry said:

Very cool!

Any chance of a fairing for both the Nexus and the second stage?  As it would be nice to aero shield parts on lift off.  And the Nexus is an SSTO so a fairing for it does make sense.

Also an easy way to fix the git hub issue is to just make an upper folder called GameData and realese that in a zip.  That way you can just drag and drop without needing to rename the nexus folder

Those are planned. Agreed I've finished some tweaks on the interstage parts, in fact. My test craft are not looking very aerodynamic

[captinjoehenry]

2 hours ago, TiktaalikDreaming said:

Those are planned. Agreed I've finished some tweaks on the interstage parts, in fact. My test craft are not looking very aerodynamic

Thank god!  As it is trying to launch the Nexus without a fairing dies a horrible death due to drag.  It has so much drag it is totally unable to do SSTO stuff without me adding tweakscale to the interstage so I can reduce air drag.  The darn thing is so wide it has an obscene amount of drag XD

Also the retro rockets on the heat shield have more or less 0 margin.  I would recommend either increasing their power and or increasing the crash tolerance of the heatshield.  Because as things are firing the retro rockets at nearly the exact right second with a nearly empty tank gave me an impact velocity around 60~ m/s 

Edited August 22, 2019 by captinjoehenry

[TiktaalikDreaming]

2 hours ago, captinjoehenry said:

Thank god!  As it is trying to launch the Nexus without a fairing dies a horrible death due to drag.  It has so much drag it is totally unable to do SSTO stuff without me adding tweakscale to the interstage so I can reduce air drag.  The darn thing is so wide it has an obscene amount of drag XD

Also the retro rockets on the heat shield have more or less 0 margin.  I would recommend either increasing their power and or increasing the crash tolerance of the heatshield.  Because as things are firing the retro rockets at nearly the exact right second with a nearly empty tank gave me an impact velocity around 60~ m/s 

The main first stage tank is mostly a giant hydrogen balloon. Convair obviously thought drag concerns were secondary to surface area to mass ratios. The way no one has flown anything like it suggests they were wrong, but maybe it's a scale thing.

I normally actually have too much delta v at the end, which is just as bad and a bit more Kerbal. I doubt there's any good solution here except to add the potential for more solid fuel. Then a bit of trial and error can get out right for your game. At first I thought you were going to mention the retro rockets on the interstage, because I was just looking at their total absence. Which is one of those things I need to fix before adding fairings.

[captinjoehenry]

3 minutes ago, TiktaalikDreaming said:

The main first stage tank is mostly a giant hydrogen balloon. Convair obviously thought drag concerns were secondary to surface area to mass ratios. The way no one has flown anything like it suggests they were wrong, but maybe it's a scale thing.

I normally actually have too much delta v at the end, which is just as bad and a bit more Kerbal. I doubt there's any good solution here except to add the potential for more solid fuel. Then a bit of trial and error can get out right for your game. At first I thought you were going to mention the retro rockets on the interstage, because I was just looking at their total absence. Which is one of those things I need to fix before adding fairings.

That bigness and drag is why I mentioned the first stage needing a fairing   As it is designed as an SSTO even without a second stage.  As things are though it's obsenely draggy to the point of killing SSTO abilities.

As for adding more solid rocket fuel that's a decent idea.  I would say you can probably leave the retro rockets as is and just boost the impact tolarence to like 75 or 65 m/s as that's enough to cut it.  And I mean the Sea Dragon was designed for like a 100+ m/s impact and it's an equally huge rocket