[WIP] Real Scale Boosters

[NathanKell]

FWIW the Centaur in that drawing looks too short for its stated length. You might want to take the drawing into Photoshop and get the width in pixels of the Centaur on the 401 (known to be 3.048m) and compare it to the lengths, in pixels, then compute the meters.

[Kartoffelkuchen]

@NecroBones Don't worry, your dimensions are more accurate than mine. If you look, CCB is 32.46m long (engine nozzle-top probably) according to spaceflight101.com, mine is only 28.77m long. Overall, my Atlas V seems to be about 5m off. So you'll be more accurate than me here. I am working on the revamp of the Atlas V, and then the sizes should be much more accurate.

So don't worry, you seem to did everything right. Though your Centaur looks a little too long, but that's only guessing from the image. And the conical interstage adapter (on top of CCB) looks a little squished, if you compare it to real Atlas Vs.  Great job otherwise! :))

Edit: I only measured the length of CCB from top to bottom, without the engines. Length about 28.8m, so it's close what you calculated (~29m). Try adjusting the length of your Centaur, that should get the dimensions closer to the real one.

 

Edited January 22, 2016 by Kartoffelkuchen

[Phineas Freak]

Your math is correct. Breaking down the lengths we get the following approximate values:

1. RD-180: 3.6 m
2. RP-1 tankage: ~10 m
3. LOX tankage: ~19 m
4. Conical ISA: 1.6 m
5. Centaur ISA: 2.5 m (includes the RL10C-1 engine with a length of 2.2 m)
7. Centaur common bulkhead tankage: ~9.4 m
8. LPF: 12 m

Overall length: ~58.1 m, close to the standard 401 configuration (57.3 m). The tank lengths were calculated for an average 95% fill ratio.

Doesn't look different than an old replica of mine:

Spoiler

<IMAGE REMOVED BY USER>

Edit: Multi - ninja-ed...

Edited November 17, 2016 by Phineas Freak
Remove image link

[curtquarquesso]

Wow. I've been looking for a realistic Atlas for a while now. The OMSK Atlas was abandoned, @Kartoffelkuchen's Atlas was out of commission until earlier today, and @CobaltWolf's Atlas is awesome for stock-alike rockets, but not as good aesthetically when I'm looking to make super-realistic replicas. 

When I'm modeling and working on scale, I usually drag an image plane into my workspace, get a scale standard, and look at the planes orthographically and match the shape the best I can. I will say though, ULA doesn't have a ton of good orthographic drawings of Atlas out there. Very few and far between. 

Is there any way you could get the CCB tank color and texture more accurate? A lot of people make the texture look like orange insulation, when really it's a semi-shiny copper color. 

Keep it up. When this comes out, I'll try to make a rescaled config for stock and 6.4x scaled Kerbin. 

[Kartoffelkuchen]

OK, me again.

So, it seems the visible part of the Centaur attached to the rocket is too long indeed. Those 8.71m we can see on the illustration can be totally correct. Mine is a little too short, 8.1m instead of 8.7m.

 

Edited January 22, 2016 by Kartoffelkuchen

[CobaltWolf]

2 minutes ago, curtquarquesso said:

 @CobaltWolf's Atlas is awesome for stock-alike rockets, but not as good aesthetically when I'm looking to make super-realistic replicas.

#TRIGGERED

[Guest]

Are you going to put attachment points on it, or are the SRBs going to be attached radially?

[NecroBones]

27 minutes ago, Phineas Freak said:

4. Conical ISA: 1.6 m

5. Centaur ISA: 2.5 m (includes the RL10C-1 engine with a length of 2.2 m)
 

Yeah, this part looks pretty accurate to me too. I just made changes to the interstage and that part looks much better now (at least in Blender, I'll compile it into the game shortly). I'll rework the length of the Centaur a little, but I'll leave the CCB alone for now (though yeah, a more coppery color would be more accurate, I may try that too while I'm at it). At some point the RL10 might need some updating since for now I only have the bells sticking aft of the tank butt, and not turbopumps and the like.

