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#1220
by
psloss
on 15 Aug, 2008 18:27
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I probably missed this or forgot where it was posted, but what are the TAL sites for the upcoming 28.5-degree inclination HST SM-4 launch? Since the last 28.5 mission (STS-109), Ben Guerir (BEN) and Banjul (BYD) were "deactivated" and the three sites that have been used since RTF are Zaragoza (ZZA), Moron (MRN), and Istres (FMI). However, these have all been high-inclination ISS rendezvous launches and I'm not sure that the shuttle could reach the higher latitude sites on a 28.5 launch.
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#1221
by
mkirk
on 15 Aug, 2008 21:37
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I probably missed this or forgot where it was posted, but what are the TAL sites for the upcoming 28.5-degree inclination HST SM-4 launch? Since the last 28.5 mission (STS-109), Ben Guerir (BEN) and Banjul (BYD) were "deactivated" and the three sites that have been used since RTF are Zaragoza (ZZA), Moron (MRN), and Istres (FMI). However, these have all been high-inclination ISS rendezvous launches and I'm not sure that the shuttle could reach the higher latitude sites on a 28.5 launch.
Moron is primary.
I haven't really given it any thought until you asked, and I don't know all the details, but as far as I know there will will be only one Primary TAL site - Moron - on launch day. BEN and BYD (no MLS) are still usuable as ACLS/ELS sites but will not be designated as potetential TAL sites.
Hopefully weather at MORON will cooperate...it is hard enough to get good TAL weather when there are 3 potential sites!
I will check on this further and if someone else knows better please feel free to correct me.
Mark Kirkman
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#1222
by
psloss
on 15 Aug, 2008 21:56
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Moron is primary.
I haven't really given it any thought until you asked, and I don't know all the details, but as far as I know there will will be only one Primary TAL site - Moron - on launch day. BEN and BYD (no MLS) are still usuable as ELS sites but will not be designated as potetential TAL sites.
Hopefully weather at MORON will cooperate...it is hard enough to get good TAL weather when there are 3 potential sites!
I will check on this further and if someone else knows better please feel free to correct me.
Mark Kirkman
Thanks for the details, Mark. After posting, I did find a couple of references to this, but any other details (like your note about no MLS) would be interesting. Having a single TAL site makes me a bit more curious about what other impacts (if any) that might have on ascent.
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#1223
by
mkirk
on 15 Aug, 2008 22:04
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Thanks for the details, Mark. After posting, I did find a couple of references to this, but any other details (like your note about no MLS) would be interesting. Having a single TAL site makes me a bit more curious about what other impacts (if any) that might have on ascent.
Well for starters it results in different abort boudaries with the first TAL capability coming a little later with Moron than if BYD or BEN were options.
Moron is achievable at around 800 to 1000 feet per second (in terms of shuttle velocity) later than BYD.
Thats not really too big of a deal since the program has already accepted that trade off in the past when the weather at the other two sites was not good enough
Mark Kirkman
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#1224
by
psloss
on 15 Aug, 2008 22:11
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Well for starters it results in different abort boudaries with the first TAL capability coming a little later with Moron than if BYD or BEN were options.
Moron is achievable at around 800 to 1000 feet per second (in terms of shuttle velocity) later than BYD.
Thanks, Mark; does this limit things like high-energy TALs or systems aborts? Or is it more of a matter of timing, as with the (two-engine) TAL boundary?
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#1225
by
gispa
on 17 Aug, 2008 17:53
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hi.. i read that during flyaround the rotational control of the orbiter is left to the DAP i would like to know the switches setting of the DAP thank u.....
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#1226
by
Jorge
on 17 Aug, 2008 18:47
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hi.. i read that during flyaround the rotational control of the orbiter is left to the DAP i would like to know the switches setting of the DAP thank u.....
The DAP is mostly controlled by pushbutton indicators (pbis) not switches.
DAP select pbi can be either A or B depending on pilot preference for large or small translational pulses (mostly A by the time of the flyaround).
DAP control pbi is in AUTO
Jet select pbi is VERN if available, PRI if VERN fail
LOW Z pbi is selected
Translational submode is always PULSE for all three axes
Rotational submode doesn't matter quite as much since the DAP is in AUTO, but most crews set them to DISC/DISC/DISC, all three axes.
See
http://www.nasa.gov/centers/johnson/pdf/216624main_RNDZ_123.pdfsection 2, especially blocks 8A and 9A.
