[WIP/Planning] SDHI AeroFairings - incrementally tweakable clamshell payload shrouds

[sumghai]

Payload shrouds for rockets have always bothered me, long before the controversy surrounding the stock potato-chip fairings in KSP 1.0.

Currently, one has the following options for protecting their payload during ascent:

	Pros	Cons
Stock Procedural Fairings	- Allows manual drawing of shroud profile around payload - Low part count in VAB/SPH (choose desired base diameter) - When editing payload, shroud segments automatically move out of the way (convenience)	- Potato-chip style fairing jettision is visually unappealing - Shrouds do not have mass - Allows nonsensical shroud designs (e.g. very tall or fat payloads on top of a tiny lifter rocket)
e-dog's Procedural Fairings	- Low part count in VAB/SPH (tweakable base diameter) - Automatically conforms to payload - Clamshell fairing jettision - Supports interstages	- Allows nonsensical shroud designs (e.g. very tall or fat payloads on top of a tiny lifter rocket)
KW Rocketry Fairings (or equivalent)	- Built-in decoupler - Clamshell fairing jettision - Shroud pieces have mass / cost - Individual segments limit shroud to sensible designs	- Non-intuitive assembly procedures - High part count as shrouds are built up from multiple discrete parts - Separate fairing bases for straight and boattailed shrouds - When editing payload, fairings must be manually moved aside, breaking staging
Zero-Point Inline Fairings (uses auto-shroud feature from stock engine PartModule)	- Easy support for interstages - Fixed fairing sizes limit shroud to sensible designs	- Part list bloat from numerous fairing size/shape variants - Lack of true clamshell fairing behaviour (nose code comes off separately from rest of fairing

Looking at the comparison above, my biggest personal annoyance was that most fairing systems allow the user to build whimsical and ungainly payloads, and then slap a set of fairings around it as an afterthought. In real life, fairings are standardized, mass-produced components for ease of manufacturing and to keep costs low, while payloads are, correspondingly, more sensible in size and shape (giant space stations are built by docking sensibly-sized modules in orbit, not launched in one go).

KW Rocketry Fairings is heading in the right direction with standardized fairing components, but its high part count, part list bloat and non-intuitive assembly method can be discouraging. Also, the KW fairings still technically allow extremely long payloads.

As such, my intention is to create an alternative payload fairing system that combines the best features of the current options on the market, while also imparting some sensible restrictions.

Sum Dum Heavy Industries AeroFairings

Features

- Fairing bases available in 1.25, 2.5 and 3.75m diameters
- Semi-procedural two-way shrouds with tweakable options:
    - Straight or boattail bottom segment
    - One, two or three mid-segments (four would be too tall)
    - Conical or ogive nose cone
    - Three material choices: stockalike, clean, Copernicus MTV-style heat shield tiles
- Shrouds move out of the way when editing payload
- Shrouds have mass and cost that increases with size
- Shrouds are persistent debris after jettison.
- Lower overall cost due to standardized components / mass production
- Standalone add-on with NO dependencies

Not Planned

- Three or four-way fairings (not common on contemporary 2000's and 2010's rockets)

- Interstages (most contemporary payloads are launched at the very top of the rocket)

Implementation Details / Plans

Making the models is the easy part, as all that's needed are:

- One fairing base

- One straight bottom segment

- One boattail bottom segment (same height as straight bottom segment; upper diameter is 125% 140% of base diameter???)

- One standard mid-segment (height = diameter)

- One conical nose segment (height = diameter)

- One ogive nose segment (height = diameter)

A custom plugin will take these assets, scale/duplicate them appropriately and build them into one-piece clamshell fairing halves. The plugin will also natively handle procedural cost and mass, as well as the switching of the fairing material and the VAB/SPH ghosting animation.

Questions

- Any seasoned plugin authors interested in helping out?

- I'm a bit concerned about texture scaling, especially for the Copernicus MTV aeroshell-style heat shield tiling. I would prefer that (most of) the tiles have constant size across all fairing sizes, to fit with the standardized components / mass production ethos - but at the same time, I want to keep the number/size of textures at a minimum. Does this matter to you guys, or is it okay if the larger fairings end up having bigger heat shield tiles overall?

[_Augustus_]

Could you make in-between-sizes fairing sizes?

I.e:

1.875m

3.125m

4.325m

?

[Sampa]

seems interesting! I might help you test these when they are ready...if you need me to, that is!

[sumghai]

Could you make in-between-sizes fairing sizes?

