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[WIP] Convair NEXUS - super heavy Earth Launch Vehicle


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This is really a place holder for discussion about a new set of parts I'm working on. (and so people have somewhere to ..... about stuff not working)

The Convair (Gen Dynamics) Nexus, a post Saturn design (that was never built) to send massive payloads into orbit. (http://www.astronautix.com/lvs/nexus.htm)

So far I've uploaded a working set of parts for the base 164 foot (at half scale) Nexus that was designed for orbiting a 1 million pound payload, and then returning to earth.

There's some placeholder textures wrapped on these now. Most are just texture swatches applied over the UV maps, but the first decoupler has an operating normal map, even if it is a bit unrelentingly black.

There's enough adapter/decoupler to connect from the nominally 150 foot (halved to 75f=~18m) all the way down to 3.75m aka size 3 parts.

Also to 5m and 7.5m or 60foot.

There will be (but isn't yet) secondary stages in 120foot and 70foot with some big gas core nuke rockets. These, again, will be large parts, for pushing other large parts across space. Not technically part of the "Nexus" but part of the development work done under the auspices of the nexus project. There's a multitude of designs, so not all will be represented. Clamping fairings suitable to loft an Orion WILL be among the parts, as that's why I started this thing in the first place.

And a second equivalent mod will eventually be released as full size. Once this is working and once the hanger extension mod works or has an equivalent.

ls4MRIx.png

DGarPP1.png

Download from Kerbal Stuff; https://kerbalstuff.com/mod/781/Super%20Heavy%20Boosters%20Historical%20-%20Nexus

Edited by TiktaalikDreaming
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First of all thank you very much for this mod, I am always happy and a little melancholic when I see mods from the golden age of space travel, not to forget that it would lower the part count for heavy launches drastically.

Ok now some feedback:

It would be nice to have a place to put in a probe core.

The main engine looks like a multi engine aerospike, but they point straight down instead of alongside the main cone.

6-aerospike_engine_after_test.jpg

Like this

A fairing would help a lot with testing crafts (and for playing around :D of course) I am not on a ksp capable computer for the next days, but I will try to upscale a stock fairing.

I found a rendering of the nexus on projectrho.com

ConvairSuperNexusDiagram.jpg

Here is the webpage of the artist:

http://william-black.deviantart.com/gallery/48294645/Real-Designs

I will continue playing around with this mod next week, I really like it.

Tanks again and keep up the good work

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First of all thank you very much for this mod, I am always happy and a little melancholic when I see mods from the golden age of space travel, not to forget that it would lower the part count for heavy launches drastically.

Ok now some feedback:

It would be nice to have a place to put in a probe core.

The main engine looks like a multi engine aerospike, but they point straight down instead of alongside the main cone.

https://web.csulb.edu/colleges/coe/mae/includes/projects/rockets/data/news_2008/images/aerospike/6-aerospike_engine_after_test.jpg

Like this

A fairing would help a lot with testing crafts (and for playing around :D of course) I am not on a ksp capable computer for the next days, but I will try to upscale a stock fairing.

I found a rendering of the nexus on projectrho.com

http://www.projectrho.com/public_html/rocket/images/artgallery/ConvairSuperNexusDiagram.jpg

Here is the webpage of the artist:

http://william-black.deviantart.com/gallery/48294645/Real-Designs

I will continue playing around with this mod next week, I really like it.

Tanks again and keep up the good work

Well, when you get to it, the fairings are now included, down to 7.5m diameter. 7.5m was the biggest fairings I had from the FASA pack, so that's where it became useful for me. I do intend a bunch of smaller fairings, and probably some "down to pattern of N times 3.75m diameter parts" fairings.

Projectrho, William Black, and myself are all getting our info from Mr Lowther's http://www.aerospaceprojectsreview.com and I am aware of their work. Making things function in KSP is a different beast than making a 3D model (although, there's clearly related work). And that's why the engines currently face directly down. I originally (http://i.imgur.com/BA6qghy.png) had them facing along the plug. This introduced some issues in KSP that I'm still looking at correcting for, but I basically wanted to get the thrust numbers and direction correct before revisiting the angles for the rocket nozzles. I DO want to go back to that, in my opinion it looks awesome. But KSP thrust direction is the same as the visual effect direction, independent of any other bits, so there's issues with this. :-)

Oh, and the new heat shield with integrated retro rockets now also has integrated probe core functions.

- - - Updated - - -

Is it a massive truncated aerospike with integrated Airbrakes?

