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#3600 by penguin44 on 28 Apr, 2019 05:19
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Question about rcs. I've noticed on the control panel that has a low-z selection. I know that this was used on docking to iss. How exactly does this work?
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#3601 by mkirk on 28 Apr, 2019 05:39
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Question about rcs. I've noticed on the control panel that has a low-z selection. I know that this was used on docking to iss. How exactly does this work?
“The LOW Z pbi (push button indicator) inhibits all up-firing jets from firing to prevent jet plumes from damaging payloads or Extravehicular Activity (EVA) crewmembers. If a +Z translation is required, +X and -X jets are commanded to fire since they have a small +Z thrust component. The -Z translations use the same six downfiring jets whether HIGH, LOW, or NORM Z is selected. The LOW Z pbi can be toggled on or off, is mutually exclusive with HIGH Z, and can be used regardless of the selection in the other translation axes.”
Mark Kirkman
Space Shuttle Hugger
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#3602 by penguin44 on 29 Apr, 2019 05:01
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Amazing. Thanks a lot! After all these years I had no idea that the +X and - X had a slight +Z to them.
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#3603 by Fequalsma on 30 Apr, 2019 10:30
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Ah got it now - I always wondered why there were no upfiring verniers.
F=ma
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#3604 by DaveS on 03 Jun, 2019 15:41
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Can someone clarify where the jettison line is for the Ku band DA? I have attached a photo of the DA of OV-103 with two lines, one red and one green. Which one is the correct one?
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#3605 by dror on 03 Jun, 2019 16:14
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What would a shuttle mission cost in CRS + CCTCap prices?
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#3606 by SWGlassPit on 03 Jun, 2019 16:30
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What would a shuttle mission cost in CRS + CCTCap prices?
I'm not sure I really understand the question -- it doesn't make a whole lot of sense to me.
Kind of like asking how many calories an apple would have if you made it out of bananas. -
#3607 by dror on 03 Jun, 2019 18:40
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What would a shuttle mission cost in CRS + CCTCap prices?
I'm not sure I really understand the question -- it doesn't make a whole lot of sense to me.
Kind of like asking how many calories an apple would have if you made it out of bananas.
sorry,
Assuming
1. shuttle could carry 20 ton to ISS, AND 7 crew members*
2. CRS prices are about 60-70$ million per ton*
3. CCTCap prices are between 30-50$ million per seat *
So a full shuttle mission would "worth" 1410-1750$ million.
If Shuttle prices were lower than that, does it mean that shuttle was more cost effective than COTS ?!
* My estimates are mostly unsubstantiated. I couldn't find formal prices or capabilities.
So I ask for better opinions
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#3608 by brickmack on 05 Jun, 2019 16:26
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What would a shuttle mission cost in CRS + CCTCap prices?
I'm not sure I really understand the question -- it doesn't make a whole lot of sense to me.
Kind of like asking how many calories an apple would have if you made it out of bananas. sorry,
Assuming
1. shuttle could carry 20 ton to ISS, AND 7 crew members*
2. CRS prices are about 60-70$ million per ton*
3. CCTCap prices are between 30-50$ million per seat *
So a full shuttle mission would "worth" 1410-1750$ million.
If Shuttle prices were lower than that, does it mean that shuttle was more cost effective than COTS ?!
* My estimates are mostly unsubstantiated. I couldn't find formal prices or capabilities.
So I ask for better opinions
Dragon-F9 is like 120 million total, for 6 tons to ISS, thats like 20 million per ton. That'd make a Shuttle flight "worth" more like 610-750 million, about the actual price of a Shuttle flight. Its probably a wash overall. If the CC/CRS vehicles flew as often, their price would probably come down though. Shuttle was definitely cheaper than equivalent Soyuz plus Progress/HTV/ATV cargo flights -
#3609 by DaveS on 06 Jun, 2019 22:07
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Q on the gussets that are on the sides of longerons of the orbiter PLB that connect with the Xo576 bulkhead: I'm having a hard time determining if they're are angled outboard at the points where they connect to the bulkhead. I have circled the structures in question, if there's any confusion as to what I am referring to.
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#3610 by Hog on 12 Jul, 2019 14:59
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Post STS-51-L, was their contingency plans that would have allowed crews to survive a Challenger type incident?
