[WIP] Real Scale Boosters

[Phineas Freak]

@NecroBones for the Atlas V 500 interstage, you can break it down into two parts:

1. A straight ISA that will have a normal attachment node and a decoupling node for the Centaur.
2. The conical ISA that will have the fairing base. This will attach at the normal attachment node of the ISA.

For a single part: prioritize the fairing action in the part.cfg and use the right - click menu for the Centaur to decouple.

Edit: do you have plans for other launchers? Titan has not been touched by anyone (i think)...

Edited January 20, 2016 by Phineas Freak

[Kartoffelkuchen]

I might remember from when I was working on the first version of the Atlas V, that all CCentaur's on Atlas Vs were white (don't know about 5xx missions how it was there). Centaur with insulation were used on the first few Atlas Vs maybe and were previlously used with insulation on Atlas III. 

 

Also, Centaur has helium bottles and spheres for RCS propellant, the number of them increases as longer the missions are, on a side note.

 

I still have no idea how you can just work on soo many things and finish them so fast.

[Phineas Freak]

Depending on the Centaur version, it used different ways and materials for insulation: early Centaurs used detachable fiberglass panels with white foam insulation. Starting with Atlas II and III, Lockheed Martin used orange insulation (like the one used on the STS ET) until some time around 2005 where they started using a white paint cover to protect the payloads from foam particles and improve the boiloff rate.

All Centaurs today use the white foam version regardless of the Atlas booster that are mounted on.

[Delta_8930]

5 hours ago, Phineas Freak said:

Edit: do you have plans for other launchers? Titan has not been touched by anyone (i think)...

Check out Liquidhype's Real Scale Launch Vehicles

Edited January 20, 2016 by Delta_8930

[NecroBones]

8 hours ago, NathanKell said:

Yeah, was just wondering if the 5xx series were left unpainted orange and the 4xx were painted.

Yeah that's a good point. I may have to google it a bit more. Most of the photos of the centaurs I've been looking at are showing just the centaur by itself (because I was trying to look at engine placement and the like).

 

5 hours ago, Phineas Freak said:

Depending on the Centaur version, it used different ways and materials for insulation: early Centaurs used detachable fiberglass panels with white foam insulation. Starting with Atlas II and III, Lockheed Martin used orange insulation (like the one used on the STS ET) until some time around 2005 where they started using a white paint cover to protect the payloads from foam particles and improve the boiloff rate.

All Centaurs today use the white foam version regardless of the Atlas booster that are mounted on.

OK that's good to know. I knew at least some of the more recent pictures were showing white, so I figured I'd do that one (at least for now). If that's what they're using on all of them now, then that's a good choice.

 

 

6 hours ago, Phineas Freak said:

@NecroBones for the Atlas V 500 interstage, you can break it down into two parts:

1. A straight ISA that will have a normal attachment node and a decoupling node for the Centaur.
2. The conical ISA that will have the fairing base. This will attach at the normal attachment node of the ISA.

For a single part: prioritize the fairing action in the part.cfg and use the right - click menu for the Centaur to decouple.

Edit: do you have plans for other launchers? Titan has not been touched by anyone (i think)...

Unfortunately for single parts, everything triggers at once when you stage it, unless you've disabled a function in the right-click menu.

I'm trying to picture how #2 would work. So you're saying use the same ISA, but have a fairing adapter that also snaps over it? It's possible. I'll look some more at the exploded views of the rockets and see if I get some further inspiration there too.

But yeah, Titan and Proton are two that I'm keeping in mind as possible things to add, once I get the "core" lifters assembled.

 

6 hours ago, Kartoffelkuchen said:

Also, Centaur has helium bottles and spheres for RCS propellant, the number of them increases as longer the missions are, on a side note.

 

I still have no idea how you can just work on soo many things and finish them so fast.

Yep, I'm thinking about adding some of those (part of my plan is to go back and add fuel pipes and other such details later, as time permits), but also probably make some hydrazine (monoprop in stock) spheres that can be radially attached there. I tried playing with the small monoprop spherical tank last night, and it looked pretty good mounted near the engines, except for its relatively smudgy appearance compared to these parts.

 

The speed with this pack is due to a few things. One is that I'm reusing assets. For some things I'm grabbing SpaceY parts, or just other things from this pack, and reworking them. A lot of the time spent modeling is just in laying out the UV maps, so when that's mostly already done and I just need to rearrange, it's a huge time saver. Another factor is that I've been spending an inordinate amount of time in my evenings on it (to my wife's dismay, lol ). And also, when I have a few free minutes at work, I'll remote into my home desktop and do a variety of tweaks. That's a good time to be writing up the configs and MM patches, etc. I can't keep this up all the time, but right now I'm being a little obsessive.

