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#1880 by AS-503 on 25 Apr, 2011 18:59
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Thanks for the clarification Jim.
P.S. Are you back to shooting from the hip?
Here is an STS-1 question for you.
I have read that the body flap on Columbia was forced past the allowable operational limits at SRB ignition due to the acoustic over-pressure on STS-1. (no water deluge)
My question is: how close to failure of the actuation mechanism (hydraulics) for the body flap was this over-pressure load?
No control of the body flap on re-entry means LOC/LOV, right?
What kind of margins are built into that "unauthorised" movement for the mechanism that moves/controls the body flap.
Given that surfaces like these are software/computer controlled. If the flap on STS-1 (or any flight) needed to be "recalibrated", does the software now how to extrapolate new values to dynamically (on the fly) recalibrate itself for the duration of the flight until physical "recalibration" could be done in the OPF?
Also in slight relation to the body flap (on re-entry) didn't STS 1 have an issue on re-entry in that the re-entry software had been programmed with upper atmospheric oxygen being di-atomic instead of single molecule resulting in errors with side slip?
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#1881 by Jim on 25 Apr, 2011 19:16
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Thanks for the clarification Jim.
P.S. Are you back to shooting from the hip?
Here is an STS-1 question for you.
Nope and somebody else will have to answer those questions, but yes it would be an LOW/LOC and there were other aerosurfaces that were over stressed.
As for the "unauthorised" movement,
1. was it ever stated that the surfaces didn't return to preflight positions?
2. Most feedback is based on the actual position (actuator stroke length or rotation)and the software would see the "new" position. -
#1882 by alexw on 26 Apr, 2011 06:45
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Jim is apparently feeling loquacious
Is the twang video real time, ie true 1:1?
-Alex -
#1883 by ChrisGebhardt on 26 Apr, 2011 14:07
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Jim is apparently feeling loquacious
Is the twang video real time, ie true 1:1?
-Alex
It's not 1:1. More like 1.5:1 -
#1884 by AS-503 on 26 Apr, 2011 20:30
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Are the hard attach points on the Orbiter for the fuel and oxidiser lines from the ET positioned at (or sufficiently close to) the Orbiter's center of gravity (center of mass)?
Are payloads situated within the payload bay to help define/balance this point (at least for ascent)?
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#1885 by Jim on 26 Apr, 2011 21:14
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Are the hard attach points on the Orbiter for the fuel and oxidiser lines from the ET positioned at (or sufficiently close to) the Orbiter's center of gravity (center of mass)?
Are payloads situated within the payload bay to help define/balance this point (at least for ascent)?
The position of the payloads in the bay is more important for entry and landing. The orbiter/ET attach points are aft of the landing gear, just forward of the elevon hinge line. Which is certainly aft of the orbiter CG. -
#1886 by Ronsmytheiii on 28 Apr, 2011 02:41
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On STS-88, Endeavour had the airlock tunnel adapter installed as well as the External airlock/ODS. Now as I understand it, the previous year she had her internal airlock removed meaning the tunnel adapter was not needed for the ODS. Now on her previous flight, STS-89 she flew in the same condition except with a SpaceHab module attached to the ODS airlock, so the tunnel makes sense for EVA access but on STS-88 there was nothing covering up the ODS EVA hatch. Thinking logically, the best theory I could come up with was the need for more clearance due to the fact that she docked "upside down" to the PMA-2 relative to what is done today. Is that correct?
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#1887 by Jim on 28 Apr, 2011 12:33
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No, it was known early as I stated in MGVT.
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#1888 by Fequalsma on 28 Apr, 2011 18:41
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Orbiter CG is around Xo1120 - Xo1135 depending on the payload mass. P/L bay aft bulkhead is Xo1307, and the Orbiter/ET aft hardpoints are around Xo1317 (The Orbiter nose is around Xo235).
UPDATE - The LO2 and LH2 feedline centers are at Xo1330.5
Are the hard attach points on the Orbiter for the fuel and oxidiser lines from the ET positioned at (or sufficiently close to) the Orbiter's center of gravity (center of mass)? -
#1889 by DMeader on 04 May, 2011 13:26
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Has a Shuttle launch ever been filmed by a camera mounted in one of the overhead windows of the aft flight deck station? Looks like that would be a pretty spectacular view. Searching here I find nothing.
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#1890 by psloss on 04 May, 2011 13:29
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Has a Shuttle launch ever been filmed by a camera mounted in one of the overhead windows of the aft flight deck station? Looks like that would be a pretty spectacular view. Searching here I find nothing.
Couple of times that I can think of (with a video camera) -- STS-93 and STS-102...first one was night-time and for the dawn 102 launch after roll to heads down, it's mostly water. The STS-102 video is around online, I believe.
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#1891 by Space Invaders on 04 May, 2011 13:51
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Is there an estimate of the costs incurred for each day a Shuttle launch is delayed? (including only the "basic costs", i.e., without including any potential repairs).
I once read that delayed launches cost $28 million per day, but this figure seems way too high to me just to keep the Shuttle on the launchpad. -
#1892 by dninness on 04 May, 2011 15:31
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FOD question.