This is post 51-L so the crew is now in a pressure suit and would have been concious for the rest of the ride up and down.
Were there actual cue cards that would have instructed the crew to blow the hatch and egress a falling crew compartment? -
#3611 by Jorge on 12 Jul, 2019 15:55
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Post STS-51-L, was their contingency plans that would have allowed crews to survive a Challenger type incident?
This is post 51-L so the crew is now in a pressure suit and would have been concious for the rest of the ride up and down.
Were there actual cue cards that would have instructed the crew to blow the hatch and egress a falling crew compartment?
https://www.nasa.gov/centers/johnson/pdf/567068main_ASC_135_F_1.pdf
LOC/BREAK-UP cue card (PDF page 215) -
#3612 by jcopella on 14 Jul, 2019 03:33
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What did the Shuttle GLS user interface look like?
I'm building a simulator for the CCMS. I have a lot very detailed info on the OS and base applications (including the GOAL executor and FEPs) and even a pretty good idea how the GLS works (based on S0007 and the various GLSDD's that are floating around). Surprisingly, there's virtually no information out there about what the actual screens the console operators interacted with look like. I've found a single youtube video that briefly shows half of a barely visible screen here:
https://www.youtube.com/watch?v=R8aByl2fK5I?t=720 (skip to 12 minutes in)
From this video and a bit of guesswork I've reconstructed the display in the attached image. Does anyone know how accurate this is, and what should be on the right side of the screen?
It's very accurate. What's on the right side, if memory serves, are a few additional cursor targets to invoke other GLS tasks. I'd have to go back to my brain book to get the details.
I have some printed copies of the GOAL display skeletons (the static part of the display) that I can dig up if you're still interested in pursuing this project.
(I was a GLS operator during mid-life of the Shuttle program, 1989 thru 1993)QuoteA couple more specific questions:
- It looks to me like the top section with the timers is constant across all GLS displays, and the lower section is replaced depending on the particular GOAL program you're interacting with (SLP07 in this case). Is this right?
Yes.Quote- what do the marks under the VFY/MIP/LIP columns signify? I'm assuming the columns correspond to the state of mainline verifies, the mainline interrupt processor and LCC interrupt processors? Does it signify if there's a violation for that milestone?
That's correct. Each hash represents the state of a discrete pseudo function designator (FD) representing whether an inhibit (hold) against the given milestone has been flagged. These hashes were associated with cursor control points on the screen (tab stops, basically) so the operator could "cursor control" (tab) to them and turn them on/off manually, if needed. In practice, we never, ever had to do this, except in cases of software debug/test.Quote- what does 'ML REVERIFICATION' do? Is it a user invokable action?
I'm not 100% sure of this, because if memory serves (it has been a while), this was little-used, but yes, it was a user-invokable action. I believe what it did was scan all of the bookkeeping variables (these were 16-bit "digital pattern" pseudo FDs) for each milestone category to see if any inhibits (holds) were indicated in that category. Don't quote me on that, though -- my vague recollection is this was a feature that may have been needed in the early days but as the software and Shuttle itself matured, we outgrew the need for it.Quote- I'm guessing the 'BFS' and the top center is indicating the current ops? Should there be a matching 'PASS' mode next to it?
You would think so, wouldn't you? I'll check my printed copies and see if that section is accurate/complete.Quote- Although it's hard to see in the source image, above 'LAST HOLD' it looks like 'CPERS', which would be 'contingent performs'? Is that indicating whether any CPERS are currently running?
Precisely.Quote- similar to CPERS, I *think* that's 'TB0' in the lower right box, which would be 'Timebase zero'? is that just a display, or is it indicating something else?
Yes, that's the downlisted RSLS timebase zero value -- the number of seconds remaining until T-0, as determined by RSLS.QuoteThese are pretty obscure details to be worrying about, but I'm basically looking for any info to make this as accurate as possible. Any insight on what this or other GLS screens should look like or how they behave is greatly appreciated.
Thanks!