That pretty much describes the Nexus booster. Originally planned to be a 50m diameter, recoverable first stage capable of getting 1,000,000 lbs (450tonnes) into orbit.

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Awesome work. Is it even possible to make a practical payload in KSP to utilize this? I'm really hoping to see more concept rockets such as this.

Depends on the ISP. If it has low values, most of the payload will be fuel.

Another thing is modded games such as Real Solar System. Having huge rocket engines is actually a big help.

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-snip-

Some more info on that thing i found:

That's a truncated aerospike engine, albeit a freaking huge one. It had only 4 flaps and they did not extend as far as yours. It had 4 blocks of 6 thrusters in addition to the aerospike which served as verniers. I see you have those modeled in already. ALso from what I can tell, the nozzles surrounding the aerospike were angled in, but not flattened as I usually see them, which is a bit unusual. Why the giant aerospike is hollow remains a mystery to me.

image for additional reference:

convair_nexus_ssto_by_william_black-d77puy9.jpg

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Some more info on that thing i found:

That's a truncated aerospike engine, albeit a freaking huge one. It had only 4 flaps and they did not extend as far as yours. It had 4 blocks of 6 thrusters in addition to the aerospike which served as verniers. I see you have those modeled in already. ALso from what I can tell, the nozzles surrounding the aerospike were angled in, but not flattened as I usually see them, which is a bit unusual. Why the giant aerospike is hollow remains a mystery to me.

image for additional reference:

http://fc01.deviantart.net/fs70/f/2014/155/4/8/convair_nexus_ssto_by_william_black-d77puy9.jpg

The flaps were actually for control, not braking, and I know I have them angle out more than the drawings, but that's the angle used by KSP's aerobrakes and I'm not particularly confident messing with that just yet. They also provide reality braking stopping power, just like KSP's aerobrakes.

And there were between 4 and 12 of them.

So, to model this, there's 12 shell parts that can be either a plain outer shell or a flap. There were actually two types of flap as well, the other being pretty much the whole side panel. I have that modelled in blender, but not moved over to Unity yet. So it's just plain panel or the shaped aerobrake so far. I wanted to get the pistons working before fiddling with more than one flap type.

The aerospike/plug system used 60 rocket nozzles instead of 10 or so, so there was less need to approximate a match to the cone using flattened nozzles. The aerospike is hollow because it's massive (with the weight to go along with that), and in an atmosphere, air passing through the hollow cone would help to provide a partial barrier and make the truncated plug act like a much longer spike. I don't have any firm details on the air flow through the cone on the Nexus, and I don't know if that was part of the design, but it seems to match. It seems like the saner way to build a very large aerospike.

As I said before, I will be re-angling the rockets. I want to get the visual effects right, then after I have that, run some maths on how much that angling (in my estimation of how KSP works) will affect the thrust, and see if that holds true or not. Then adjust total thrust again.

The control rockets are in blocks of 6, each block has 400,000 lbs thrust, which is out of step with William Blacks notes, so I'll need to double check my numbers. Maybe it was 400,000 lbs per nozzle, which would be 2.4Mlb, and about the 8M he's assigned to the controls. He's been commenting on my dev work over in the G+ KSP group, so I'll bug him as to where those numbers come from.

Of course, this is KSP, so you can add as many as you want, so 3 at a minimum to be able to angle any which way, and up to as many will fit. they're normal rockets though, so they suck a bit at low altitude.

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-info snip-

Doing some number crunching on the data I found, the control rockets should output 2,000,000lb thrust per block, which is ~333,333lb thrust per nozzle (but that doesnt matter because they're so comparatively small that one effect & thrust transform will work). In regards to angling engines & thrust, my suggestion would be to rig the particle effects from the nozzles but tuck a single thrust transform up in the aerospike nozzle. That makes the thing act like a single engine (as it presumably would IRL).

- - - Updated - - -

So what exactly is the purpose of something so massive, is it to loft entire interplanetary missions in one shot, put multiple refineries worth of fuel into orbit?

Yes. It was theoretically supposed to throw an entire Constellation MTV mission (or rather the equivalent at the time) into orbit at once.

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So what exactly is the purpose of something so massive, is it to loft entire interplanetary missions in one shot, put multiple refineries worth of fuel into orbit?

Originally a combination of single launch Mars mission or cutting down the multiple launches needed to build and supply a permanent moon base.