 

EDIT: I love snow-days. I actually have some time to experiment with this, this afternoon.

Edited January 22, 2016 by NecroBones

[NecroBones]

OK, updated view. I reworked the interstage, and shortened the Centaur by 1.9m. Also sampled a color from a picture of the CCB. What's funny is that the texture has some fine-grained detail, but at this zoom level it looks like a solid color. I may need to add some color variation or banding or something.

 

[Probus]

Awesome, Awesome, Awesome!  Thanks @NecroBones for assembling another great mod!

[Phineas Freak]

14 hours ago, NecroBones said:

I may need to add some color variation or banding or something.

You can try to create a pattern for the RP-1/LOX interstage and the various structural adapters as seen on the following picture:

Spoiler

Notice the color differences between the parts that compose the overall CCB.

[NecroBones]

Yeah, I may work some elements in like that. There's been a lot of variation in overall color over the years apparently too, which is both a blessing and a curse.

It may end up being a multi-step process. The good news is I can always tweak it later too. What I've added so far is some subtle color variation:

 

[Guest]

5 minutes ago, NecroBones said:

Yeah, I may work some elements in like that. There's been a lot of variation in overall color over the years apparently too, which is both a blessing and a curse.

It may end up being a multi-step process. The good news is I can always tweak it later too. What I've added so far is some subtle color variation:

Maybe you could use the texture switch mod?

[NecroBones]

I ran into a little snag with the payload fairing + interstage on the 500 series Atlas V. I set it up so that the cylindrical interstage would connect to the Centaur first, as a decoupler. Then the fairing base "boat tail" would snap on over it. It's hollow, so I figured this should be OK (with my only real uncertainty pertaining to how it might affect aerodynamic occlusion). However... It wouldn't behave nicely in the VAB. It wouldn't allow a straight-sided fairing with the Centaur already there, even though there's about a meter of clearance on all sides. You would have to flare out the fairing another meter or so in radius before you could make a straight, vertical fairing above that. It's not making much sense to me.

 

So now I'm tempted to try making a decoupler/truss that you attach to the Centaur first, and then the entire interstage+boattail would snap beneath that as the fairing base. It would work more like the stock parts, so hopefully the procedural fairings would behave.

[liquidhype]

34 minutes ago, NecroBones said:

I ran into a little snag with the payload fairing + interstage on the 500 series Atlas V. I set it up so that the cylindrical interstage would connect to the Centaur first, as a decoupler. Then the fairing base "boat tail" would snap on over it. It's hollow, so I figured this should be OK (with my only real uncertainty pertaining to how it might affect aerodynamic occlusion). However... It wouldn't behave nicely in the VAB. It wouldn't allow a straight-sided fairing with the Centaur already there, even though there's about a meter of clearance on all sides. You would have to flare out the fairing another meter or so in radius before you could make a straight, vertical fairing above that. It's not making much sense to me.

 

So now I'm tempted to try making a decoupler/truss that you attach to the Centaur first, and then the entire interstage+boattail would snap beneath that as the fairing base. It would work more like the stock parts, so hopefully the procedural fairings would behave.

Are you making the Centaur interstage adapter and boattail as one single part? I'd suggest modeling them as two separate pieces, like it would have been assembled in real life. The interstage-boattail combo is pretty complex in real life. You should research the innards of it. It has a "seat" for Centaur.

The way I did it when I modeled my Atlas V HLV was to model the interstage adapter separately from the boattail. I gave the interstage a node on the bottom for attaching to the CBC, one in the middle for the Centaur seat (decoupler) and one node on top where the boattail would attach. Then the boattail would have 2 nodes, one on either side for the fairings.

[NecroBones]

10 minutes ago, liquidhype said:

The way I did it when I modeled my Atlas V HLV was to model the interstage adapter separately from the boattail. I gave the interstage a node on the bottom for attaching to the CBC, one in the middle for the Centaur seat (decoupler) and one node on top where the boattail would attach. Then the boattail would have 2 nodes, one on either side for the fairings.

