Centaur G/G Prime High Energy Upper Stage

[DaveS]

Hi there, I love the work you guys do its really beyond me and my machine but do love it,
what I'd like to ask is I have managed to get the old Centaur prime from your last release SSU 2 to work with the shuttle fleet and would like to release it to the community, I would make it clear that the work is yours and would not pass it off as my own.
I of course couldn't get the pipes in the CISS to flex but I have it there is a separation valve in there when it rotates maybe it might help you in your work to see it.
thanks for all your work and would be pleased to get your response
David

I think we had it set up correctly. Are you using the included Centaur/CISS files?

 

[GLS]

I'm doing the adapter stuff now, and this question came up: we need 1 offset for the adapter, and then another for the spacecraft, right? But, instead of having 2 offsets, could we *force* the users to have the center of their adapter mesh exactly in between the plane where the spacecraft meets it and the plane where it meets the Centaur? Thus allowing for just 1 offset in the scenario file, adapter offset, and we just multiply by 2 to get the spacecraft offset. I used all my paint skills :lol: and made this diagram to illustrate this.

 

[DaveS]

I'm doing the adapter stuff now, and this question came up: we need 1 offset for the adapter, and then another for the spacecraft, right? But, instead of having 2 offsets, could we *force* the users to have the center of their adapter mesh exactly in between the plane where the spacecraft meets it and the plane where it meets the Centaur? Thus allowing for just 1 offset in the scenario file, adapter offset, and we just multiply by 2 to get the spacecraft offset. I used all my paint skills :lol: and made this diagram to illustrate this.

I think that "forcing" the users to put the adapter at the interface plane is the way to go.

 

[GLS]

I think that "forcing" the users to put the adapter at the interface plane is the way to go.

I'm not sure I'm following you... are you saying the center of the adapter should be at its the bottom plane, and then the only offset required is the spacecraft offset? Or the mesh center should be at its top plane and then we get a adapter offset?

 

[GLS]

Something like this?

 

[DaveS]

Something like this?

The offset would be single and correspond to where the adapter meets the payload.

 

[GLS]

The offset would be single and correspond to where the adapter meets the payload.

OK, makes sense. Coding this way then. :thumbup:

 

[Loru]

This plumbing gives me a headache.

 

[DaveS]

This plumbing gives me a headache.

Yeah, those are a really PIA.

 

[orbitingpluto]

First time commenting, so I kinda feel I'm butting in, but I think the spacecraft deserves it's own offset, without any odd ties to the adapter. I don't have a suggestion in mind, but what I worry about is having a clunky system that works well on the developer side but falls short on user friendliness. If the payload is too long or too short to fit in adaptor*2, or if moving the attachment also moves the adapter around, one thing I see happening is having to open up the payload's .cfg and edit it's attachment point around so it fits SSU- meaning I'll having to edit two files to add a payload to Centaur, rather than fiddle with only one.

 

[DaveS]

First time commenting, so I kinda feel I'm butting in, but I think the spacecraft deserves it's own offset, without any odd ties to the adapter. I don't have a suggestion in mind, but what I worry about is having a clunky system that works well on the developer side but falls short on user friendliness. If the payload is too long or too short to fit in adaptor*2, or if moving the attachment also moves the adapter around, one thing I see happening is having to open up the payload's .cfg and edit it's attachment point around so it fits SSU- meaning I'll having to edit two files to add a payload to Centaur, rather than fiddle with only one.

I think you have misunderstood the adapter. The adapter is payload specific. It isn't tied to the Centaur, rather it's tied to the spacecraft.

Every payload mates to its launch vehicle through a structure called a "Payload Attachment Fitting" or PAF. It's usually conical in shape and at one end has fittings that match the ones on the LV and on the opposite end has fittings that match the ones on the spacecraft.

Here's a set of photos that shows various PAFs circled in red. What they do have in common is that all were spacecrafts that used the IUS. So while the upper stage was the same, the spacecrafts weren't so they had their own "IUS/payload adapters".

Galileo:

TDRS:

Ulysses:

 

[GLS]

We were talking about the offset to the attachment on the spacecraft not its cg. The "adaptor*2" thing was just a way to get the attachment offset for the spacecraft, but the suggestion DaveS gave is much better.
So, to use the Centaur, a spacecraft must have an attachment point at the place where it attaches the adapter, i.e, at the bottom (and its cg can be wherever its creator wants it to be), and if it uses an adapter we must know, via scenario file, the name of the mesh and basically the height of that adapter (payload offset).
The adapter mesh must have its center at the top end, that's our only request. Payloads wanted!

 

[Urwumpe]

This plumbing gives me a headache.

Still harmless...

And that is just a SSME... you don't want to see what the Russians do to harmless turbomachinery.

 

[orbitingpluto]

I understand what's being proposed better, but it still sounds clunky and user unfriendly. Custom adapter meshes and editing more than one file to get everything to sit pretty in the payload bay doesn't sound easy to use.

My preference would to be able to set the offsets myself, and possibly the ROT and DIR values, in just the scenario file for at least the adapter. Since DaveS's proposed method depends on having a SSU-adapted adapter mesh, I worry that'll restrict people like me who don't have any inclination to learn to mesh, so being able to scenario edit non-SSU built adapters onto Centaur is important to me.

Being able to set the spacecraft's attachment point in the scenario file would be nice, but if it's hassle to implement I think I can deal with setting up the spacecraft's .cfg to fit SSU.

 

[DaveS]

I understand what's being proposed better, but it still sounds clunky and user unfriendly. Custom adapter meshes and editing more than one file to get everything to sit pretty in the payload bay doesn't sound easy to use.

My preference would to be able to set the offsets myself, and possibly the ROT and DIR values, in just the scenario file for at least the adapter. Since DaveS's proposed method depends on having a SSU-adapted adapter mesh, I worry that'll restrict people like me who don't have any inclination to learn to mesh, so being able to scenario edit non-SSU built adapters onto Centaur is important to me.

Being able to set the spacecraft's attachment point in the scenario file would be nice, but if it's hassle to implement I think I can deal with setting up the spacecraft's .cfg to fit SSU.

The PAF mesh/offset would be in the scenario. The PAF stays with the upper stage. The offset is for the Centaur module to know where to set the attachment point to the spacecraft.

The image below shows the outline of a hypothetical PAF and where it goes on the Centaur. The white conical section is the Centaur Equipment Module (EM) where all of the avionics boxes lives as well as the structural interfaces which secure the forward end to the orbiter. The blue line is where the offset will be applied while the green line is origin (0,0,0) of the PAF mesh. When the jettison command is sent, only the spacecraft will be jettisoned while the PAF stays with the Centaur.

 

[GLS]

The blue line is where the offset will be applied while the green line is origin (0,0,0) of the PAF mesh.

Wasn't the adapter mesh center on top? (blue line)

 

[DaveS]

Wasn't the adapter mesh center on top? (blue line)

Could you explain this further? I don't quite understand "center on top".

 

[GLS]

The center of the adapter mesh, wasn't it decided to be at it's top plane? You now say it's at the bottom plane...

 

[DaveS]

The center of the adapter mesh, wasn't it decided to be at it's top plane? You now say it's at the bottom plane...

Now I understand. Yes now I remember. That's correct.

 

[DaveS]

I looked at the CISS source code and noticed the animations for the actual propellant ducts is commented out. What is the reason why they're commented out?