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#960
by
ginahoy
on 16 Feb, 2010 05:33
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That has been done ever since they started wearing the suits. The reason is that the suits are preasurized with pure oxygen and they are open loop (gas is vented out of the suit into the cabin instead of being rerouted back to the ECS) that leads to the concentration of O2 in the cabin building up more the longer they are in use, which is a fire hazard (remeber Apollo1). That is also why they don't close the visors at all durring entry after the preasure test.
I guess they can close those visors real fast in a depress event.
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#961
by
The-Hammer
on 16 Feb, 2010 06:04
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That has been done ever since they started wearing the suits. The reason is that the suits are preasurized with pure oxygen and they are open loop (gas is vented out of the suit into the cabin instead of being rerouted back to the ECS) that leads to the concentration of O2 in the cabin building up more the longer they are in use, which is a fire hazard (remeber Apollo1). That is also why they don't close the visors at all durring entry after the preasure test.
I guess they can close those visors real fast in a depress event.
Actually, as I recall, that was one of the things mentioned by one of the Columbia reports. The cabin depressed too fast and everyone lost consciousness before they had a chance to close and lock visors.
The report in question was one of the more recent ones. It was posted in the historical section, I'll try to find it.
EDIT: I believe that this is the report in question.
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#962
by
butters
on 16 Feb, 2010 07:24
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But the ACES suits, even with visors closed, would not have been sufficient to protect the crew from the dynamic pressure at which Columbia disintegrated. The suits disintegrated themselves.
I know they can do Mach 3.2 at 80,000 ft, but I don't know exactly how much more dynamic pressure they can handle. Loss of cabin pressure is one thing, but ACES can't help with severe loss of vehicle structural integrity through much of the reentry phase.
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#963
by
steveS
on 16 Feb, 2010 08:42
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Now that Node 3 and cupola are installed in the ISS, will there be significant changes for future shuttle docking procedures from STS-131 onwards?
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#964
by
Jorge
on 16 Feb, 2010 14:05
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Now that Node 3 and cupola are installed in the ISS, will there be significant changes for future shuttle docking procedures from STS-131 onwards?
No.
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#965
by
DaveS
on 16 Feb, 2010 14:27
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Any shuttle DPS experts here? Then this question is for them: What is the font used for the MEDS DPS displays?
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#966
by
Gwilbor
on 16 Feb, 2010 14:57
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Seeing the launch footage of the shuttle, I was trying to understand what happens around external tank separation...
1. It seems to see some RCS firing after 10 seconds from zero-thrust (well before separation), am I correct? Which RCS?
2. The -Z thrust starts exactly at sep or before?
3. How many seconds after sep starts the +X thrust?
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#967
by
mkirk
on 16 Feb, 2010 19:00
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Seeing the launch footage of the shuttle, I was trying to understand what happens around external tank separation...
1. It seems to see some RCS firing after 10 seconds from zero-thrust (well before separation), am I correct? Which RCS?
2. The -Z thrust starts exactly at sep or before?
3. How many seconds after sep starts the +X thrust?
1. No (if you are referring to the 10 second period prior to MECO). What you are seeing are plasma dynamics and SSME plume contraction during throttle down and fine count.
2. -Z translation occurs after the SEP Command is issued, not before. However, RCS firings can occur during the mated coast phase for attitude/rate control. These firings are managed by the "Trans Dap" (transition digital auto pilot).
3. +X is a manual input by the Commander which occurs 2 seconds after the general purpose computers transition to OPS 104 (this transition occurs when the -Z achieves a delta V of 4 feet per second).
Mark Kirkman
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#968
by
Gwilbor
on 16 Feb, 2010 19:52
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1. No (if you are referring to the 10 second period prior to MECO).
No, it's a plume that occurs roughly 10 seconds after MECO. Maybe is the attitude control you mentioned on answer #2. For example at 9:30 in this video:
Or at 9:55 here:
2. -Z translation occurs after the SEP Command is issued, not before. However, RCS firings can occur during the mated coast phase for attitude/rate control. These firings are managed by the "Trans Dap" (transition digital auto pilot).
3. +X is a manual input by the Commander which occurs 2 seconds after the general purpose computers transition to OPS 104 (this transition occurs when the -Z achieves a delta V of 4 feet per second).
Mark Kirkman
Thank you!
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#969
by
usn_skwerl
on 16 Feb, 2010 22:24
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Forgive me if it's in the wrong place, but on the NASA TV map, what is the yellow line that goes roughly north-south?
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#970
by
ddunham
on 17 Feb, 2010 16:48
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Forgive me if it's in the wrong place, but on the NASA TV map, what is the yellow line that goes roughly north-south?
It's hard to see because of the map projection, but that line actually is basically circular on the earth, and shows the extent of coverage of one of the TDRS communication satellites at the altitude of the shuttle. The green line is the extent of the other major one.
The satellites are shown on the graphic as well, with color coding corresponding to the coverage lines.
--
Darren
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#971
by
usn_skwerl
on 18 Feb, 2010 20:09
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OH! duh! Thank you so much. I can't believe I didn't think about that. sheesh.
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#972
by
GoForTLI
on 21 Feb, 2010 00:38
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EVA crew on STS-130 apparently got their metabolic rates up when dealing with the Cupola MLI, and they were instructed to hang out for a little while. What's the tradeoff when planning EVAs for jettison vs. roll up the MLI and bring it back inside? I seem to recall on a previous mission we jettisoned MLI or at least some kind of thermal cover.
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#973
by
steveS
on 21 Feb, 2010 03:09
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STS -132 is named as ULF4 (Utilities and Logistics) while STS-131 is 19A (Assembly)? STS-132 carries MRM1 to be installed in the ISS while STS-132 carries MPLM Leonardo. I thought STS-132 must be an assembly flight while STS-131 must be a Utilities and Logistics flight. Any comments on this naming?
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#974
by
Jorge
on 21 Feb, 2010 04:14
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STS -132 is named as ULF4 (Utilities and Logistics) while STS-131 is 19A (Assembly)? STS-132 carries MRM1 to be installed in the ISS while STS-132 carries MPLM Leonardo. I thought STS-132 must be an assembly flight while STS-131 must be a Utilities and Logistics flight. Any comments on this naming?
Historical artifact.
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#975
by
steveS
on 21 Feb, 2010 04:45
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In that case, why cant they rename the missions again? I mean with A's and ULF's
STS -132 is named as ULF4 (Utilities and Logistics) while STS-131 is 19A (Assembly)? STS-132 carries MRM1 to be installed in the ISS while STS-132 carries MPLM Leonardo. I thought STS-132 must be an assembly flight while STS-131 must be a Utilities and Logistics flight. Any comments on this naming?
Historical artifact.
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#976
by
Jorge
on 21 Feb, 2010 05:09
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In that case, why cant they rename the missions again? I mean with A's and ULF's
STS -132 is named as ULF4 (Utilities and Logistics) while STS-131 is 19A (Assembly)? STS-132 carries MRM1 to be installed in the ISS while STS-132 carries MPLM Leonardo. I thought STS-132 must be an assembly flight while STS-131 must be a Utilities and Logistics flight. Any comments on this naming?
Historical artifact.
They won't. There is too much internal documentation with the current mission designations. It would result in confusion. Keeping the names provides continuity in the documentation trail, even though the mission content has rendered the names obsolete.
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#977
by
Jim
on 21 Feb, 2010 09:58
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STS -132 is named as ULF4 (Utilities and Logistics) while STS-131 is 19A (Assembly)? STS-132 carries MRM1 to be installed in the ISS while STS-132 carries MPLM Leonardo. I thought STS-132 must be an assembly flight while STS-131 must be a Utilities and Logistics flight. Any comments on this naming?
It is Utilization and Logistics.
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#978
by
theandrew
on 21 Feb, 2010 22:37
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I have another nasa tv question. When they are covering the shuttle launch/landing, they generally show a screen showing the earth, and the current orbit of the ISS and shuttle.
On this screen, there several circles/shapes with letters inside (SAA,TCSS...). What are those shapes? Also, there are some other indications on the screen, and some other satellites. Any descriptions?
Thanks!
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#979
by
Jim
on 21 Feb, 2010 23:27
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I have another nasa tv question. When they are covering the shuttle launch/landing, they generally show a screen showing the earth, and the current orbit of the ISS and shuttle.
On this screen, there several circles/shapes with letters inside (SAA,TCSS...). What are those shapes? Also, there are some other indications on the screen, and some other satellites. Any descriptions?
Search the shuttle Q&A thread