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#1800 by roma847 on 11 Apr, 2020 00:17
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Hello everybody,
unfortunately there are a few inconsistencies regarding the front and back of the ET/SRB Forward Attachment, which still seem suspicious to me.
On the left during the Rollout of the ET-8 (STS-6) one can clearly see the FWD Hoisting Lug sitting on the "front side" of the ET and pointing up , and on the right, what also shows the ET-8 "front side" it looks like the arrangement with the ET/SRB RSS cross-wiring, strange ...
That doesn't go together ...
The same arrangement can be seen in this photo from the STS-8,
Source: forum.nasaspaceflight.com (Ares67)
as well as from the STS-9 too.
Source: NASA
Both arrangements would correspond with that of the STS-6 (first image, right).
On the other hand, there are no holes on the FWD Hoisting Lug (right) for the assembly of the ET/SRB RSS cross-wiring boxes, which one can see in the left image.
Source: forum.nasaspaceflight.com (Jester) Source: live.staticflickr.com (S. Patlan)
But in this screenshot from a Pad 39A walkdown video taken during the STS-133 pad flow it can be seen that these ET/SRB wiring boxes (with a gray fairing) are not sitting on the "front" but on the "back" of the ET (the side that facing away from the orbiter). Now the expert is amazed, and the layperson wonders, right?
This view shows up at 2:36, here you go!
How does that fit together, or not, what do you think about it?
Maybe someone here in NSF knows about this matter?
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#1801 by roma847 on 16 Apr, 2020 21:08
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Hello everybody,
in our German Raumcon Forum I received a tip about the "Space Shuttle Technical Conference" from 1985, the both parts of which I found on the NASA Technical Reports Server (NTRS)
and have skimmed over Easter. Part 1 (227 MB) - Part 2 (198 MB) ... 
Unfortunately, I could not find any information in order to clarify the said discrepancies regarding the ET/SRB Forward Attachments, which I have noticed on some early missions' photos.
Regardless of this, one can find a wealth of interesting information in the conference contributions, which I have looked at here and there in more detail, provided that they did concern the ET and/or the SRBs and contained corresponding photos.
And so I'm among others came across a Term I had been tampering with for a while already without getting to the bottom of it ...
This is the term RSS Fairing, which was most recently used in this drawing of the Forward attachment.
Source: System Definition Handbook SLWT, Vol. II (Lockheed Martin)
The term Fairing as such was already familiar to me from the front fairings of the LO2 Feedline and the GH2 Press. Line on the Intertank.
I was only irritated by the abbreviation RSS, which I'm of course familiar regarding the Rotating Service Structure, but wich has nothing to do with it.
But as I have now learned from a conference contribution (EXTERNAL TANK PROCESSING FROM BARGE TO PAD), with RSS is meant the so-called Range Safety System, which I did not know so far, but which was of extraordinary importance as a safety system for all shuttle missions.
And as it is often the case, I was so interested that I pursued this in a targeted manner and tried to find out more information about the task and function of the RSS.
With this is also related to the term ET/SRB RSS cross-wiring, which my friend DaveS from the NSF mentioned during a lengthy PM chat, which only increased my curiosity.
And with that we are right back to these white boxes on the "front" of the ET/SRB Forward Attachment,
which can be seen here both in the opened and in the cladded state, the upper half of which belongs to the ET and the lower half to the SRB. In the left image one can see the RSS cabling between the ET and the SRB for the STS-103.
The Space Shuttle's Range Safety System (RSS) thus enables the destruction of both the SRBs and the ET using on-board explosive charges (Linear Shaped Charge, LSC) by radio remote control from the ground station by the Range Safety Officer (RSO) in the event that the shuttle stack gets out of control to limit the danger to people and facilities on the ground from crashing pieces, explosions, fire, poisonous substances, etc. ...
This drawing shows these LSCs on the ET/SRB, as well as the associated receiving antennas, the Range Safety Command Antennas.
Source: NASA
The RSS was only connected to the LSCs, but not to the SRB separation system, which was wired separately.
As I also know by DaveS, the RSS was cross-wired for security reasons, so that an error could not impair the ability to destroy the stack. The cross-wiring ran from the left SRB-RSS through the ET to the right SRB-RSS and vice versa. In this way, failure of one SRB's RSS cabling would not affect its ability to be destroyed, since the security cabling always was ran from the other SRB too.
