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#2120
by
Jorge
on 09 Aug, 2011 00:24
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Orginally, PASS was written by IBM and BFS by Rockwell. It is completely different and only handles the primary flight regimes
To add, PASS and BFS remained under separate groups to the end. PASS ended up with USA and BFS with Boeing.
BFS supported only ascent/entry and basic orbit coast (i.e. no rendezvous or prox ops). It did not support all modes during ascent/entry either. Ascent BFS was auto only (no manual takeover capability) while entry BFS was manual only (no auto flight control). Until very close to the end of the program BFS did not support the HUD, or any approach/landing guidance below 1500'.
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#2121
by
elmarko
on 09 Aug, 2011 08:41
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Why was that, Jorge? Why were those things left till late in the program to change?
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#2122
by
clevelas
on 10 Aug, 2011 15:09
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Thanks Jim and Jorge. Great information. Sounds like it was kept pretty simple and just intended to give you a chance to make it back home.
The more in-depth I get with orbiter operations, the more I'm amazed at how much the commander really has to know his/her stuff. A lot of 'if we're in this mode, do this. if in that mode, do that'.
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#2123
by
spacecane
on 10 Aug, 2011 21:09
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Does anybody have any recollection of the following or know what the proposal actually was? When I was a kid (I'm pretty sure before Challenger) I saw a magazine with drawing that from memory was additional engines at the bottom of the ET. It almost looked like the Ares V/SLS but with the orbiter still there. I know I saw it, the only question in my mind was if this was something real or a mistake made by the magazine that confused some kind of Shuttle Derived vehicle?
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#2124
by
JayP
on 10 Aug, 2011 21:53
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Does anybody have any recollection of the following or know what the proposal actually was? When I was a kid (I'm pretty sure before Challenger) I saw a magazine with drawing that from memory was additional engines at the bottom of the ET. It almost looked like the Ares V/SLS but with the orbiter still there. I know I saw it, the only question in my mind was if this was something real or a mistake made by the magazine that confused some kind of Shuttle Derived vehicle?
That sort of sounds like the Sigma EDIN05 concept.
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#2125
by
wolfpack
on 10 Aug, 2011 22:57
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Orginally, PASS was written by IBM and BFS by Rockwell. It is completely different and only handles the primary flight regimes
The shuttle never actually flew on BFS, right?
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#2126
by
Jim
on 10 Aug, 2011 23:37
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Does anybody have any recollection of the following or know what the proposal actually was? When I was a kid (I'm pretty sure before Challenger) I saw a magazine with drawing that from memory was additional engines at the bottom of the ET. It almost looked like the Ares V/SLS but with the orbiter still there. I know I saw it, the only question in my mind was if this was something real or a mistake made by the magazine that confused some kind of Shuttle Derived vehicle?
That was the LBM (Liquid Boost Module). It was replaced by filament wound cases for VAFB.
If you have L2, it is here
http://forum.nasaspaceflight.com/index.php?topic=20427.0
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#2127
by
elmarko
on 11 Aug, 2011 08:46
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Orginally, PASS was written by IBM and BFS by Rockwell. It is completely different and only handles the primary flight regimes
The shuttle never actually flew on BFS, right?
Never been engaged in flight, but it's always active. It's used for ascent and (i think) landing for monitoring certain parameters up/down hill.
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#2128
by
DansSLK
on 11 Aug, 2011 20:38
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Orginally, PASS was written by IBM and BFS by Rockwell. It is completely different and only handles the primary flight regimes
The shuttle never actually flew on BFS, right?
BFS performs SM functions with PASS in 4 GPC RS GNC
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#2129
by
Naito
on 11 Aug, 2011 20:43
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Which aerosurface on the orbiter is used for the post-MLG touchdown derotation?
The elevons.
Specifically I believe they use the elevon TRIM control to de-rotate, because doing it the other way was too finicky and resulted in the Columbia wheelie on STS-3
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#2130
by
JayP
on 11 Aug, 2011 21:50
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Which aerosurface on the orbiter is used for the post-MLG touchdown derotation?
The elevons.
Specifically I believe they use the elevon TRIM control to de-rotate, because doing it the other way was too finicky and resulted in the Columbia wheelie on STS-3
The elevons don't have trim tabs like a conventional aircraft. They are the only "aerosurfaces" on the wings.
