SSU Launch Complex 39 development

[Urwumpe]

For the SSMEs: do you mean that you can't see the SSME exhaust textures anymore? Weired. I can see them just fine, but then again, I'm using Mcwgogs's updated SSME exhaust texture.

No, worse: No thrust. Thruster level stays locked to 0.0.

 

[DaveS]

Now that is a weired problem! I just did a successful launch, no issues. Just need the LCC vessel to automatically trigger ME start at 6.6 seconds in a staggered fashion, each 0.3 seconds apart.


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Another good thing to have would be actual GOX vapours from the GVA.


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Oh and the new MLP has been checked in. Currently figuring out the best way to redo the main FSS structure with a lower triangle-count.

 

[Urwumpe]

Oh and the new MLP has been checked in. Currently figuring out the best way to redo the main FSS structure with a lower triangle-count.

A bit less would be good. If you can't do it with much lower, maybe we can squeeze some FPS out by switching between lower quality and high quality meshes depending on camera position.

Personally, I can live with only the access arm level having some good details.

The SSME throttle problems seem to only happen when the Shuttle is attached to the MLP.

 

[SiameseCat]

I was testing the autopilot yesterday and the SSMEs were working fine (and the shuttle was attached to the MLP). I'll put in the SSME start code.


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Urwumpe: Are there any existing functions to start a SSME or do I need to put one in? For the moment, I'm assuming this would only have to set the thruster level of the SSME to 1.0

 

[Urwumpe]

Urwumpe: Are there any existing functions to start a SSME or do I need to put one in? For the moment, I'm assuming this would only have to set the thruster level of the SSME to 1.0

I did not yet change this one, as long as the SSME code of GLS was still untested. Wanted to keep the chance to disable the new code if it does not yet work.

Also, it works when the Shuttle is not attached to the pad.

 

[tblaxland]

Now that is a weired problem! I just did a successful launch, no issues. Just need the LCC vessel to automatically trigger ME start at 6.6 seconds in a staggered fashion, each 0.3 seconds apart.

You know, I might not have noticed it if you didn't mention it, especially with my frame rates :lol:. I wasn't aware of this delay previously so I did some Googling. This site (granted, not official NASA source) nominates a delay of 0.12s:
http://www.globalsecurity.org/space/library/report/1988/stsover-launch.html

 

[Donamy]

DaveS, I can take a look at the FSS and see if I can reduce the poly's some.

 

[DaveS]

DaveS, I can take a look at the FSS and see if I can reduce the poly's some.

That will be kinda hard since I deleted it completely. But here's a breakdown of the various components:

-GOX vent arm truss: 1488
-GOX vent hood: 1580
-GOX vent arm access stairs: 224
-GOX vent hood access platform: 2090
-Orbiter Access Arm: 1060
-White Room: 571
-FSS OWP: 400
-FSS OWP south side supports: 684
-FSS/RSS Hinge Line bridge: 3210
-MAPU: 6008
-Intertank Access Arm: 6553
-Lightning mast+support: 276

 

[Donamy]

Why did you do that ?

 

[DaveS]

Why did you do that ?

Mostly because it had a few flaws and I wanted to redo it from the ground up better this time.

 

[Donamy]

OK!
BTW, I reduced the RSS from 19000 to about 13000 vertices.

 

[DaveS]

OK!
BTW, I reduced the RSS from 19000 to about 13000 vertices.

Great! But then again the RSS is far from done.


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I have now started on redoing the main FSS structure. For each side of the levels of the FSS, the best I can do is 60 triangles. But I believe this is contrast against the 500+(best approximate guess) triangles for each side of the old FSS.

I hope this will be of some relief.

 

[SiameseCat]

The T0 umbilical animations are on sourceforge. I haven't animated the covers yet.
DaveS: Does the retract speed look right to you?

 

[DaveS]

The T0 umbilical animations are on sourceforge. I haven't animated the covers yet.
DaveS: Does the retract speed look right to you?

Too slow. They need to be much faster. They retract very fast, my research tells me 1.1 seconds for full retraction.

 

[DaveS]

Great! But then again the RSS is far from done.


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I have now started on redoing the main FSS structure. For each side of the levels of the FSS, the best I can do is 60 triangles. But I believe this is contrast against the 500+(best approximate guess) triangles for each side of the old FSS.

I hope this will be of some relief.

Managed to find a old back-up of the old FSS and total trianglecount was 9992! Trianglecount per side was 100.

The new FSS is done with a total trianglecount of 3072, a grand saving of 6920 triangles! Not bad!

 

[DaveS]

Still working on the FSS. More specifically, the MAPU structure and Intertank Access Arm. By redoing both structures, I expect to cut alot of unnecessary triangles. ¨

Right now the MAPU structure is almost done and it only has 416(!) triangles compared to 6008 triangles before. All done I expect it be no more than 1500 triangles. Same deal when it comes to the Intertank Access Arm.


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MAPU structure pretty much done except for some minor elements and handrails and so far the trianglecount is 828, well within my expectations.

 

[SiameseCat]

TSM covers are animated now. I've also sped up the animation.

 

[DaveS]

TSM covers are animated now. I've also sped up the animation.

Looks good.


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How is it coming with GOX Vent Arm venting and FSS illumination? And speaking of FSS illumination, you should add some "beacons" that can act as the pad lights.

There are three types of lights at the pads.

The most basic type and most often seen is the so called "pad lights". You can see them as the red lights on the FSS, RSS and MLP here: http://science.ksc.nasa.gov/shuttle/countdown/video/chan3large.jpg

Then we have the second type, the pad stadium lights. These are used to illuminate the pad during critical pad operations. They usually illuminates the pad with a blue/greenish hue.

Then we have the third and most strongest lights, the pad xenon lights. These are the lights used to really light up the pad and stack and has a white hue to it. These lights are trailer-mounted and placed in pairs of two to the north, northeast, east, southwest and south of the pad, inside the pad perimeter.

They usually activate the xenons after RSS rotation to PARK for launch. These lights are what we currently simulate with the pad illumination.

Here's a photo from STS-115 in September 2006 that shows the east xenon light trailers: http://www-pao.ksc.nasa.gov/kscpao/images/large/06pd2065.jpg

 

[Urwumpe]

How is it coming with GOX Vent Arm venting and FSS illumination? And speaking of FSS illumination, you should add some "beacons" that can act as the pad lights.

I think I can put some quick GOX venting between, though maybe not realistic.

About the launch sequence control: I have a theory, what are your thoughts about this:

The final launch sequence is controlled by the Redundant Set Launch Sequencer - which according to Shuttle terminology should mean: By a piece of software running in all PASS GPCs of the GNC redundant set. This software is activated by the GLS at T-31 seconds. This software also controls the ignition sequence of the SSMEs, ignites the SRBs and triggers the pyros for the hold down bolts (Likely over the two master events controllers). The MECs also issue the command to retract the T-0 umbilicals.


The retraction of the Pre-T-0-arms (GOV vent and access arm) is triggered manually by LCC personal - which we simulate in the LCC vessel.

So, as interface between LCC/GLS and Shuttle (maybe via the MLP), we basically need the following interactions:

LCC to Shuttle (mostly over the two launch data buses, some stuff directly to LPC command decoders):
- Synchronize terminal count - set internal countdown time of the GPCs to the real countdown.
- Start RSLS control.
- Issue Go for main engine start (at T-10 seconds)
- HALT terminal countdown
- Power down LPS command decoder
- Lock out SRB MDMs

LCC to MLP:
- Arm Sound Suppression System
- Trigger Sound Suppression System

Shuttle to MLP:
- Retract T-0 umbilicals.
- destroy HDPs.

Shuttle to FSS:
- Retract GH2 vent line.

Shuttle to LCC:
- Halt countdown (RSLS abort)

Any criticism?

For the GOX venting, it might be good to have a function

virtual double GetETNoseVentMassFlow() const;

in the class Atlantis.

 

[GLS]

The retraction of the Pre-T-0-arms (GOV vent and access arm) is triggered manually by LCC personal - which we simulate in the LCC vessel.

I'm pretty sure that's all GLS commanded, but I'll check...