The RSS was activated only once - during the Challenger disaster (STS-51-L), 37 seconds after the orbiter broke apart when the SRBs were in uncontrolled flight (Source: wikipedia.org).
And with that once again back to the above-mentioned discrepancies regarding the ET/SRB Forward Attachments.
These can only be explained by the fact that the RSS cross-cabling in the early missions was probably more done on the "front" (-Z side) of the ET than on the "back" (+Z side).
So much for my little Easter walk for those interested.
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#1802 by HDTVGuy on 23 Apr, 2020 00:12
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Once you get to the page with the Technical Conference Manuals, scroll down to the link for "all child document records". It takes you to a link for 44 more shuttle manuals.
Happy Reading. -
#1803 by HDTVGuy on 23 Apr, 2020 13:28
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The "child" documents are different for Part 1 and Part 2.
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#1804 by roma847 on 23 Apr, 2020 20:26
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Thanks for the hint,
these are the individual contributions of the conference.
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#1805 by roma847 on 29 Apr, 2020 13:30
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Hello everybody,
after a longer breather I want to get back in so that I can’t get out of the exercise.
Therefore I want to leave the SRBs for the time being and address myself to the ET to start preparing him for the Flour coating, wherefore I first have to glue the tape strips for simulating the SOFI Pattern texture both on the LH2 Tank and on the LO2 Tank.
For this I can resort to my preliminary tests from last year, in which I used a 0,75 mm wide tape strip as a continuous spiral (Barber pole) onto the Airfix Intertank which is no longer required,
which at the time looked like this after the Flour coating.
So I came very close to the pattern texture of the ET-8, whereby the final result should probably look even a bit better after priming and painting.
As one could see at this image, the SOFI patterns on the ET Aft Dome are significantly wider than on the front part of the tank, which I wanted to take into account.
Source: forum.nasaspaceflight.com (Jester)
After taking a closer look at this structure once more, I decided to use 1,5 mm wide tape strips, of which I've then glued short strips on the Aft Dome at intervals of about ≤ 1 mm for testing. Before that, of course, I had removed my fragile Aft ET/Orbiter Attachment and put it in a box to safety.
On the front part there are glued the chosen 0,75 mm wide strips, at intervals of approx. 0,5 mm.
So I could imagine that way.
What do you think about it?
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#1806 by roma847 on 30 Apr, 2020 20:13
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Hello everybody,
in other forums doubts were expressed as to whether this gluing of an Endless barberpole tape spiral on the LO2 Tank may prove difficult due to the tapered curvature, what does not appear as impossible.
Well, on the LO2 Tank I actually wanted to do it exactly this way, and I don't think there should be any major problems, especially because the 0,75 mm wide tape is very thin and stretchy, so it should nestle easily against the tank bulge.
In this photo of the ET-33 (STS-36) by George Gassaway the typical SOFI Pattern Texture is clearly too see,
Source: georgesrockets.com
as also in this photo of the ET-8, which of course interests me more, in which I had tried to count the rings at the time, which was pure stress for my tired eyes.
Source: forum.nasaspaceflight.com (Jester)
But my preliminary tests at that time have encouraged me to try again.
Doing this, in general the difficulty is to keep the same distance between the turns as possible when gluing the tape spiral, which I will hopefully manage.
However, on the ET's back on the Aft Dome there might be problems since the 1,5 mm wide tape to be used there is twice as wide, so that the windings due to the decreasing radius in the center could be more difficult to glue , which could lead to small folds.
But I will definitely try that, and then let's have a look ...
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#1807 by roma847 on 30 Apr, 2020 20:49
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Hello friends,
I've tried it on the Aft Dome, which is actually not immediately satisfactory, since the 1,5 mm tape on this flat bulge with decreasing radii is increasingly difficult to bend and consequently fits less smoothly, which then leads to small wrinkles, which of course do not appeal to me. 
A little remedy can be provided by carefully cutting into the wrinkles with the razor blade and then pressing them flat, which I did here in the middle area above the Man Hole.
But that's also not yet exactly brilliant, I think at least ...
With the 0,75 mm tape, this should probably look different on the LO2 Tank, i.e. a little bit better.