 

 

Edited January 20, 2016 by NecroBones

[Phineas Freak]

@NecroBonestake a look at the following Atlas V 500 Series diagram:

What i had in mind was to make the "Centaur Interstage Adapter" operate as a decoupler. It will have 3 attachment nodes, one on the bottom (for the CCB), one on the top (for the conical ISA) and one decoupler node close to the middle of the adapter (where Centaur will be attached). Then, make the "Centaur Conical Interstage Adapter" a hollow fairing base (Centaur will slip inside of it and it will attach on the decoupler node).

[NecroBones]

13 minutes ago, Phineas Freak said:

@NecroBonestake a look at the following Atlas V 500 Series diagram:

What i had in mind was to make the "Centaur Interstage Adapter" operate as a decoupler. It will have 3 attachment nodes, one on the bottom (for the CCB), one on the top (for the conical ISA) and one decoupler node close to the middle of the adapter (where Centaur will be attached). Then, make the "Centaur Conical Interstage Adapter" a hollow fairing base (Centaur will slip inside of it and it will attach on the decoupler node).

Yeah, that was one of the diagrams I was looking at. I see what you're saying. I may have to experiment a little, since having attachment nodes close together can cause all sorts of mayhem in the VAB.

 

-----

As an aside, I did add some spheres to the Centaur, and some ambient occlusion too.

[NecroBones]

Something I'm inclined to fudge is the SRM arrangements on the Atlas V, and just let people use normal symmetry modes. I'm not sure there's a clean way to recreate this:

 

 

(Luckily KSP doesn't have problems with attaching boosters on top of fuel feeds and avionics bays)

 

[Delta_8930]

1 hour ago, NecroBones said:

Something I'm inclined to fudge is the SRM arrangements on the Atlas V, and just let people use normal symmetry modes. I'm not sure there's a clean way to recreate this:

 

 

(Luckily KSP doesn't have problems with attaching boosters on top of fuel feeds and avionics bays)

 

The reason for that was because Atlas V wasn't originally designed for boosters, so LM just strapped the fuel lines and 1st stage avionics directly to the first stage tank. However, EELV requirements indicated that vehicles had to have boosters, and since the RD-180 has a large gimbal range, LM decided to strap on SRBs in an odd fashion. 

Kartoffelkuchen's Launchers Pack mod (KSP 1.0.4) had these SRB configurations for its Atlas V. I think you have to attach the booster decouplers to a "core alone" version and add boosters depending on how many you want. 

[NathanKell]

stack nodes, and the boosters having a stack node, would solve this, right? Just place the boosters without symmetry.

[NecroBones]

1 hour ago, NathanKell said:

stack nodes, and the boosters having a stack node, would solve this, right? Just place the boosters without symmetry.

That could work. The thing is, it's asymmetrical thrust for most of those configurations, which the Atlas V compensates for with thrust vectors I believe. It might be worth some experiments, but I want to avoid a situation where either more than one SRM config needs to be provided, or the player has to tune each SRM individually until the thing flies straight.

 

-------

On another note:

Atlas V common core booster tank is coming along nicely:

 

Edited January 21, 2016 by NecroBones

[Felbourn]

8 hours ago, NecroBones said:

Something I'm inclined to fudge is the SRM arrangements on the Atlas V, and just let people use normal symmetry modes. I'm not sure there's a clean way to recreate this:

(Luckily KSP doesn't have problems with attaching boosters on top of fuel feeds and avionics bays)

 

Atlas V solids are canted 3 degrees to help point the thrust toward the CoM more.

[NecroBones]

9 hours ago, Felbourn said:

Atlas V solids are canted 3 degrees to help point the thrust toward the CoM more.

Yeah, I figured there was a slant, but I hadn't looked for the amount yet. The Delta IV boosters tilt about 10 degrees. I may have to do some flights with some boosters manually placed asymmetrically and see if it's stable enough. But the boosters (and interstages) don't exist yet so it'll have to wait a little bit. I'll probably finish up the RD-180 first.

 

[Phineas Freak]

Also, these rockets are meant to be controlled by a closed - loop PID controller so the asymmetric thrust in reality is not a problem (the RD-180 compensates for it with it's 6 degrees of gimbal range). For KSP it is a tiny bit more difficult to control by hand but that's why we have MechJeb (or a good hand coordination)!

[NecroBones]

For the "stack" joints for SRBs, there needs to be decoupling involved too. So here's another choice to think about-- Add the decoupling to the tank, and then the SRBs can attach directly? Or make a specialized decoupler that only snaps into the pre-designed "radial stack" nodes? (the SRBs can't be the decouplers since they're SRBs, and staging will trigger everything in the same part).

 

Or just forget it and do normal radial attachment?

 

Any preference?

[Delta_8930]

Kartoffelkuchen created a special decoupler for decoupling the boosters. It contained joints at the top and the bottom for attachment. 

[Kartoffelkuchen]

Here's an image from MUOS-4 launch. You can see two struts on each SRB.

I made a bottom, roundish attachment joint, together with the two struts at the top, which are the decoupler. See here:

The two more struts at the bottom you can see on my images are not there on the "real decoupler" as it seems, it only uses the small joint on the bottom.

[NecroBones]

1 hour ago, Delta_8930 said:

Kartoffelkuchen created a special decoupler for decoupling the boosters. It contained joints at the top and the bottom for attachment. 

 

1 hour ago, Kartoffelkuchen said:

I made a bottom, roundish attachment joint, together with the two struts at the top, which are the decoupler. See here:

The two more struts at the bottom you can see on my images are not there on the "real decoupler" as it seems, it only uses the small joint on the bottom.

 

Cool, I may need to take a look at what you did.

 

[NecroBones]

This is starting to look like a booster. Yay

 

[NecroBones]

On 1/20/2016 at 2:54 AM, Phineas Freak said:

@NecroBones for the Atlas V 500 interstage, you can break it down into two parts:

1. A straight ISA that will have a normal attachment node and a decoupling node for the Centaur.
2. The conical ISA that will have the fairing base. This will attach at the normal attachment node of the ISA.

 

I thought some more about this idea, and from a staging perspective, I can see how to make it work well. But the unknown that I have is how it would affect aerodynamic shielding in stock aero. Since the fairing base and centaur would both be attached to the interstage, and not each other, I don't know if that has any impact on figuring out what's "inside" the fairing. It could be that it makes no difference at all, since I know they do a scan based on radius from the fairing center, and whether part centroids fall within the fairing colliders. But I'm not sure if they do further culling of the list based on how things are attached. Just something to consider.

 

It could still be made pretty simple by making the centaur tank act as the decoupler, and the 500 interstage can then just be a single-piece fairing base.

 

5 hours ago, Delta_8930 said:

Kartoffelkuchen created a special decoupler for decoupling the boosters. It contained joints at the top and the bottom for attachment. 

 

4 hours ago, Kartoffelkuchen said:

I made a bottom, roundish attachment joint, together with the two struts at the top, which are the decoupler. See here:

The two more struts at the bottom you can see on my images are not there on the "real decoupler" as it seems, it only uses the small joint on the bottom.

 

OK I see what you did. It is just a traditional radial decoupler, just one that is really tall and is invisible in the center. Technically the decoupler attaches to the tank at just the bottom point, and the booster attaches to the decoupler just at the center point.

[Kartoffelkuchen]

Yes of course it is, how else would you do it?

[NecroBones]

2 minutes ago, Kartoffelkuchen said:

Yes of course it is, how else would you do it?

I wasn't sure since you guys brought it up after we were talking about the idea of doing it with pre-placed stack nodes.   I'll probably do something more like what you did, since it gives the player the most flexibility. BTW, awesome job on the modeling. It's really beautiful work you did there.

[Kartoffelkuchen]

Ah ok then!

Aw thanks man! Great to hear that from you! :]

 

[NecroBones]

So I'm slightly confused. I finally have an Atlas V standing up, in the 402 configuration. It looks too tall. I've been using the lengths mostly from the image below, but also lengths and diameters from other sources, that mostly seem to match up. But the "Common Centaur" I think is a little longer than earlier versions, but both stages look too long to me. I also took into account that I had to subtract out the length of the engine from the length of the first stage booster from some of the stats I found. I may have to shorten things a little, but I'm not sure where the error came from.

 

Interstage lengths from here: http://www.spacelaunchreport.com/atlas5.html (and the image below)

Other dimensions from: wikipedia, and the Atlas V user's guide, and  http://www.ulalaunch.com/products_atlasv.asp and http://spaceflight101.com/spacerockets/atlas-v-401/

For instance, according to that last link, the CCB (first stage) is 32.46m in length. After subtracting roughly 3.5m for the engine, I made mine 29m in length in the tank. I wonder now if they're also including the interstage? Not according to the diagram below. That also shows 32.46m from the base of the engine, to the bottom of the interstage.

 

So maybe the error is entirely in making the Centaur too long? They also show that as 12.68m. I made it 9.6 from the top rim (not the domed part) down to the engine mount. Including the dome, it's about 10.3, and adding the engine only brings it to about 11.5, but it too looks stretched.

 

Any ideas?

 

 

 

[NecroBones]

More on the size problems... A comparison of @Kartoffelkuchen's Atlas V next to mine. Aligned them such that the top of the white engine housings line up. Ignore the fairings, I'm looking at the first and second stages. I definitely have the wrong lengths, but I'm not sure why the various numbers I've been finding have lead me astray.

 

EDIT: I do see one thing that's out of place with regard to the diagram in the previous post. It shows a length of the outer casing of the Centaur as 8.71, and mine is measuring 10.6. I should start there.

 

Edited January 22, 2016 by NecroBones