- - - Updated - - -

Doing some number crunching on the data I found, the control rockets should output 2,000,000lb thrust per block, which is ~333,333lb thrust per nozzle (but that doesnt matter because they're so comparatively small that one effect & thrust transform will work). In regards to angling engines & thrust, my suggestion would be to rig the particle effects from the nozzles but tuck a single thrust transform up in the aerospike nozzle. That makes the thing act like a single engine (as it presumably would IRL).

Now that I re-look, it's 2Mlbs per block for total of 8. And 24Mlbs for the main rocket. Although I'll keep the stack of 6 thrust transforms matching the nozzles. But it seems I've underestimated them by a factor of 5, so I'll be beefing up the flame a bit.

Edited by TiktaalikDreaming
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I'd suspect the flame from this would have been quite beefy, to say the least.

Did they intend to pad launch this monstrosity?

There were concerns about noise. :-D

Towed barges were considered and so on. The "Likely acceptable in residential areas" (115db) distance was only 20 miles though. Closer than I would have thought.

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I have a working set of decoupler ring adapters for the Nexus, all the way from the 75 foot top diameter (a bit under 23m) down to 3.75m aka size 3 stock pieces. Although, the textures (actually, the normal maps) are wonky.

And I intend to split up the big long one that takes the diameter from the top of the retro rocket section (at 60foot) down to 7.5m. 60 foot is half size for the biggest Nexus second stage, and 7.5m is the largest diameter I had from the FASA mod.

But as it stands, there's 3.75m, 5m, 7.5m and 60 foot (18m) options. I'm going to clean up the normals and upload later.

SAS on "prograde" using the airbrakes over-corrects by massive amounts, and then over-corrects it's correction for that, etc. So I recommend control fins of some sort that will still be there when you attempt re-entry.

screenshot1042.png

screenshot1053.pngscreenshot1056.png

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I have a working set of decoupler ring adapters for the Nexus, all the way from the 75 foot top diameter (a bit under 23m) down to 3.75m aka size 3 stock pieces. Although, the textures (actually, the normal maps) are wonky.

And I intend to split up the big long one that takes the diameter from the top of the retro rocket section (at 60foot) down to 7.5m. 60 foot is half size for the biggest Nexus second stage, and 7.5m is the largest diameter I had from the FASA mod.

But as it stands, there's 3.75m, 5m, 7.5m and 60 foot (18m) options. I'm going to clean up the normals and upload later.

SAS on "prograde" using the airbrakes over-corrects by massive amounts, and then over-corrects it's correction for that, etc. So I recommend control fins of some sort that will still be there when you attempt re-entry.

1) It would be better to create one standard decoupler and create Tweakscale sizes for it instead of creating 5-6 parts on top of the several decouplers from other mods.

2) I'm sure there's an option to limit the airbrake's response time.

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1) It would be better to create one standard decoupler and create Tweakscale sizes for it instead of creating 5-6 parts on top of the several decouplers from other mods.

It might be better that way, but that assumes tweakscale. As a general rule of thumb, I don't create mods that are reliant on other mods.

2) I'm sure there's an option to limit the airbrake's response time.

Yep, I haven't messed with it yet though. I think what I need is beefing up the speed of response, but I just haven't looked at that yet. I also don't want to make it too fast, the size suggests it shouldn't be able to react as fast as a smaller system.

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Quick update on status. Too busy at work to upload anything, but I've messed with the flaps, so they open to a lesser angle and faster, without being silly about it.

I've built some second stage. Just one option so far, the 120foot diameter tank with 2x6MpT Gas Core nuke engines. Messing around to see how that works.

I've wedged in the reflective shader and found metal merchants with images to get the right colours for the titanium and stainless bits of the main tank.

Upload will probably wait until tomorrow.

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Depends on what's involved. I haven't been using realism overhaul, so I'm not familiar with what's involved. I have a significant collection of the numbers for such things as correct fuels etc. At the moment I've based fuel amounts on the weights of proposed fuel loads of LH and LOX, which means of course that there's less generic Kerbal liquid fuel than the shape/size would indicate. But then I used Convair's numbers for ISP as well, so that sort of balances out.

- - - Updated - - -

I got distracted by making logos and agencies. But the updated v0.7 is now uploaded.

It now has the reflective shader dll packed in. If you don't like the reflective surfaces, just remove the dll. If it's not there, I don't think it'll do anything. This is very much a release requiring the old version be deleted first. The folder structure has changed, so if you don't remove the old one, both will be loaded, and the game will do it's own choosing about which part is which, and which takes precedence.

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