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#1000
by
joema
on 20 May, 2008 13:41
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mkirk - 19/5/2008 9:12 PM
I will have to double check but I am pretty sure FAST SEP (form the entire stack) is commanded just prior to the time that SRB SEP would occur PC<50 + 2 seconds (nominally SRB SEP is PC<50 + 5 seconds). This is done owith the BFS because the setting of MECO Confirmed negates the PASS SRB SEP Sequence....
I don't have detailed info on that. I was going by what Andy Foster (former ascent procedures specialist) said regarding the ET strut reinforcement and separation sequence. It could be wrong or misunderstood.
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#1001
by
C5C6
on 20 May, 2008 14:50
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I rember asking user charlieb about blue-3 abort.....because I wonder if the RCS or OMS could provide some attitude control to prevent a disaster......
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#1002
by
pr1268
on 20 May, 2008 20:30
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Shuttle telemetry data rates during launch, orbit, and re-entry: Is there a measure of telemetry data rates for any given flight mode of the Shuttle, e.g., X bits per second total telemetry during launch/ascent, etc.? I'm just curious; a ballpark figure would satisfy my curiosity. Thanks!
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#1003
by
NavySpaceFan
on 21 May, 2008 21:20
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Where can I get an orbiter flag (like the ones that fly under the colors at the pad and press area), especially a DISCOVERY flag? Thanks!!!
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#1004
by
DaveS
on 22 May, 2008 15:44
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Pad question: What are those pipes that goes around the top near the "garage door" of the RSS? Is it some sort of purge ducting for the PCR?
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#1005
by
Jim
on 22 May, 2008 17:14
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DaveS - 22/5/2008 11:44 AM
Pad question: What are those pipes that goes around the top near the "garage door" of the RSS? Is it some sort of purge ducting for the PCR?
Do you have a pic?
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#1006
by
DaveS
on 22 May, 2008 18:01
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Jim - 22/5/2008 7:14 PM
DaveS - 22/5/2008 11:44 AM
Pad question: What are those pipes that goes around the top near the "garage door" of the RSS? Is it some sort of purge ducting for the PCR?
Do you have a pic?
I hope this one will do. I'm talking about the red/white pipes.
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#1007
by
Jim
on 22 May, 2008 18:19
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AC ducts
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#1008
by
DaveS
on 22 May, 2008 18:32
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Jim - 22/5/2008 8:19 PM
AC ducts
OK, same deal with the large pipes on the back of the RSS?
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#1009
by
mkirk
on 22 May, 2008 21:08
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joema - 20/5/2008 8:41 AM
mkirk - 19/5/2008 9:12 PM
I will have to double check but I am pretty sure FAST SEP (form the entire stack) is commanded just prior to the time that SRB SEP would occur PC<50 + 2 seconds (nominally SRB SEP is PC<50 + 5 seconds). This is done owith the BFS because the setting of MECO Confirmed negates the PASS SRB SEP Sequence....
I don't have detailed info on that. I was going by what Andy Foster (former ascent procedures specialist) said regarding the ET strut reinforcement and separation sequence. It could be wrong or misunderstood.
Foster was their way before my time. I believe you can read about him in the book “Before Liftoff” by Henry Cooper. The book – which is very dated – describes the training of Bob Crippen’s STS-41G crew. Ironically – at least for me – Crippen’s daughter was one of the Ascent Procedures Specialists when I worked in the training group.
You may have misunderstood some of what Andy told you. I did review the procedures and know that my memory is coming back I can confirm that what I said earlier about the SEP sequence is correct.
As for the aft struts I really don’t know. There hasn’t been anything done to them in the last few years as far as I know. Andy may have been talking to you about discussions/proposed changes/actual changes that occurred after 51L.
Mark Kirkman
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#1010
by
mkirk
on 22 May, 2008 21:09
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C5C6 - 20/5/2008 9:50 AM
I rember asking user charlieb about blue-3 abort.....because I wonder if the RCS or OMS could provide some attitude control to prevent a disaster......
For 3 Out Blue the RCS is used when SERC (Single Engine Roll Control) is invoked during SRB thrust tail off. SERC was intended to help maintain control of the Orbiter/ET stack when only one SSME is burning. Since attitude control – after SRB SEP – is nominally maintained by gimbaling the SSMEs, you no longer have enough control authority in a single SSME scenario. For this reason SERC was developed to allow the RCS to help maintain attitude control.
In a 3 Out Blue case you obviously do not have any SSMEs burning – and therefore no thrust vector control – but the SERC logic is still useful in maintaining attitude control during the SEP SEQUENCE.
