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#640
by
elmarko
on 21 Sep, 2009 19:32
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How long does that take, though? Would there be a call for some sort of covering device?
Not that matters in this late stage in the program, of course, but was it ever a concern in the past before they realised it wasn't a big deal?
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#641
by
psloss
on 21 Sep, 2009 19:38
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There's no concern of an Orbiter getting rained on while on the SLF/at the MDD. STS-117/Atlantis got a pretty good soaking after her return to KSC on the SCA. They simply dried out her blankets and tiles once she was back in OPF-1.
Thanks for clarifying. Bigger issue to have steady rain -- like we're getting in Atlanta the last few days -- out at Dryden. At KSC, they can demate and tow her into the OPF to get out of any rain. At Dryden, there's at least one case (STS-98) where rain at Dryden soaked some of the tiles enough that it took extra time to "bake" the moisture out with heat lamps when Atlantis got back to Florida. And the rain there keeps the ferry from getting started, which increases the time outdoors.
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#642
by
ChrisGebhardt
on 21 Sep, 2009 19:47
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1) How long does that take, though?
2) Would there be a call for some sort of covering device?
3) Not that matters in this late stage in the program, of course, but was it ever a concern in the past before they realised it wasn't a big deal?
1) Depends on how much water is absorbed.
2) Why would there need to be a covering device when it's no problem if the vehicle gets rained on while at Dryden/on the SLF/at the MDD.
3) No.
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#643
by
fcmadrid
on 21 Sep, 2009 20:25
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Hello!
I'd like to know what are temperatures on that altitude the space shuttle fly?
Thanks
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#644
by
ChrisGebhardt
on 21 Sep, 2009 20:55
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Hello!
I'd like to know what are temperatures on that altitude the space shuttle fly?
Thanks
While on orbit, the Shuttle's exterior temperature can fluctuate between 250° F and -250° F.
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#645
by
elmarko
on 21 Sep, 2009 22:17
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2) Why would there need to be a covering device when it's no problem if the vehicle gets rained on while at Dryden/on the SLF/at the MDD.
I was trying to determine how much of a "non problem" it was - like, how much time it takes to dry out the blankets and tiles vs the cost and effort of covering everything.
Surely there'd be a breakpoint where you decide "Yeah, actually it is worth it..."
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#646
by
psloss
on 21 Sep, 2009 22:27
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Surely there'd be a breakpoint where you decide "Yeah, actually it is worth it..."
Maybe, but it would probably be IF the landing sites were in different climates. As noted, the orbiter is only going to be exposed at the SLF for probably a couple of shifts. Dryden/Edwards is in the middle of a desert -- they generally don't get a lot of rain, and the humidity there is often in the teens. (It's as dry there as it is muggy in Florida in the summer.)
Even in the extreme case (after STS-98), I'd guess that the processing crews learned from the delay to the subsequent flow (for STS-104) and were it to happen again would be able to dry out the TPS without extending an OPF stay.
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#647
by
Hobbs
on 22 Sep, 2009 16:36
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This ought to be fairly well known but I cant seem to find any info anywhere:
How much do the expendables cost on the shuttle per launch, im talking about the cryo's, ET, srb propellant, tyres etc.
Come to think of it, is there a document covering these somewhere (a budget breakdown or such)?
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#648
by
ginahoy
on 22 Sep, 2009 22:10
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During STS-128's approach to Edwards, I recall Rob Navias commented that the twin sonic booms herald the shuttle's approach as it passes through the sound barrier.
I always thought the sonic shock wave is continuous throughout supersonic flight, not just at the mach 1 transition. I guess it's not surprising for a non-technical person to get this wrong, but in the STS-127 crew presentation airing today on NTV, Chris Cassidy made the following comment during the landing replay "...as we come through mach 1, if you've been there, you can hear the two sonic booms."
Now I'm wondering... do I have it wrong?
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#649
by
MKremer
on 22 Sep, 2009 22:21
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2) Why would there need to be a covering device when it's no problem if the vehicle gets rained on while at Dryden/on the SLF/at the MDD.
I was trying to determine how much of a "non problem" it was - like, how much time it takes to dry out the blankets and tiles vs the cost and effort of covering everything.
