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#180
by
darkenfast
on 06 Jul, 2006 09:04
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Ahh...certainly more dignified than my guess! Thanks for sharing that.
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#181
by
kneecaps
on 06 Jul, 2006 10:41
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In the timelines they refer to a PRIORITY PWRUP GRP B B
(ORB PKT, PRIOR PWRDN)
I know that the section in brackets refers to a checklist however I don't know what checklist the ORB PKT is , any ideas?
A quickie for somebody in the know!
Thanks
Pete
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#182
by
British NASA
on 06 Jul, 2006 13:27
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Robert A.M. Stephens - 6/7/2006 1:48 AM
Question: what did John Young say right after the STS-1 landing about the STS?
Answer:
He walked hurriedly around the orbiter for an initial looksee, as Crippen was also egressing, then up to the mic, and said;
"Hail, Columbia."
Then he turned slightly, pointing at the orbiter, still looking at the attending crowd (an me) and said, "That is one incredible flying machine."
Quite a moment and my first assignment for the agency for documenting STS and other space related endeavors, then and now. I always remembered that line since it was so profound and so out of character for the otherwise very cool John Young, a very gutsy man indeed. I documented STS-1 for launch and then out to EAFB for the landing.
Robert
That's awesome!
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#183
by
Jim
on 06 Jul, 2006 15:37
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kneecaps - 6/7/2006 6:28 AM
In the timelines they refer to a PRIORITY PWRUP GRP B B
(ORB PKT, PRIOR PWRDN)
I know that the section in brackets refers to a checklist however I don't know what checklist the ORB PKT is , any ideas?
A quickie for somebody in the know!
Thanks
Pete
Orbiter Pocket Checklist
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#184
by
mkirk
on 06 Jul, 2006 21:59
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Jim - 6/7/2006 10:24 AM
kneecaps - 6/7/2006 6:28 AM
In the timelines they refer to a PRIORITY PWRUP GRP B B
(ORB PKT, PRIOR PWRDN)
I know that the section in brackets refers to a checklist however I don't know what checklist the ORB PKT is , any ideas?
A quickie for somebody in the know!
Thanks
Pete
Orbiter Pocket Checklist
The Pocket Checklists are primarily for “Non Nominal Procedures” that require time critical responses. Time critical is defined as procedures requiring a response in 5 minutes or less. There are three Pocket Checklists called Ascent, Entry and Orbit.
The Group B Priority Powerdown is contained in the Orbit Pocket Checklists however the use of the powerdown in this case is a routine procedure and not a reaction to a malfunction.
The lettered powerdowns (A, B and C) are designed for mission specific operations while the numbered powerdowns (1,2,3 etc.) are for contingencies. Each powerdown procedure is designed to either decrease the electrical or thermal load by shutting down systems in an orderly and efficient manner.
In this particular case the Group B Powerdown helps reduce the load on the fuel cells and in turn the amount of cryogenics (oxygen & hydrogen) consumed so that the mission can potentially be extended to support the 3rd EVA. Group B reduces electrical load by turning off none essential lighting, flight displays, CRTs/MFD (multifunction displays), heaters, MDMs (multiplexer demultiplexers) and other non essential equipment.
Mark Kirkman
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#185
by
Chris Bergin
on 07 Jul, 2006 05:34
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Not sure what this was doing as a new thread in the video section...anyway, moved into the right place:
Zoomer30 - 7/7/2006 4:52 AM
A few times in Shuttle history at the moment of SRB ignition you will see a BIG cloud form behind the shuttle stack, as tall as the ET. Seems like a shockwave cloud. Anyone know of a flgiht where this happened. I think it must happen when the temp and dewpoint are very close together (ie, very humid day)
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#186
by
GLS
on 09 Jul, 2006 15:54
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The shock wave from the SRB ignition compresses the air so much that it can't *hold* all the moisture and it becames visible. That also happens as the vehicle passes by layers of humid air (and clouds).
Recently, STS-104 had alot of this... on SRB ignition, as it clears the tower and until about 50 sec or so... A few others are STS-96, STS-32R, STS-82, STS-86, STS-24, STS-25, etc....
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#187
by
shuttlefan
on 09 Jul, 2006 17:08
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Can someone tell me: On what Shuttle flight prior to Challenger/51-L, did they experience the worst o-ring erosion on an SRB field joint?
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#188
by
DwightM
on 09 Jul, 2006 18:15
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This isn't for certain, but I seem to remember that 51C (Discovery) a year prior had some nasty erosion.
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#189
by
Zoomer30
on 09 Jul, 2006 21:33
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I think this is an issue with camaras that use CCDs to capture the image. My Canon A75 does the same thing if I point it at the sun. On the LCD screen you will see to "beams" coming out from the sun image. I think part of it is that CCDs have issues with very bright things on somewhat darker backgrounds. The CCD has "cells" on it that catch the light, if a cell get to much light it can spill over.