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#2131
by
Specifically-Impulsive
on 12 Aug, 2011 00:23
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Which aerosurface on the orbiter is used for the post-MLG touchdown derotation?
The elevons.
Specifically I believe they use the elevon TRIM control to de-rotate, because doing it the other way was too finicky and resulted in the Columbia wheelie on STS-3
The elevons don't have trim tabs like a conventional aircraft. They are the only "aerosurfaces" on the wings.
However there is a 'trim control' on the rotational hand controller, "beep trim", that could be used to derotate.
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#2132
by
Specifically-Impulsive
on 12 Aug, 2011 00:30
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Apologize in advance if this has been answered. I did some searching and didn't find it.
Is there a comprehensive, detailed history of all shuttle ferry flights out there somewhere? By "detailed" I mean where they stopped to overnight and when.
Thanks,
S-I
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#2133
by
wolfpack
on 12 Aug, 2011 13:44
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Apologize in advance if this has been answered. I did some searching and didn't find it.
Is there a comprehensive, detailed history of all shuttle ferry flights out there somewhere? By "detailed" I mean where they stopped to overnight and when.
Thanks,
S-I
Logbooks for the STA aircraft, maybe? Good luck compiling it, though. I'll bet there were lots of stops, since STA can't fly through weather, can't fly above 10,000 ft and burns jet fuel like crazy. So any precipitation or headwinds would have forced lots of unplanned stops over the years.
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#2134
by
spacecane
on 12 Aug, 2011 16:01
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Two questions today...
1) I remember during the weather uncertainty lead up to STS-135, the weather officer mentioned that no flight through precipitation was a shuttle specific launch constraint. Why can other rockets fly through precip but the shuttle couldn't? Was it that hitting rain at high speed could damage the TPS tiles?
2) Why is the SSME "flame" almost clear and cone shaped while other LH2/LOX engines like the one's on Delta IV have long orange/purple exhaust flames. Is it different exhaust temperature?
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#2135
by
Jim
on 12 Aug, 2011 16:39
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1. Yes, precip would erode the tiles.
2. Delta IV uses an ablative nozzle and that material colors the exhaust.
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#2136
by
Ronsmytheiii
on 12 Aug, 2011 20:39
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1. Yes, precip would erode the tiles.
And to add on to this, as the last flight tile erosion would not have been as big of an issue as there was not a need to turn around. The big issue was energy for landing, as tiles would absorb moisture increasing the weight of the orbiter, and therefore also robbing momentum to get to the runway. Obviously it was felt that the risks were protected, and they launched.
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#2137
by
Danny Dot
on 13 Aug, 2011 14:21
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Orginally, PASS was written by IBM and BFS by Rockwell. It is completely different and only handles the primary flight regimes
The shuttle never actually flew on BFS, right?
BFS was never used.
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#2138
by
alk3997
on 13 Aug, 2011 14:28
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Orginally, PASS was written by IBM and BFS by Rockwell. It is completely different and only handles the primary flight regimes
The shuttle never actually flew on BFS, right?
BFS was never used.
Actually - not quite right.
BFS - Originally designed just for ALT flights then expanded to include OFT (STS-1 through STS-4) and then kept for the rest of the program (I left out a few steps).
BFS was running and active for all launches and landings (as stated above). It had SM functions (including s-band antenna pointing) and until the 2000s contained some ascent displays that provided additional data above what was displayed on the primary displays. This was called "Listen Mode" and did not allow for active control of the vehicle steering functions (GN&C, more accurately). "Engaged Mode" took over full control from the primary computers.
BFS was *never* engaged. But, it was used multiple times to close the payload bay doors after a landing wave-off. This was done with BFS since it was a faster procedural method than using PASS. While the doors moved at the same rate whether PASS or BFS, there were less steps required to let BFS close the doors. The faster the doors closed, the less time was used with our entry cooling capabilities, which were going to be needed again the next day.
A DTO was planned, early in the program, to try BFS after OMS-2. But, no one could justify why that was needed in-flight since all of the similators showed no problems with engaging BFS.
Andy
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#2139
by
Mark Dave
on 14 Aug, 2011 22:13
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