Once the orbiter is away from the stack the GPCs will be operating Entry logic/software and the RCS and Flight Control System will be used as appropriate.
An OMS dump (i.e. burn) usually takes place in these scenarios when the abort is declared – depending on the time the abort is initiated – to help with cg (center of gravity) control. The OMS engine are not really being used in this case for additional thrust or attitude control.
Mark Kirkman
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#1011
by
psloss
on 22 May, 2008 22:11
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mkirk - 22/5/2008 5:08 PM
Foster was their way before my time. I believe you can read about him in the book “Before Liftoff” by Henry Cooper. The book – which is very dated – describes the training of Bob Crippen’s STS-41G crew. Ironically – at least for me – Crippen’s daughter was one of the Ascent Procedures Specialists when I worked in the training group.
He also had a great online reference on shuttle aborts with illustrations and cue-cards, which has since disappeared (at least in "live" form).
I don't remember where I saved them, but Charlie Precourt did a presentation to the Shuttle Development Conference in 1999 that I believe referenced the 3 EO / ET struts issue...can't remember what exactly the "disposition" of it was, though. Only the slides were available online, which I presume were just an outline of the presentation. That site has also disappeared.
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#1012
by
mkirk
on 22 May, 2008 22:30
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psloss - 22/5/2008 5:11 PM
I don't remember where I saved them, but Charlie Precourt did a presentation to the Shuttle Development Conference in 1999 that I believe referenced the 3 EO / ET struts issue...can't remember what exactly the "disposition" of it was, though.
Yeah, I remember all of that stuff but back then we thought we were going to get things like the new APUs, Non Toxic RCS, Cockpit Avionics Upgrade, Forward RCS Interconnect, etc...
Mark Kirkman
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#1013
by
Jim
on 23 May, 2008 00:13
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DaveS - 22/5/2008 2:32 PM
Jim - 22/5/2008 8:19 PM
AC ducts
OK, same deal with the large pipes on the back of the RSS?
yes
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#1014
by
joema
on 23 May, 2008 13:40
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psloss - 22/5/2008 5:11 PM
...Precourt did a presentation to the Shuttle Development Conference in 1999 that I believe referenced the 3 EO / ET struts issue...can't remember what exactly the "disposition" of it was, though. Only the slides were available online...
Some of the slides were ascent event/velocity charts from different periods during the program. They showed the large difference in black zones before & after 51L, also in recent years.
There were three relevant slides: black zones pre-51L, post-51L, and current (circa 1999). Pre 51L, there were large black regions. With the post-51L improvements, the black zones were a lot smaller.
However -- abort enhancements continued, and the black zones further decreased even after the 51L improvements. This was shown on the 3rd slide.
Unfortunately I don't have the slides, but it illustrates looking at a "black zone" chart from (say) 1988 doesn't necessarily reflect the capability of the current vehicle.
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#1015
by
ChrisC
on 23 May, 2008 15:36
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Question for you all ... In camera 063 today, I see a shot looking down at the SRB skirts and MLP. This morning they installed some sort of large red water bladders over the MLP space adjacent to the SRBs. What are those for? I'm guessing something to do with flame control or acoustic suppression. Attached is a tiny screenshot.
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#1016
by
psloss
on 23 May, 2008 15:44
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ChrisC - 23/5/2008 11:36 AM
Question for you all ... In camera 063 today, I see a shot looking down at the SRB skirts and MLP. This morning they installed some sort of large red water bladders over the MLP space adjacent to the SRBs. What are those for? I'm guessing something to do with flame control or acoustic suppression. Attached is a tiny screenshot.
Yes:
http://www.nasa.gov/returntoflight/launch/red_water_sausages.html(Usually a good indicator that the countdown is fairly near...)
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#1017
by
ChrisC
on 23 May, 2008 16:18
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thanks!
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#1018
by
thomasafb
on 24 May, 2008 00:52
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Maybe it's lack of sleep, but when looking through the entry checklist just now on 5-2 there is a reference to the EMER PWRDN Cue Card and i just can't find it. Anybody know where to look for it? Thanks!
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#1019
by
mkirk
on 24 May, 2008 06:56
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thomasafb - 23/5/2008 7:52 PM
Maybe it's lack of sleep, but when looking through the entry checklist just now on 5-2 there is a reference to the EMER PWRDN Cue Card and i just can't find it. Anybody know where to look for it? Thanks!
A copy can be found in the Mulit Phase Cue Cards section of the AESP (Ascent/Entry Systems Procedures) Checklist.
I can't remember for sure but it may also be in the Pocket Checklists.
Mark Kirkman