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#190
by
Zoomer30
on 09 Jul, 2006 21:36
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I think historcally the worst O-Ring damage that had been seen before 51-L was on STS 2. That was a casue for some of the "disaggrements" in the telecon that they had the night before the launch. The managers pointed out that STS2 had the worst damage they had seen and the air temp at launch was almost 90F.
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#191
by
Naraht
on 09 Jul, 2006 22:06
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shuttlefan - 9/7/2006 5:55 PM
Can someone tell me: On what Shuttle flight prior to Challenger/51-L, did they experience the worst o-ring erosion on an SRB field joint?
I've taken a browse through Diane Vaughan's book on Challenger, and I think that STS-2 would have had the most erosion of an O-ring on an SRB field joint. (0.053"). 51-C (the launch at very low temperature) had some erosion, but it was really the blow-by that was of concern on that flight. 51-B had the most serious erosion but that was on a nozzle joint rather than a field joint.
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#192
by
ruthsarian
on 11 Jul, 2006 15:43
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Just another crazy "what if".
If there was a serious problem with the SRBs immediately after liftoff is it at all possible to do an SRB sep at low altitude and would the SSME have enough thrust to keep the shuttle up long enough to return safely? I know the SSMEs provide a low percentage of the total thrust used to get the shuttle up (23% is it?) but the SRB weight is more than half of the total stack's weight, so would the SSMEs be enough without the SRB weight? This is ignoring the fact that the SRBs would need to be destroyed immediately to keep them from crashing into populated areas.
The RSS units on the SRBs and ET are connected so if one receives an arm/fire signal it's passed to all three units. Is this a physical connection? Meaning if the SRBs are separated and only one receives the signal, will only the one SRB destruct or does it pass that signal on? And is the arm/fire signal for the RSS units the same signal for all three or can the RSO target which receives the signal? So in the event of the senario given above, could the RSO destroy the SRBs without triggering the ET RSS unit?
How much education/discussion is there with the astronauts about RSSs, how the RSO makes his/her decision, and what the worst-case scenarios are? Is it something that you just don't really talk about?
I don't mean to be morbid if this comes off as such. It's just that these are aspects of the shuttle you never hear much about.
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#193
by
Jim
on 11 Jul, 2006 15:52
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The SRB/ET joint only allows disengagement one way: ET up -SRB down. The SRB plume would burn the shuttle. Not enough thrust. I think the ET RSS was removed (see other threads). The SRB are cross linked and independent. One command does all
The Astronauts are aware of the system and how the decision is made. Of course they know the worst-case scenario (only one): the shuttle is sent the destruct command. And yes, it something that you just don't really talk about
One last point for every one. RSO no longer exists, it is the MFCO (missile flight control officer)
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#194
by
NASA_Twix_JSC
on 11 Jul, 2006 15:58
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If, pretend, there was such a seperation, because they are still going at full thrust, they wouldn't happily drop away, they'd go forward and in various uncontrolled directions. Most likely roasting those on board as they destroy the orbiter and tank. No option.
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#195
by
Gary
on 11 Jul, 2006 16:44
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Jim - 11/7/2006 4:39 PM
The SRB/ET joint only allows disengagement one way: ET up -SRB down. The SRB plume would burn the shuttle. Not enough thrust. I think the ET RSS was removed (see other threads). The SRB are cross linked and independent. One command does all
The Astronauts are aware of the system and how the decision is made. Of course they know the worst-case scenario (only one): the shuttle is sent the destruct command. And yes, it something that you just don't really talk about
One last point for every one. RSO no longer exists, it is the MFCO (missile flight control officer)
There is quite an in depth explanation of the Range Saftey System both pre and post Challenger in Mike Mullanes 'Riding Rockets' book.
In there he does mention that the ordanance package was removed from the ET post Challenger.
Thanks for a fascinating thread and I know this is repeating what others have said but this really is the most informative website for any space-related so thanks to everyone for that.
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#196
by
elmarko
on 17 Jul, 2006 15:46
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From the Entry Checklist:
HATCH OPENING (ELS)
Before hatch opening:
Tabs/Visor - CL
Green Apple - PULL
Firstly, what is ELS? And secondly, what the heck is the Green Apple?
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#197
by
Jim
on 17 Jul, 2006 15:50
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You need to expand the portion of the checklist
Green apple is the emergency O2 valve.
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#198
by
elmarko
on 17 Jul, 2006 15:53
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Aha, thanks. Do you have any idea why it is so named? It's shape or appearance?
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#199
by
Jim
on 17 Jul, 2006 15:56
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elmarko - 17/7/2006 11:40 AM
Aha, thanks. Do you have any idea why it is so named? It's shape or appearance?
Both. It is an Air Force term