If you're referring to the base diameters, then no, I have no plans to support non-standard rocket fuselage diameters.

seems interesting! I might help you test these when they are ready...if you need me to, that is!

My policy on beta testing still applies - I'll put my WIPs on GitHub so that anyone can try it out.

Edited April 28, 2015 by sumghai
Whoops, missed Sampa's reply >.<

[Mecripp]

Can't wait to see what you come up with

EDIT- O and you did forget one and sorry, I'll thing of the name in a bit.

EDIT- Here it is Zero Point Inline Fairings http://forum.kerbalspaceprogram.com/threads/94427

Edited April 29, 2015 by Mecripp2

[sumghai]

EDIT- Here it is Zero Point Inline Fairings http://forum.kerbalspaceprogram.com/threads/94427

Dual-manifesting payloads isn't planned right now, but it's something I'd like to look into in the distant future.

EDIT: I think I figured out what you were trying to say.

Edited May 5, 2015 by sumghai

[Akira_R]

As far as the texture issue I would like to see the tiles stay a reasonable size, perhaps talk with bac9 about how he got his procedural wings system to work, if you haven't used looked at it it allows you to create a procedural part but it doesn't stretch the texture at all, and i keeps ram usage pretty small. Perhaps you can use some of his code as well, of course i am no programmer so no idea if that is feasible or not.

[sumghai]

As far as the texture issue I would like to see the tiles stay a reasonable size, perhaps talk with bac9 about how he got his procedural wings system to work, if you haven't used looked at it it allows you to create a procedural part but it doesn't stretch the texture at all, and i keeps ram usage pretty small. Perhaps you can use some of his code as well, of course i am no programmer so no idea if that is feasible or not.

I've had a look at his source code, and I think the way it handles textures is what I should be aiming for, although I'm hoping that's not dependent on KSPAPIExtensions.

[Bomoo]

Woo new thread!

So question: will this fairing generation system have an option to replace the nosecone segment with an LES (i.e. generate a noseless fairing with a 1.25m attachment node like your Mk1-2 pod cover)? I mean, strictly speaking, when pairing this with your kerbalized Orion parts kit, an LES on this fairing system isn't really necessary as the Mk1-2 upgrade kit covers all your crew launch needs. But in case you want to build something fancy like, say, a kerbalized Soyuz or some other crazy custom crew ferry using this fairing system.

[sumghai]

So question: will this fairing generation system have an option to replace the nosecone segment with an LES (i.e. generate a noseless fairing with a 1.25m attachment node like your Mk1-2 pod cover)? I mean, strictly speaking, when pairing this with your kerbalized Orion parts kit, an LES on this fairing system isn't really necessary as the Mk1-2 upgrade kit covers all your crew launch needs. But in case you want to build something fancy like, say, a kerbalized Soyuz or some other crazy custom crew ferry using this fairing system.

This is an interesting idea, but I doubt it'll be in the early releases. Besides, I don't understand enough about the Soyuz LES at this stage.

[Crzyrndm]

although I'm hoping that's not dependent on KSPAPIExtensions.

It's not, everything is handled internally (not sure what you would think it was using KAE for?)

Edited April 29, 2015 by Crzyrndm

[sumghai]

It's not, everything is handled internally (not sure what you would think it was using KAE for?)

Ah, I see.

I simply saw KAE cropping up in numerous places, but had no idea what it was used for (other than helping plugin authors do special things )

[Crzyrndm]

Mainly add things to the tweakables (such as sliders with increment buttons) from what I've seen. Since PWings uses it's own GUI window it doesn't need any of that

[Mecripp]

AIES has a good Fairings setup but there could be some just alittle longer.

Edited April 29, 2015 by Mecripp2

[Konnor]

This idea looks like an optimal combination of convenience and challenge. A couple of questions.

Will you add a decoupler module, as in KW Rockets fairings? It is really convenient I think, and you listed it in Pros section.

Do you consider making also a 5m fairing base? I'm aware you've said no to non-standard sizes, but _Augustus_ was asking about intermediate sizes, and 5m would be the next full stop after 3.75. Besides, KW has them, and 5m makes sense as a kerbal-sized SLS core stage which is about 8m in real life. And while overpowered for stock-sized Kerbin, 5m lifters are viable for 6.4x scaled system or RSS.

[plausse]

but...

http://www.ata-e.com/asymmetric-payload-fairing

[Mecripp]

This is kind of funny people asking about size when you can rescale them to your needs.