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#1808 by roma847 on 01 May, 2020 21:15
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Hello everybody,
today fitting to the topic of SOFI Pattern Texture, here once again a small quiz question.
Most of you already know this item on the right, this is a piece of SOFI Insulation Foam from the External Tank ET-138 flown on the last mission, STS-135, that my friend Scott Phillips has gifted me.
But what could that be on the left in the picture?
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#1809 by roma847 on 02 May, 2020 17:00
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Hi friends,
no guess or no fancy?
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#1810 by SteveGoodey on 03 May, 2020 06:41
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A piece of orbiter TPS?
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#1811 by roma847 on 03 May, 2020 10:43
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Hey Steve, Bingo!!!
This is a piece of a Heat protection tile from the Thermal Protection System (TPS) used for the Shuttle, which a friend from our Raumcon Forum has gifted to me as a small present from his visits to the KSC, with which he made a great pleasure to me.
If one takes the material in hand, one will immediately notice the low weight, which is no wonder with a pore content of approx. 90%.
This is a complete TPS Tile that has a top layer of Borosilicate that withstands temperatures from 1200 to 1600 °C, underneath there is this material of sintered Silica glass fibers (SiO2), of which now a piece enriches my rarity collection.
Source: wikipedia.org
Source: wikipedia.org
And to match this, the following two spectacular videos demonstrating the amazing properties of this material.
This photo is already a little taste of it. 
Source: geek.com/news (Ryan Whitwam)
So much for this hot topic.
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#1812 by roma847 on 03 May, 2020 15:57
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Hello my friends,
in the meantime I have still thought and tried out another variant with two 0,75 mm tapes glued next to each other, which intuitively should work better on the flat curve of the Aft Dome.
After I had removed the previously glued 1,5 mm tapes, this time I started on the inside at the smallest ring and first of all glued the 0,75 mm tape from the roll on the marked circle, piece by piece, and always firmly pressed on tightly, with the tank in the left hand and the tape roll in the right hand. Then I glued the next tape ring right next to the first ring, which was a bit easier because the tape did let easy nestle to it. 
Since from now on it was important to keep the spacing of the double rings as uniform as possible, I glued four small pieces of the 0,75 mm tape as a spacer for better orientation and then glued the next ring, relying on my sharp eagle eye during the following quarter turns, until the next spacer came into view. 
And so I've laboriously rolled out ring by ring, which was quite a torture for my eyes,
so that I had to take a few breaks. 
And then it was finally done, and I was done too, and the result is actually as I had imagined it and looks well, in my opinion.
With these positive impressions I went to bed early in the morning ...
And here are still a few pics in daylight.
This time indeed it was twice the effort, but the heck with it, it was worth it ...
The Lord of the Rings says hello and wishes all a nice Sunday.
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#1813 by mike robel on 05 May, 2020 13:10
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Excellent Craftsmanship, Manfred. Awesome (a word I use very seldom).
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#1814 by roma847 on 05 May, 2020 15:21
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Thanks Mike for your great compliment, what I really treasure.
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#1815 by roma847 on 05 May, 2020 19:08
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Hello everybody,
here's already a little tast of what's coming up now to me, namely the rest of the LH2 Tank, on which approx. 130 Tape rings are to be glued as an endless spiral (Barber pole).
BTW, it means, that a whole roll of 25 m tape will actually go on for this procedure, which is why I had to reorder one roll for the LO2 Tank once more.
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#1816 by SteveGoodey on 06 May, 2020 07:23
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Good luck, hope it goes well and that your eyes and sanity survive.
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#1817 by EG on 06 May, 2020 08:54
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Good luck, hope it goes well and that your eyes and sanity survive.
I have plenty of faith in Manfred's ability to pull this off, of course I've already seen him do it.... :-) -
#1818 by roma847 on 06 May, 2020 10:02
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Good luck, hope it goes well and that your eyes and sanity survive.
Thanks Steve,
then keep your fingers pressed
and stay tuned. 
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#1819 by roma847 on 06 May, 2020 10:06
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Good luck, hope it goes well and that your eyes and sanity survive.
I have plenty of faith in Manfred's ability to pull this off, of course I've already seen him do it.... :-)
Thanks EG for your nice support,
you've known me for a while ... and I don't want to disappoint you.
