SSU Development thread (4.0 to 5.0) [DEVELOPMENT HALTED DUE TIME REQUIREMENTS!]

[GLS]

No, just the body flap. Was about a five-minute job really. I've attached it to this post just in case you want to look at it. It's in a better position now (further aft) as the round section should be partially visible.

Aside from the gaps on the sides, the diameter of the round part is too small, the radius should be 0.26924m (center at Zo 287, bottom at Zo 276.4). Also, from photos and diagrams, the body flap is flat until the round part, i.e., it doesn't have a "step".
I have this almost done.

 

[DaveS]

Aside from the gaps on the sides, the diameter of the round part is too small, the radius should be 0.26924m (center at Zo 287, bottom at Zo 276.4). Also, from photos and diagrams, the body flap is flat until the round part, i.e., it doesn't have a "step".
I have this almost done.

What do you mean by flat? Are you talking when seen from top/bottom that it isn't supposed to have a straight section before the tapered section?

 

[GLS]

What do you mean by flat? Are you talking when seen from top/bottom that it isn't supposed to have a straight section before the tapered section?

The sides have that "slice", the top and bottom is flat/constant until the circular section.

 

[DaveS]

The sides have that "slice", the top and bottom is flat/constant until the circular section.

That schematic isn't quite right when you compare it to an actual photo of an body flap, of which I have attached to this post. The red box outlines the round section, while the green box outlines the main structure. Do note the straight section ahead of the tapered section of the main structure.

 

[GLS]

That schematic isn't quite right when you compare it to an actual photo of an body flap, of which I have attached to this post. The red box outlines the round section, while the green box outlines the main structure. Do note the straight section ahead of the tapered section of the main structure.

The red box is the round already. Our body flap had was flat starting in the kink in the green line.
The Atlantis photo seems to indicate the top is different from the bottom....

 

[DaveS]

Try the attached new body flap. The radius is now per your specs as well as the positions. I have included a modified hinge as well.

 

[GLS]

I think I figured out why the OMEs are hitting the RCS pods: I corrected the top-aft end of the aft compartment and now there is a gap to the OMS pods (and an even bigger one to the tail :facepalm. That means that (at least) the aft end of the OMS pods is not well positioned, and as we know where the OMEs should be (so they won't move now),the RCS pods will (hopefully) move away in the correction.

The key question now is: what is the position of the top end of the sides of the aft compartment? (the corner just above and aft of the umbilicals) This determine the position of the aft end of the OMS pods.

 

[DaveS]

I think I figured out why the OMEs are hitting the RCS pods: I corrected the top-aft end of the aft compartment and now there is a gap to the OMS pods (and an even bigger one to the tail :facepalm. That means that (at least) the aft end of the OMS pods is not well positioned, and as we know where the OMEs should be (so they won't move now),the RCS pods will (hopefully) move away in the correction.

The key question now is: what is the position of the top end of the sides of the aft compartment? (the corner just above and aft of the umbilicals) This determine the position of the aft end of the OMS pods.

Are you talking about about where shoulders of the aft engine compartment meet the midbody? That's a straight line except in the Y-axis where it flares out (aft end is wider than the forward end). The top end is at Zo518.5 The bottom straight line is at Zo417.7.

 

[GLS]

Are you talking about about where shoulders of the aft engine compartment meet the midbody? That's a straight line except in the Y-axis where it flares out (aft end is wider than the forward end). The top end is at Zo518.5 The bottom straight line is at Zo417.7.

The Zo417.7 seems to be what I need, and the point is pretty much there... I have to see how things shape up at the fwd end, as in the end the OMS pod probably attaches to a flat surface.

The Zo518.5 is near the top aft end of the aft compartment, but in a previous post you said that it was Zo517...

Another point of interest is the center of the aft face of the aft compartment: currently the vertex is under the center SSME, but it should be just below it.

 

[DaveS]

The Zo417.7 seems to be what I need, and the point is pretty much there... I have to see how things shape up at the fwd end, as in the end the OMS pod probably attaches to a flat surface.

They do. The shoulders of the aft engine compartment are completely flat. I've attached a photo of Endeavour's ROMS pod on the OMS pod transporter showing how it is attached in a horizontal position. I've also included a photo the left shoulder of Endeavour's aft engine compartment without the OMS pod.

The Zo518.5 is near the top aft end of the aft compartment, but in a previous post you said that it was Zo517...

That was estimated based on the schematics in Vol. III of JSC-11174. The Zo517 number came from Vol. II of Jenkin's shuttle book-set. Considering Jenkins used to work in the shuttle program, I'd trust the Zo517 number over my schematic estimate.

 

[DaveS]

GLS: Are you working on the radiator panels right now? I thought I'd fix up a things with them. I'm just about done with the first panels (panel#1 on both sides).

 

[GLS]

GLS: Are you working on the radiator panels right now? I thought I'd fix up a things with them. I'm just about done with the first panels (panel#1 on both sides).

It's on the list, but not at the top, so you are go for it. Despite the hectic week, yesterday I flattened the fwd windows (much better reflections now), and next on the list are the overhead windows.
About the radiators, the flat surfaces should match the edges, such that each "kink" is both in the flat surface and the edges. Otherwise we are wasting resources and things don't match. :shrug:

Also, PLEASE, once you're done, open the "original" mesh in a text editor and replace just the group(s) you edited, so that is the only change in the mesh file. That way it's much easier to isolate changes, avoid editing mistakes in other parts, and no code recompile is needed.

 

[DaveS]

It's on the list, but not at the top, so you are go for it. Despite the hectic week, yesterday I flattened the fwd windows (much better reflections now), and next on the list are the overhead windows.
About the radiators, the flat surfaces should match the edges, such that each "kink" is both in the flat surface and the edges. Otherwise we are wasting resources and things don't match. :shrug:

Yes, I noticed this when correcting the texture mapping on panel#1. I've fixed this on those and now that I know that they're free to fix, I'll move along with the remaining 7 panels.

Also, PLEASE, once you're done, open the "original" mesh in a text editor and replace just the group(s) you edited, so that is the only change in the mesh file. That way it's much easier to isolate changes, avoid editing mistakes in other parts, and no code recompile is needed.

I'll do this once I'm done.

 

[GLS]

Yes, I noticed this when correcting the texture mapping on panel#1. I've fixed this on those and now that I know that they're free to fix, I'll move along with the remaining 7 panels.

Don't worry about the mapping for now, first we have to get all the vertices in the right places. Mapping is the last item on the list.

 

[DaveS]

Don't worry about the mapping for now, first we have to get all the vertices in the right places. Mapping is the last item on the list.

The corrected mapping is on the panel itself, not the semi-cylindrical edges, these are what needs to be resized and that doesn't affect their mappings.

 

[GLS]

The corrected mapping is on the panel itself, not the semi-cylindrical edges, these are what needs to be resized and that doesn't affect their mappings.

Even the panel (the big surfaces) need work.

 

[DaveS]

Even the panel (the big surfaces) need work.

In what way?

 

[GLS]

In what way?

As it is visible, the vertices are in groups along the radiator curve, and in the "big surface" there are large flat areas, and then many small areas. This makes it look "steppy" and not smooth. Ideally, areas with more curvature should have more vertices, but not like the current grouping which I'm sure is wasteful.

 

[DaveS]

Spent some time and I came up with this alternate design with less vertices and only kept the groups where they were necessary. Is it acceptable?

 

[GLS]

Spent some time and I came up with this alternate design with less vertices and only kept the groups where they were necessary. Is it acceptable?

Looks much smoother. And if it's cheaper, even better. :thumbup: