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

[DaveS]

News on the ascent front: It seems launching from VAFB yields the expected "Hi-Q" numbers. I generated a mission file and scenario for the first VAFB mission (STS-62A/1V) and used BrianJ's Sunnyvale STS Missions add-on for the payloads. And tbe launch went well, with a recorded Q-value of ~725 psf.

I wonder if the Ascent guidance is anything differently for launches from VAFB? Are missing something at KSC?

 

[Urwumpe]

News on the ascent front: It seems launching from VAFB yields the expected "Hi-Q" numbers. I generated a mission file and scenario for the first VAFB mission (STS-62A/1V) and used BrianJ's Sunnyvale STS Missions add-on for the payloads. And tbe launch went well, with a recorded Q-value of ~725 psf.

I wonder if the Ascent guidance is anything differently for launches from VAFB? Are missing something at KSC?

No idea, would need to check. I would expect a different guidance profile since the relative velocity at liftoff is lower.

I still work on sorting the RSLS code. Maybe I will replace the current version by a new one and make it a lot easier to read.

 

[DaveS]

Did another run of STS-62A, got a slightly higher Q-value this time, 778 psf at T+50.5. The slightly higher Q-value can probably be attributed to removal of the RMS (it wasn't going to be manifested on 62A) which I had left in for the first run.

 

[Urwumpe]

Did another run of STS-62A, got a slightly higher Q-value this time, 778 psf at T+50.5. The slightly higher Q-value can probably be attributed to removal of the RMS (it wasn't going to be manifested on 62A) which I had left in for the first run.

Where was the red line? Maybe we need a different thrust bucket I-LOAD then.

 

[DaveS]

Where was the red line? Maybe we need a different thrust bucket I-LOAD then.

Thrust bucket is identical between KSC and VAFB, down at 792 and up at 1304. Third run now with slightly tweaked MECO targets had a Q of 778.7 psf at T+50.2.

 

[Gingin]

That also might come from different I-loaded stage 1 closed loop pitch / pitch rate tables ( Payload/ CoG / Inclination etc dependant) .

I just found two of them, maybe you have more informations about them.

Latest one from Ascent Guidance Workbook ( I think the one implemented in SSU)

Table for STS 1

 

[DaveS]

Do you happen to know if the one from the Ascent Guidance Workbook is for Lo-Q or Hi-Q profile? First Hi-Q flight was STS-95 in October 1998. All the flights until STS-93 in July 1999 used Hi-Q. Then the next Hi-Q mission was STS-99 in Feb. 2000. All missions except for STS-121 in July 2006 used Hi-Q. STS-121 used Lo-Q for a one-time flight load reduction on the now exposed sections of the ET press-lines and cable trays after the removal of the two Protuberance Air Load (PAL) aero ramps.

 

[Gingin]

Do you happen to know if the one from the Ascent Guidance Workbook is for Lo-Q or Hi-Q profile?

Not precisely .
The workbook revision is the latest one from 2006, I guess the Stage 1 table advertised is close to the one used for latest Shuttle flights.
They speak also about the adaptative logic for SRB hot or cold conditions, and unforseen winds shifts ( load alleviation)
Also there are interesting things about one or two stage buckets.

You might find that workbook and the ascent/abort Handbook ( deeper subjects about stage 1 )in the L2 part of Nasaspaceflight.com if you are interested.


I found some public links on older version of those Work/Handbooks

Ascent Guidance Workbook 1979

Ascent Abort Handbook 1981

 

[gattispilot]

Not sure if this is right place. I am trying to compile using VS2019 Community version

I get this error:
Severity Code Description Project Path File Line Suppression State
Error MSB8036 The Windows SDK version 10.0.17763.0 was not found. Install the required version of Windows SDK or change the SDK version in the project property pages or by right-clicking the solution and selecting "Retarget solution". SSU_IUS C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160 C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160\Microsoft.Cpp.WindowsSDK.targets 46

 

[DaveS]

That's an easy one to fix. Just fire up your VS Installer, and click on Modify in the VS2019 Community field. Then if it isn't already open, open the Optional tree in the right-hand pane where it says Installation details. Then scroll down and check Windows 10 SDK (10.0.17763.0). Then click on the Modify button. It will now download install the correct Win SDK version.

 

[gattispilot]

Thanks. OPen the VS installer and Open the Optional tree. But this is all I see:

Will I need to change it back for other projects?

 

[DaveS]

Weird. Try going to Individual components and do a search for it there.

 

[gattispilot]

So I updated

but now I get these:
Severity Code Description Project Path File Line Suppression State
Error MSB8020 The build tools for Visual Studio 2017 (Platform Toolset = 'v141') cannot be found. To build using the v141 build tools, please install Visual Studio 2017 build tools. Alternatively, you may upgrade to the current Visual Studio tools by selecting the Project menu or right-click the solution, and then selecting "Retarget solution". Atlantis C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160 C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160\Microsoft.CppBuild.targets 411
Error MSB8020 The build tools for Visual Studio 2017 (Platform Toolset = 'v141') cannot be found. To build using the v141 build tools, please install Visual Studio 2017 build tools. Alternatively, you may upgrade to the current Visual Studio tools by selecting the Project menu or right-click the solution, and then selecting "Retarget solution". Atlantis_Tank C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160 C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160\Microsoft.CppBuild.targets 411

 

[DaveS]

Install the MSVC v141 - VS 2017 C++ x64/x86 build tools. It's possible that we have some old VS 2017 stuff left.

 

[gattispilot]

Thanks. I am not finding that to install I selected the windows sdk 10.0.17763.0. and compiled. now I just get it for the tank
Severity Code Description Project Path File Line Suppression State
Error MSB8020 The build tools for Visual Studio 2017 (Platform Toolset = 'v141') cannot be found. To build using the v141 build tools, please install Visual Studio 2017 build tools. Alternatively, you may upgrade to the current Visual Studio tools by selecting the Project menu or right-click the solution, and then selecting "Retarget solution". Atlantis_Tank C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160 C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160\Microsoft.CppBuild.targets 411

 

[DaveS]

What versions of VS 2019 and the Installer are you running. Latest is for VS2019 is 16.9.4 and the Installer is 2.9.3365.

 

[gattispilot]

Microsoft Visual Studio Community 2019
Version 16.7.2
updating now

 

[DaveS]

The installer version can be seen in the lower right corner of the first screen.

 

[gattispilot]

I undated to
Microsoft Visual Studio Community 2019
Version 16.9.4 and installer is : Installer version 2.9.3365
I selected the windows sdk and built. get this error:
Severity Code Description Project Path File Line Suppression State
Error MSB8020 The build tools for Visual Studio 2017 (Platform Toolset = 'v141') cannot be found. To build using the v141 build tools, please install Visual Studio 2017 build tools. Alternatively, you may upgrade to the current Visual Studio tools by selecting the Project menu or right-click the solution, and then selecting "Retarget solution". Atlantis C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160 C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160\Microsoft.CppBuild.targets 439

 

[DaveS]

You still need to install the VS 2017 build tools I told you about earlier. The updating was just in case an old version was preventing you from seeing them in the installer.