[sumghai]

Will you add a decoupler module, as in KW Rockets fairings? It is really convenient I think, and you listed it in Pros section.

It's a neat idea that I considered, but there's a bit of a problem.

The fairing bases in KW Rocketry have stack decouplers, but that's only because the fairing halves themselves (being separate parts) have their own built-in radial decouplers, allowing them to be staged separately.

The staging action for the SDHI AeroFaring bases is reserved for the fairing jettison, and so adding a stack decoupler PartModule would cause the payload to be released at the same time the fairings come off (I don't think one part can have two staging icons). There are two ways to work around this:

- Design the AeroFairing so that with one staging action, the fairing halves are jettisoned, and after a short (tweakable?) delay, automatically decouple the payload. Extremely convenient in most cases, but there may be situations where the user wants to manually determine when to decouple the payload (or maybe the user is dual-manifesting and wants to decouple the upper payload first).

- Have the user just attach a separate decoupler part. Not as convenient, but covers all possible use cases.

Do you consider making also a 5m fairing base? I'm aware you've said no to non-standard sizes, but _Augustus_ was asking about intermediate sizes, and 5m would be the next full stop after 3.75. Besides, KW has them, and 5m makes sense as a kerbal-sized SLS core stage which is about 8m in real life. And while overpowered for stock-sized Kerbin, 5m lifters are viable for 6.4x scaled system or RSS.

That's a possibility, but right now, I'd like to focus on the more common stock 1.25/2.5/3.75 families.

but...

http://www.ata-e.com/asymmetric-payload-fairing

Yes, I am aware that asymmetric payload fairings exist in real life - however, because they are one-off bespoke solutions, the development / manufacturing / certification costs are significantly greater than mass-produced cylindrical fairings with standardized proportions.

The point of SDHI AeroFairings is to have sensible, turnkey designs at affordable prices to end users.

[Konnor]

rescale them

Might not work in presence of custom plugin that determines the actual size.

The staging action for the SDHI AeroFaring bases is reserved for the fairing jettison

I see. Using separate decoupler is better then, since delayed staging limits possibilities severely; that stage with a fairing base could be needed to stay attached for quite a long time (as in, during interplanetary transfer).

[sumghai]

This is kind of funny people asking about size when you can rescale them to your needs.

Might not work in presence of custom plugin that determines the actual size.

The fairing bases will be available in three different diameters under the VAB/SPH parts list. There is only one model file, but the CFG files will use the bog-standard MODEL{} scale factor to make the three variants.

The custom plugin is for tweaking the actual fairing shrouds, which are generated from the fairing bases.

I see. Using separate decoupler is better then, since delayed staging limits possibilities severely; that stage with a fairing base could be needed to stay attached for quite a long time (as in, during interplanetary transfer).

Indeed - and sometimes, there are situations where you don't want to have decouplers at all - e-dog suggested that users could even stick a docking port on his Procedural Fairing base to make a one-time shielded docking port.

[Stealthyboy]

Would your system be able to jettison only half of the fairing, letting the other half stay attached for use as a long, horizontally aligned heatshield similar to what was done in this video: https://youtu.be/Tp6yj2k0Fpc?t=5m31s

[sumghai]

Would your system be able to jettison only half of the fairing, letting the other half stay attached for use as a long, horizontally aligned heatshield similar to what was done in this video: https://youtu.be/Tp6yj2k0Fpc?t=5m31s

I originally had something like that in mind as a possible use case, but I've now decided against supporting that configuration, since it would detract from the simplicity of jettisoning fairings with a single staging action.

I would assume that one would just need to keep both halves of the fairing attached to the lander until the end of atmospheric re-entry, and then eject both halves as soon as neither are no longer needed.

[ZobrAA]

Could you make in-between-sizes fairing sizes?

If you're referring to the base diameters, then no, I have no plans to support non-standard rocket fuselage diameters.

Actually KW Fairings have 1.25, 2.5, 3.75 regular AND extended variants... Stock diameters very often are a little bit narrower than just needed...

So more options of wideness are very appreciated

[sumghai]

Actually KW Fairings have 1.25, 2.5, 3.75 regular AND extended variants... Stock diameters very often are a little bit narrower than just needed...

So more options of wideness are very appreciated

If you had read my OP, you'll see that the boattail variants will have a base diameter of 1.25/2.5/3.75m, but also a max diameter of ~125%.

(SDHI Boattail AeroFairings = KW Extended Fairings)

[Boamere]

Ermahgerd Sumghai is at it again! Awesome! I'll be watching this