Surely there'd be a breakpoint where you decide "Yeah, actually it is worth it..."
I think it's probably been determined that the chance of rain (and quantity) around that area at Edwards is low enough that immediately covering the orbiter isn't necessary. (not to say there's an up-to-date quantity of very large sheets in storage there somewhere just in case the unexpected occurs)
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#650
by
Jim
on 23 Sep, 2009 00:55
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During STS-128's approach to Edwards, I recall Rob Navias commented that the twin sonic booms herald the shuttle's approach as it passes through the sound barrier.
I always thought the sonic shock wave is continuous throughout supersonic flight, not just at the mach 1 transition. I guess it's not surprising for a non-technical person to get this wrong, but in the STS-127 crew presentation airing today on NTV, Chris Cassidy made the following comment during the landing replay "...as we come through mach 1, if you've been there, you can hear the two sonic booms."
Now I'm wondering... do I have it wrong?
It is continuous
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#651
by
usn_skwerl
on 23 Sep, 2009 03:26
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Yes, ginahoy, it's continuous, but some of us don't like to give a full explanation. You'd hear it from once the orbiter got into some traces of the atmosphere, at mach 20+, all the way until the point it drops under mach 1. The pressure wave/cone spreads out to roughly 60 miles or so in most directions, aside from the front.
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#652
by
Antares
on 23 Sep, 2009 04:28
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You hear a sonic boom when the shock wave passes over your ears, or the microphone. Not when it's going through Mach 1.
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#653
by
Antares
on 23 Sep, 2009 04:33
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I'd like to know what are temperatures on that altitude the space shuttle fly?
I'm assuming you're talking about the atmosphere there, rather than on the orbiter itself. I just searched for an ESTEC standard that I ran across somewhere several years ago, but I can't find it now. Maybe you can come up with more creative Google terms than me.
Basically, the individual atoms or molecules are really hot (>1000K), but they are so far apart that it would "feel" really cold (<100K).
Edit: here's a ton of models
http://ccmc.gsfc.nasa.gov/modelweb/
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#654
by
kneecaps
on 23 Sep, 2009 14:40
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On the PASS TRAJ 1 display....what does the TMECO field display in MM102?
Does it look like this TMECO XX:XX then is populated once PEG converges in MM103...or is it not present until MM102 and then appears in MM103?
Thanks in advance.
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#655
by
elmarko
on 23 Sep, 2009 14:53
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Appears at liftoff, according to Ascent Guidance workbook. I imagine as guidance converges the prediction changes.
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#656
by
kneecaps
on 23 Sep, 2009 14:58
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Appears at liftoff, according to Ascent Guidance workbook. I imagine as guidance converges the prediction changes.
So thats the question really...it appears at liftoff, but does it display XX:XX...crazy values, too high values, too low values...and then once into MM103 settles down into a good value?
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#657
by
Hobbs
on 23 Sep, 2009 16:31
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Any answers to the cost per launch question above?
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#658
by
elmarko
on 23 Sep, 2009 20:58
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Appears at liftoff, according to Ascent Guidance workbook. I imagine as guidance converges the prediction changes.
So thats the question really...it appears at liftoff, but does it display XX:XX...crazy values, too high values, too low values...and then once into MM103 settles down into a good value?
I imagine it has some sort of I-loaded value at liftoff, and then it doesn't change during 1st stage (because it's open loop, so there's no inputs from the system), and then during the cycles of convergence they change.
Whether that means going lower or higher would depend on the initial value, obviously.
Any insight from Jorge/Mkirk?
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#659
by
Mach25
on 23 Sep, 2009 21:25
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Appears at liftoff, according to Ascent Guidance workbook. I imagine as guidance converges the prediction changes.
So thats the question really...it appears at liftoff, but does it display XX:XX...crazy values, too high values, too low values...and then once into MM103 settles down into a good value?
I imagine it has some sort of I-loaded value at liftoff, and then it doesn't change during 1st stage (because it's open loop, so there's no inputs from the system), and then during the cycles of convergence they change.
Whether that means going lower or higher would depend on the initial value, obviously.
Any insight from Jorge/Mkirk?
Guidance doesn't compute TMECO until MM103.