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#1020
by
thomasafb
on 24 May, 2008 12:36
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mkirk - 24/5/2008 7:56 AM
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
The Pocket Checklists lead me back to where i came from...they have a Power Down section but that ends with a reference to EXPEDITED PWRDN (ENT, POST LDG) at 5-2 ;-)
As for the AESP, it seems to be unavailable on L2, at least a search did not bring up anything apart from further references to it...must be a great piece of work.
Nevertheless, thanks for pointing me in the right direction.
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#1021
by
mkirk
on 24 May, 2008 18:22
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thomasafb - 24/5/2008 7:36 AM
The Pocket Checklists lead me back to where i came from...they have a Power Down section but that ends with a reference to EXPEDITED PWRDN (ENT, POST LDG) at 5-2 ;-)
As for the AESP, it seems to be unavailable on L2, at least a search did not bring up anything apart from further references to it...must be a great piece of work.
Nevertheless, thanks for pointing me in the right direction.
Here is the Cue Card.
I found a relatively recent copy of the AESP in the L2 section and bumped it into the L2 STS-124 Special Section for you.
Mark Kirkman
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#1022
by
thomasafb
on 24 May, 2008 20:52
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A million thanks. I have no idea why it did not show up in my search.
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#1023
by
elmarko
on 26 May, 2008 17:51
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I've been reading up about abort modes seen as they've come up in the past few pages. Can someone please tell me why on a Bailout the crew has to invoke an ATO abort with the rotary switch before leaving the orbiter, as per the Mode 8 cue card?
I may have other questions too, aborts are fascinating to read about.
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#1024
by
mkirk
on 26 May, 2008 18:18
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I've been reading up about abort modes seen as they've come up in the past few pages. Can someone please tell me why on a Bailout the crew has to invoke an ATO abort with the rotary switch before leaving the orbiter, as per the Mode 8 cue card?
I may have other questions too, aborts are fascinating to read about.
Selecting ATO is simply a means of telling the guidance system to maintain attitude in support of the BAILOUT. The BAILOUT procedure is designed for use in "controlled flight".
ATO is used because ATO aborts do not have an entry function within the flight software so it was available for use in this capacity.
Mark Kirkman
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#1025
by
elmarko
on 26 May, 2008 22:03
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Thanks Mark.
One more if I may. I was reading the old Contingency Abort training manual from January 1986, and it talks about ditching the orbiter. Obviously, the events of that month changed things somewhat, but is a ditch procedure still trained for and available if there was some problem that made a bailout impossible? IE, injury, systems failure, for example?
I realise people don't like to talk about aborts, I personally have never been that bothered about it. I think it's good to talk about all these wonderful and possibly life-saving procedures.
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#1026
by
DaveS
on 27 May, 2008 20:13
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Can someone please tell me if the Orbiter Weather Protection system panels coverage is correct on this 3D model?
I'm mostly interested in comments of the upper wing cover panels that covers the RCC WLE panels.
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#1027
by
mkirk
on 28 May, 2008 00:08
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Thanks Mark.
One more if I may. I was reading the old Contingency Abort training manual from January 1986, and it talks about ditching the orbiter. Obviously, the events of that month changed things somewhat, but is a ditch procedure still trained for and available if there was some problem that made a bailout impossible? IE, injury, systems failure, for example?
Not really.
The current philosophy is that if the orbiter cannot make it to the runway (i.e. too little or too much energy) then the crew will BAILOUT. This includes systems problems that would make a safe runway landing impossible – such as inability to deploy the landing gear (assuming you have that information ahead of time).
As for problems with the escape system; it is highly unlikely that you would know ahead of time that the hatch won’t blow, or the pole won’t extend. In the event you find this out – as you are descending thru 50-30 thousand feet – there is little that can be done, from a piloting prospective, to minimize the likely catastrophic nature of ditching an orbiter.
General consensus is that even if you were to hit the water with a clean orbiter (i.e. no gear extended) in a wings level, slightly nose high attitude (or no pitch at all), the orbiter is expected to break up. A heavy payload would likely go thru the forward bulkhead and the numerous propellant tanks within the orbiter are not going to stay in their mounts.
Mark Kirkman
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#1028
by
brahmanknight
on 28 May, 2008 16:45
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At what point are the Fuel Cells turned "on" for flight operations?
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#1029
by
mkirk
on 28 May, 2008 16:52
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At what point are the Fuel Cells turned "on" for flight operations?
Fuel Cell activation occurs at T-9 hours 50 minutes, however, all loads are shared with the ground support equipment until around T-50 seconds when ground power is removed and the vehicle is operating entirely on the Fuel Cells.
Mark Kirkman
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#1030
by
jadedflanker
on 30 May, 2008 03:27
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After looking at the hi-res Kibo pics on L2, I had a question about the payload bay. How is pressure equalization handled? Are the doors hermetically sealed, and is pressure regulated by a valve somewhere? Or is there space between the hinges/ centerline where air can enter? I would imagine its valve operated, but I haven't seen anything regarding a pressure relief valve
Thanks
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#1031
by
mkirk
on 30 May, 2008 03:57
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After looking at the hi-res Kibo pics on L2, I had a question about the payload bay. How is pressure equalization handled? Are the doors hermetically sealed, and is pressure regulated by a valve somewhere? Or is there space between the hinges/ centerline where air can enter? I would imagine its valve operated, but I haven't seen anything regarding a pressure relief valve
Thanks
The active vent system - thru operation of the orbiter vent doors (specifically doors 3, 5, and 6) - controlls the pressure in the payload bay.