Sorry I'm just seeing this now -- had to do a search on GLSDD for another reason and found this post. Like I said, I have some hardcopies of the display skeletons that may be helpful to you if you are still engaged in this project.
p.s. Kudos to you on reverse engineering the semantics of that display from that grainy video and S0007. If you have access to Vol IV, you might find the GLS subsystem section which might provide some additional detail for not only SLP07, but the other GLS displays. As you've correctly surmised, SLP07 was just one of several. -
#3613 by daschmid on 16 Jul, 2019 21:24
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What did the Shuttle GLS user interface look like?
From this video and a bit of guesswork I've reconstructed the display in the attached image. Does anyone know how accurate this is, and what should be on the right side of the screen?
It's very accurate. What's on the right side, if memory serves, are a few additional cursor targets to invoke other GLS tasks. I'd have to go back to my brain book to get the details.
I have some printed copies of the GOAL display skeletons (the static part of the display) that I can dig up if you're still interested in pursuing this project.
(I was a GLS operator during mid-life of the Shuttle program, 1989 thru 1993)
Sweet! It's great to hear from someone with first hand experience. Some of your previous posts have been invaluable in figuring this stuff out.
I'm definitely still (slowly) working on it, and every bit of information is appreciated. I'm currently putting together a GOAL compiler/executor and using code automatically generated from parts of the GLSDD as my main test case. Of course, I'm entirely unsure that the code I'm generating is correct. I suspect, for example, that the VFY/CVFYs should be in tables rather than separate statements. GOAL is a weird language.
FYI for those interested, you can find electronic versions of GLSDDs for more than a dozen flights in the wayback machine here:
https://web.archive.org/web/19970609012138/http://lpsweb.ksc.nasa.gov/GLS/Dds/ddmenu.htmlQuotep.s. Kudos to you on reverse engineering the semantics of that display from that grainy video and S0007. If you have access to Vol IV, you might find the GLS subsystem section which might provide some additional detail for not only SLP07, but the other GLS displays. As you've correctly surmised, SLP07 was just one of several.
Thanks! And--yup. I've done several trawls through S0007 including Vol IV. Since the procedures are extremely detailed I've been able to glean quite a bit about the programs, screen contents, PFPK functions, etc. I've got a list of SAP, SGP and SLP programs I think are all part of GLS. (I'm not sure what they all do yet, but it's a start!)
Another high level question I've had: is the GLSDD the input that's used to generate the executable code, or is there a separate input file that generates both the GLSDD and executable code? I ask because there's enough variation that it's not always clear to me how to map entries in the GLSDD to GOAL statements. On the other hand, there are comments like "DELAY 2 SECONDS" that map directly.
Thanks again for your response; this is great!
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#3614 by jcopella on 23 Jul, 2019 22:46
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What did the Shuttle GLS user interface look like?
From this video and a bit of guesswork I've reconstructed the display in the attached image. Does anyone know how accurate this is, and what should be on the right side of the screen?
It's very accurate. What's on the right side, if memory serves, are a few additional cursor targets to invoke other GLS tasks. I'd have to go back to my brain book to get the details.
I have some printed copies of the GOAL display skeletons (the static part of the display) that I can dig up if you're still interested in pursuing this project.
(I was a GLS operator during mid-life of the Shuttle program, 1989 thru 1993)
Sweet! It's great to hear from someone with first hand experience. Some of your previous posts have been invaluable in figuring this stuff out.
I'm definitely still (slowly) working on it, and every bit of information is appreciated. I'm currently putting together a GOAL compiler/executor and using code automatically generated from parts of the GLSDD as my main test case. Of course, I'm entirely unsure that the code I'm generating is correct. I suspect, for example, that the VFY/CVFYs should be in tables rather than separate statements. GOAL is a weird language.
Yes, they are in tables, but perhaps not quite in the way you think -- see the rest of my reply, below.QuoteAnother high level question I've had: is the GLSDD the input that's used to generate the executable code, or is there a separate input file that generates both the GLSDD and executable code? I ask because there's enough variation that it's not always clear to me how to map entries in the GLSDD to GOAL statements. On the other hand, there are comments like "DELAY 2 SECONDS" that map directly.
Thanks again for your response; this is great!
In terms of automated code generation, the GLSDD was the input file to those tools; there was no other precursor file or automated process that produced the DD itself. Instead, the DD came about via the process of interpreting the LCC&B, the OMRSD, and the KSC LCC Implementation Plan. It was originally authored, and subsequently edited, entirely manually.