In looking at the LCA replacement photos in the KSC Media Gallery (http://mediaarchive.ksc.nasa.gov/search.cfm?cat=4), I noted that the first few photos of the guys climbing around in the aft of Endeavor were wearing coveralls (not the full blown bunny suits with booties, but at least coveralls), whereas the later photos of the folks doing the R&R of the LCA were in jeans,sneakers(sorry, "trainers"..), etc.
Having worked helicopter maintenance in my early years, I am cognizant of the hazard presented by items that are worn or found in pockets that become dropped items (tools, change, rings, ID badges, etc). I can only imagine that working around the shuttle is 10x more complicated in the event that something were to get loose in the aft of the orbiter and do the old "ping-ding-boink-rattle-rattle-rattle" trip to the lowest point it can reach. Imagine that IPR: "Joe's wedding ring found on #3 engine heatshield dome. His wife will be happy."
My question is: what precautions are in place at the pad, and especially when working inside the orbiter, for FOD prevention?
If you're doing maintenance in essentially "street clothes" are there provisions for removing FOD hazards from pockets, fingers, etc? In one photo, one of the workers was definitely wearing a wedding ring (a no-no where I worked), and in another a wristwatch, so it *appears* (to me, the uninitiated outside observer) that there are very little FOD prevention measures in effect.
What about things like FOD stuck in the tread of your sneakers, for example?
Thanks in advance!
Darin -
#1893 by JayP on 04 May, 2011 15:33
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Is there an estimate of the costs incurred for each day a Shuttle launch is delayed? (including only the "basic costs", i.e., without including any potential repairs).
I once read that delayed launches cost $28 million per day, but this figure seems way too high to me just to keep the Shuttle on the launchpad.
The $28 million is probably the cost of a scrubed attempt, not a per day cost. The cost of a shuttle sitting on the pad depends on how you want to calculte it. Assuming no actual material cost (nothing is being used up) then you are just talking about the saleries of the people involved who are getting paid anyways. Eventualy, if it sits out there long enough, some material costs will come into play to recharge batteries if nothing else. -
#1894 by ChrisGebhardt on 04 May, 2011 15:39
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Is there an estimate of the costs incurred for each day a Shuttle launch is delayed? (including only the "basic costs", i.e., without including any potential repairs).
I once read that delayed launches cost $28 million per day, but this figure seems way too high to me just to keep the Shuttle on the launchpad.
The $28 million is probably the cost of a scrubed attempt, not a per day cost. The cost of a shuttle sitting on the pad depends on how you want to calculte it. Assuming no actual material cost (nothing is being used up) then you are just talking about the saleries of the people involved who are getting paid anyways. Eventualy, if it sits out there long enough, some material costs will come into play to recharge batteries if nothing else.
But where does the $28 million come from? -
#1895 by Jim on 04 May, 2011 15:55
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FOD question.
1. In looking at the LCA replacement photos in the KSC Media Gallery (http://mediaarchive.ksc.nasa.gov/search.cfm?cat=4), I noted that the first few photos of the guys climbing around in the aft of Endeavor were wearing coveralls (not the full blown bunny suits with booties, but at least coveralls), whereas the later photos of the folks doing the R&R of the LCA were in jeans,sneakers(sorry, "trainers"..), etc.
2. My question is: what precautions are in place at the pad, and especially when working inside the orbiter, for FOD prevention?
3. If you're doing maintenance in essentially "street clothes" are there provisions for removing FOD hazards from pockets, fingers, etc? In one photo, one of the workers was definitely wearing a wedding ring (a no-no where I worked), and in another a wristwatch, so it *appears* (to me, the uninitiated outside observer) that there are very little FOD prevention measures in effect.
4. What about things like FOD stuck in the tread of your sneakers, for example?
Thanks in advance!
Darin
1. Bunny suits are only required for payload bay or crew module access. The rest of the orbiter is not a "clean" area
2. same processes
3. watches are allowed but either have to be taped or don't come completely apart.
4. Tacky mats are used at the entrance. -
#1896 by JayP on 04 May, 2011 16:36
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4. What about things like FOD stuck in the tread of your sneakers, for example?
4. Tacky mats are used at the entrance.
And if you look closely in those photos, everyone who is actually in the aft is wearing covers over their shoes. -
#1897 by dninness on 04 May, 2011 16:43
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And if you look closely in those photos, everyone who is actually in the aft is wearing covers over their shoes.
Actually, not: http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=52363
Thats what sort of prompted the question.
It just seemed odd to me, especially considering, say, the issue with the emergency air pack that bounced around the aft (was that STS-133? I forget) that there was the potential for change, keys, "very small rocks," etc to wind up in the nether regions of the Shuttle.
Thanks for the info, guys! Very informative. -
#1898 by JayP on 04 May, 2011 17:22
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And if you look closely in those photos, everyone who is actually in the aft is wearing covers over their shoes.
Actually, not: http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=52363
Actually, yes. The covers have a red sole with a white upper that covers about the bottom half of the shoes sides and the front half of the tongue area. You can see it better in the following picture of the same 2 people.
http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=52362
I have also attached some blowups where I have outlined the covers.
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#1899 by dninness on 04 May, 2011 18:31
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Oops, totally obvious now! Thanks!