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#1227
by
gispa
on 17 Aug, 2008 19:28
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thank you... for the reply
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#1228
by
Zoe
on 18 Aug, 2008 15:37
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#1229
by
rdale
on 18 Aug, 2008 16:34
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Hitting the "search" button and typing "Fairford" will show you quite a few posts already on that location...
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#1230
by
mkirk
on 18 Aug, 2008 16:36
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http://www.space-travel.com/reports/Fairford_Airmen_Prepare_For_Shuttle_Launch_999.html
Based on the trajectory of the shuttle, a TAL site is selected and the shuttle continues across the Atlantic Ocean. If the launch is aborted within 14 minutes of take off, RAF Fairford would be the site selected.
Fairford is not a TAL site so is the above link rubbish or would they be any reason for selecting Fairford?
Fairford is not a PRIME TAL site, but it does support very late, high energy, TALs. These are TAL aborts that could occur late in the shuttle's ascent. In the case of Fairford a landing may be achievable if the TAL abort occurs at velocities in the range of roughly 23,000 to 24,000 feet per second. These velocities are reached at about 8 minutes after launch which is shortly before the nominal MECO (main engine cutoff) timeframe of 8 minutes 30 seconds.
FFA is not usuable for TAL on STS-125 because it is a low inclination mission.
Mark Kirkman
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#1231
by
Zoe
on 18 Aug, 2008 21:52
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http://www.space-travel.com/reports/Fairford_Airmen_Prepare_For_Shuttle_Launch_999.html
Based on the trajectory of the shuttle, a TAL site is selected and the shuttle continues across the Atlantic Ocean. If the launch is aborted within 14 minutes of take off, RAF Fairford would be the site selected.
Fairford is not a TAL site so is the above link rubbish or would they be any reason for selecting Fairford?
Fairford is not a PRIME TAL site, but it does support very late, high energy, TALs. These are TAL aborts that could occur late in the shuttle's ascent. In the case of Fairford a landing may be achievable if the TAL abort occurs at velocities in the range of roughly 23,000 to 24,000 feet per second. These velocities are reached at about 8 minutes after launch which is shortly before the nominal MECO (main engine cutoff) timeframe of 8 minutes 30 seconds.
FFA is not usuable for TAL on STS-125 because it is a low inclination mission.
Mark Kirkman
So would a TAL abort to Fairford only be needed if all 3 engines were out as by that time they would be single engine press?
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#1232
by
mkirk
on 19 Aug, 2008 18:34
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So would a TAL abort to Fairford only be needed if all 3 engines were out as by that time they would be single engine press?
Well as always there is no simple answer – at least I don’t have one. Part of the problem is the terms TAL, Late TAL, High Energy TAL, and Last TAL are used interchangeably although they actually have different and specific meanings.
For the most part what we are talking about in the case of Fairford (FFA) is a Last TAL capability which is intended to manage the gap between AOA capability and Late Auto Guidance TALs.
So to answer your specific question, it not always just about performance problems (i.e. loss of some or all engines etc…) but also some systems problems that would make pressing on uphill highly undesirable. There are scenarios where MECO would be intentionally commanded by the crew in order to stay within the velocity range/velocity window for the intended landing site.
I’m not sure what the Shuttle Program’s most current philosophy is but I can say that the decisions on what course of action to take are based on the risk trades of attempting a TAL, bailing out, or attempting an AOA.
I should add that it was this part of the ascent timeline that was of particular concern when the Shuttle Program was looking at dealing with certain ECO (engine cutoff) sensor failure modes.
Mark Kirkman
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#1233
by
fcmadrid
on 21 Aug, 2008 16:38
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Hello!
Can someone please tell me how much energy is needed to lift off the space shuttle or released?
thank you
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#1234
by
rdale
on 23 Aug, 2008 17:18
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#1235
by
gispa
on 24 Aug, 2008 14:05
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a question... why in the orbiter cockpit there are indication for the ssmes ,for example during liftoff ,and not for the srbs? THANK U
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#1236
by
Jim
on 24 Aug, 2008 14:18
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a question... why in the orbiter cockpit there are indication for the ssmes ,for example during liftoff ,and not for the srbs? THANK U
Because it isn't needed. There is nothing the crew can do if only one SRB lights. Also they have other indications when they light (sound, accel, etc) and the MET clock is counting past T+0.
The crew does get a "Pc<50" indication on the CRT's when the SRB's are burning out.
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#1237
by
gispa
on 24 Aug, 2008 15:16
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thank you... Jim
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#1238
by
Opie
on 26 Aug, 2008 17:16
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What are the temperatures inside and outside the boundary layer of the shuttle during reentry?
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#1239
by
rdale
on 26 Aug, 2008 17:34
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