 

This is what I did first, except it's using the procedural fairings, which don't seem to like having the centaur sitting right through the center of the boattail.

EDIT: I just tested the second method-- having the seat/truss act as a decoupler, and then a one-piece interstage with boattail and proc fairing.... same results.

Edited January 23, 2016 by NecroBones

[NecroBones]

Alright, for now I've put it back the way it was, with the interstage (decoupler) and boat tail (fairing base) as separate parts. Here's a screenshot showing how I had to flare out the proc fairing by 0.5m at the bottom before it would let me go straight up around the centaur. I can't make the fairing more narrow (so that the radius matches the boat tail) right from the start at the bottom in the VAB. Grr.

 

[NecroBones]

Centaur with a payload adapter (decoupler) attached.

 

 

Working on the SRBs, trying out a 552:

 

 

 

[VenomousRequiem]

Last time I checked, there was TweakScale support, no? But it was a little wonky... Maybe if you have actual tweakscale support you won't need to make any rescales! 

[NecroBones]

3 hours ago, VenomousRequiem said:

Last time I checked, there was TweakScale support, no? But it was a little wonky... Maybe if you have actual tweakscale support you won't need to make any rescales! 

Yep, there's TS support in there. The problem is that since so little of it corresponds to the normal stock/TS sizes, it's not always clear what each thing should be set to. I'm tempted to set everything to "free" scaling and let people scale it by whatever increments they want.

[VenomousRequiem]

26 minutes ago, NecroBones said:

Yep, there's TS support in there. The problem is that since so little of it corresponds to the normal stock/TS sizes, it's not always clear what each thing should be set to. I'm tempted to set everything to "free" scaling and let people scale it by whatever increments they want.

Yes! That would be wonderful! That way I can use this awesome mod in my non RSS installs! 

[billkerbinsky]

On 1/9/2016 at 6:02 AM, NecroBones said:

EDIT: Another thing to think about is that engine skirt extension. It looks like it starts in that collapsed position and then extends after stage separation? I could add a small animated toggle, but it wouldn't restrict when the engine can fire, I don't think.

Yes, the engine bell extension does that in flight (I guess the extra weight of the mechanism is less than the weight of a longer interstage).   For an example of this in KSP, see @Nertea's Cryogenic engines pack - the Ct10 'Chelyabinsk' is inspired by the RL10.   There are also deployable vacuum nozzles on a couple of the engines in his Kerbal Atomics pack.

A DeployableEngine plugin handles the animation.

 

 

[VenomousRequiem]

1 minute ago, billkerbinsky said:

Yes, the engine bell extension does that in flight (I guess the extra weight of the mechanism is less than the weight of a longer interstage).   For an example of this in KSP, see @Nertea's Cryogenic engines pack - the Ct10 'Chelyabinsk' is inspired by the RL10.   There are also deployable vacuum nozzles on a couple of the engines in his Kerbal Atomics pack.

A DeployableEngine plugin handles the animation.

 

 

Both of those engine mods are by Nertea... He's the guy to go to for extendable nozzles! 

[Kartoffelkuchen]

BDAnimation module lets you play an engine animation first, abd inly after animation is completed the engine is ignited.

[NecroBones]

7 hours ago, billkerbinsky said:

Yes, the engine bell extension does that in flight (I guess the extra weight of the mechanism is less than the weight of a longer interstage).   For an example of this in KSP, see @Nertea's Cryogenic engines pack - the Ct10 'Chelyabinsk' is inspired by the RL10.   There are also deployable vacuum nozzles on a couple of the engines in his Kerbal Atomics pack.

A DeployableEngine plugin handles the animation.

 

 

 

7 hours ago, VenomousRequiem said:

Both of those engine mods are by Nertea... He's the guy to go to for extendable nozzles! 

 

6 hours ago, Kartoffelkuchen said:

BDAnimation module lets you play an engine animation first, abd inly after animation is completed the engine is ignited.

 

Of course, this is all after I already made that part (and had it in the test download). For now it's just an optional animation, and the engine runs in either mode.