You can find more info on the payload bay doors and the active vent system at this link for the Mechanical System's chapter of the SCOM.
http://www.shuttlepresskit.com/scom/217.pdfMark Kirkman
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#1032
by
Jim
on 30 May, 2008 12:21
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After looking at the hi-res Kibo pics on L2, I had a question about the payload bay. How is pressure equalization handled? Are the doors hermetically sealed, and is pressure regulated by a valve somewhere? Or is there space between the hinges/ centerline where air can enter? I would imagine its valve operated, but I haven't seen anything regarding a pressure relief valve
Thanks
The payload bay can not handle the pressure differential. The hinges/ centerline are far from being "seals". As Mark explained, there are vents to let air out during ascent and in during descent
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#1033
by
brahmanknight
on 30 May, 2008 14:27
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I know that if the 17 inch disconnect doors don't close on the belly of the shuttle, that a contingency spacewalk can be performed to close them. How would the spacewalkers translate on the heat shield? I guess they could use the OBSS boom now a days, but how would they have done it before STS 114?
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#1034
by
maxx
on 31 May, 2008 17:49
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Anyone know why the Shuttle hatch opens to the outside?
I always thought that the doors hinges are located on the side where there is the most pressure. My impression is that the pressure helps the seal to be airtight as it compresses the joints...
Or is it to help in case of emergency like in public venue to avoid stampedes or slowing down the evacuation?
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#1035
by
Jim
on 31 May, 2008 17:53
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Anyone know why the Shuttle hatch opens to the outside?
I always thought that the doors hinges are located on the side where there is the most pressure. My impression is that the pressure helps the seal to be airtight as it compresses the joints...
Or is it to help in case of emergency like in public venue to avoid stampedes or slowing down the evacuation?
It was a lesson from Apollo 1. The fire raised the internal pressure of the spacecraft, sealing the crew inside
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#1036
by
maxx
on 31 May, 2008 17:54
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thank for your quick reply
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#1037
by
Jorge
on 31 May, 2008 18:38
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I know that if the 17 inch disconnect doors don't close on the belly of the shuttle, that a contingency spacewalk can be performed to close them. How would the spacewalkers translate on the heat shield? I guess they could use the OBSS boom now a days, but how would they have done it before STS 114?
The procedure was to put dirty clothes or other light articles in a stowage bag and tie that to the end of an EVA safety tether. The EVA crewmember would have translated along the payload bay sill to the aft bulkhead and attempt to "bolo" the bag into the gap between the elevon and the aft compartment, tie off the safety tether onto the sill, then attach his own safety tether to the now-secured tether, translate down the safety tether, flip himself over the side of the elevon and re-secure his safety tether to the neck of the bag.
They would not have attempted translation on the TPS itself. The gap between the elevons and the aft compartment is close enough to the ET umbilical doors that they could reach the door frame from there and pull themselves along until they could reach the latches.
Most EVA crewmembers I've discussed this technique with were skeptical it would work, but felt it was a decent starting point and was better than having no procedure at all.
In the pre-SAFER days, EVA rescue training in the SES consisted of several different scenarios and the last, most difficult, run was the case where the EVA crewmember becomes untethered on the underside of the vehicle while attempting this procedure. It's a lot easier if the RMS is available to view the EVA crewmember using the wrist camera. The RMS wasn't carried on all flights pre-114; on the flights without it, the stranded crewmember would have to "GCA" the CDR to translate the orbiter until he could reach structure.
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#1038
by
mkirk
on 31 May, 2008 19:30
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The procedure was to put dirty clothes or other light articles in a stowage bag and tie that to the end of an EVA safety tether. The EVA crewmember would have translated along the payload bay sill to the aft bulkhead and attempt to "bolo" the bag into the gap between the elevon and the aft compartment, tie off the safety tether onto the sill, then attach his own safety tether to the now-secured tether, translate down the safety tether, flip himself over the side of the elevon and re-secure his safety tether to the neck of the bag.
They would not have attempted translation on the TPS itself. The gap between the elevons and the aft compartment is close enough to the ET umbilical doors that they could reach the door frame from there and pull themselves along until they could reach the latches.
Most EVA crewmembers I've discussed this technique with were skeptical it would work, but felt it was a decent starting point and was better than having no procedure at all.
In the pre-SAFER days, EVA rescue training in the SES consisted of several different scenarios and the last, most difficult, run was the case where the EVA crewmember becomes untethered on the underside of the vehicle while attempting this procedure. It's a lot easier if the RMS is available to view the EVA crewmember using the wrist camera. The RMS wasn't carried on all flights pre-114; on the flights without it, the stranded crewmember would have to "GCA" the CDR to translate the orbiter until he could reach structure.
I took the class - really just a briefing in Building 9 - and we spent most of our time rolling our eyes with some guarded laughter thrown in. Nobody thought much of the idea and of course the real hope is that it would never need to be done.
Mark Kirkman
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#1039
by
michaellefebvre
on 31 May, 2008 22:16
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I just watched a shuttle launch and am puzzled about something.
When the external tank is droped it appears that the shuttles main engines continue to run.
I would assume that the shuttle still need velocity to orbit.
If it were to cut engines at the same time as it drops the tank, it would fall out of orbit like the tank does.
My question is, where does the fuel for the engines come from if
it has droped the external tank?
thks