However, it's important to understand that the DD didn't generate *all* of the GLS, nor was all of the DD consumed by automated tools -- it was a hybrid kind of thing. The way the DD served automation of the GLS software was primarily in two areas: generation of the MIPs & LIPs and their associated "Lookup" programs (this was the infrastructure that supported the CVFY function), and generation of the GLS mainline (CMD and VFY and most of the activities that occurred between T-26m and post-launch securing).
Other parts of the GLS software -- for example, Safing -- were not automatically generated by the DD at all. The DD still served as the source of requirements, but Safing was entirely hand-coded.
Because of all this, you shouldn't think of a line item in the GLSDD as mapping onto a single GOAL statement; instead you should think of each GLSDD line item mapping onto a chunk of GLS architecture, which might be a single statement (as in the case of a delay), or many statements, potentially distributed across applications and processors (consoles). The latter was particularly true for CVFYs, which could get quite complicated and affected the Interrupt Processors (MIPs and LIPs), which ran at Backup, and the Lookups, which ran at Integration.
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#3615 by jcopella on 24 Jul, 2019 02:56
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Here are a couple of photos I snapped of pages in my brain book that might be helpful --
The first is of SDP01, the display skeleton for SLP07. Most elements should be obvious based on what you've been able to puzzle out so far, but if not, let me know and I'll try to help.
The second is kind of a "cheat sheet" or table of contents for all the GLS GOAL applications -- it might be helpful to associate a function with a program name you might see in the S0007 OMI, or whatever.
Good luck, and let me know how the project turns out!
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#3616 by fl1034 on 10 Aug, 2019 19:59
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Can someone explain why are there bellows on the turbine ends of HPFTP and HPOTP (in SSMEs of course)? What exactly are they loading onto the turbine? Is the whole stationary aft section free to shift axially inside the turbine housing, which includes the turbine inlet struts and all the stator blades? Then how is the clearance between this aft section and the turbine disc maintained? Through hydraulic pressure vs seal clearance?
Another quick follow-on, are all the turbines and stators uncooled and thus as hot as the fuel-rich gas? I've heard from non-authoritative sources that all these blades are coated with gold to mitigate hydrogen embrittlement. Is this true? -
#3617 by SWGlassPit on 14 Aug, 2019 14:01
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Can someone explain why are there bellows on the turbine ends of HPFTP and HPOTP (in SSMEs of course)? What exactly are they loading onto the turbine? Is the whole stationary aft section free to shift axially inside the turbine housing, which includes the turbine inlet struts and all the stator blades? Then how is the clearance between this aft section and the turbine disc maintained? Through hydraulic pressure vs seal clearance?
I don't have design knowledge, but from looking at illustrations, it appears the bellows serves the purpose of strain relief to allow for thermal expansion.QuoteAnother quick follow-on, are all the turbines and stators uncooled and thus as hot as the fuel-rich gas? I've heard from non-authoritative sources that all these blades are coated with gold to mitigate hydrogen embrittlement. Is this true?
The high pressure turbopump turbines are cooled with GH2, which is discharged into the turbine outlet. -
#3618 by fl1034 on 18 Aug, 2019 07:43
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I don't have design knowledge, but from looking at illustrations, it appears the bellows serves the purpose of strain relief to allow for thermal expansion.
That's what I thought also.The high pressure turbopump turbines are cooled with GH2, which is discharged into the turbine outlet.
How are the turbines cooled? Through internal labyrinthine GH2 passages? Or just by the GH2 leaked through the various seal between the shaft and the stators? -
#3619 by DaveS on 22 Aug, 2019 23:21
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Quick question to settle a discussion I'm having: The forward edges of the orbiter midbody sidewalls are perfectly vertical when seen from the side, is this correct? There's no angle to them? I'm talking about where the midbody joins with the lower forward fuselage half.
Edit:To make the question a bit more clear, is the interpretation of the attached schematic correct? Teal vertical line being the bottom of the Xo576 bulkhead, green horizontal line the PLBD hinge line at Zo420 and the red diagonal line the tilted upper section of the Xo576 bulkhead.
sorry,