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#3320
by
mtakala24
on 16 Jan, 2015 15:02
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I played around a bit in VLC. The background (Earth, clouds) is a total white-out for the most part. Are you trying to match the brightness of the shuttle itself in STS-133? I couldn't get a good result for that either.
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#3321
by
ZachS09
on 16 Jan, 2015 15:13
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Yup. I needed to someday change the settings to make the STS-134 ET Cam footage look like all others in daytime.
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#3322
by
sivodave
on 17 Jan, 2015 22:22
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Hello all.
Questions about the Power Extension Package. In particular: Why was PEP discarded? And when did the idea die out?
Thanks very much and have a good weekend.
Davide
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#3323
by
Lee Jay
on 18 Jan, 2015 01:10
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SSME question.
If I look straight into an SSME all the way to the center, I see a gold colored section (part of the nozzle prior to the regenerative part?) and a silver colored section with a lot of holes in it behind that. Is that the main combustion chamber and the injectors? I know this is somehow ITAR protected so I'm not sure I can post a picture I took at Udvar Hazy even though this area was sometimes visible even in the RPM photos.
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#3324
by
joncz
on 18 Jan, 2015 13:38
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#3325
by
Lee Jay
on 18 Jan, 2015 13:59
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#3326
by
Hog
on 19 Jan, 2015 14:35
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I watching a Wayne Hale presentation at MIT and he was talking about when faulty data was uploaded into the computers locating the Orbiter somewhere in the Andromeda galaxy or similar, and the Shuttle began spinning at 3 second thus losing comms for 10 minutes.
Mr Hale does state the mission number, but it is garbled. Can anyone confirm which STS mission this was?
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#3327
by
Hog
on 20 Jan, 2015 16:29
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It was STS-32.
On FD 9 during crew sleep, INCO uploaded some bad state vector into the Inertial Navigation System which resulted in loss of attitude control. Had the RCS been "on the big jets" there may not have been enough RCS fuel left for safe re-entry. Thankfully the RCS was configured for the "small jets".
The loss of attitude control resulted in a 10 minute loss.
Mr Hale explains the cascade of human errors involved in this incident.
STS-32 incident discussion starts at 1:35:00
http://videolectures.net/mit16885f05_hale_lec18/
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#3328
by
Lee Jay
on 27 Jan, 2015 22:17
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I'm studying STS-93 and a question has come up that I can't answer. From Wayne Hale's blog post:
Regarding the hydrogen leak from the nozzle, "Since the chamber pressure dropped slightly due to the loss of fuel for the fire in the main combustion chamber, the SSME controller commanded more oxygen be sent to the MCC. "
What I don't understand is why the chamber pressure dropped. If the engine is running fuel-rich, all the oxygen is being consumed even if there's a slight loss of fuel flow. So, the same chemical reaction should be happening, albeit with a slightly lower mass flow and a slightly lower mixture ratio. So why did the main combustion chamber pressure drop?
What am I missing here?
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#3329
by
wolfpack
on 28 Jan, 2015 14:20
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I'm studying STS-93 and a question has come up that I can't answer. From Wayne Hale's blog post:
Regarding the hydrogen leak from the nozzle, "Since the chamber pressure dropped slightly due to the loss of fuel for the fire in the main combustion chamber, the SSME controller commanded more oxygen be sent to the MCC. "
What I don't understand is why the chamber pressure dropped. If the engine is running fuel-rich, all the oxygen is being consumed even if there's a slight loss of fuel flow. So, the same chemical reaction should be happening, albeit with a slightly lower mass flow and a slightly lower mixture ratio. So why did the main combustion chamber pressure drop?
What am I missing here?
The fuel rich condition means excess hydrogen injected into the chamber doesn't react with the oxygen, but it certainly gets heated and expands against the chamber walls. Take that away means less chamber pressure, doesn't it?
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#3330
by
Lee Jay
on 28 Jan, 2015 14:24
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I'm studying STS-93 and a question has come up that I can't answer. From Wayne Hale's blog post:
Regarding the hydrogen leak from the nozzle, "Since the chamber pressure dropped slightly due to the loss of fuel for the fire in the main combustion chamber, the SSME controller commanded more oxygen be sent to the MCC. "
What I don't understand is why the chamber pressure dropped. If the engine is running fuel-rich, all the oxygen is being consumed even if there's a slight loss of fuel flow. So, the same chemical reaction should be happening, albeit with a slightly lower mass flow and a slightly lower mixture ratio. So why did the main combustion chamber pressure drop?
What am I missing here?
The fuel rich condition means excess hydrogen injected into the chamber doesn't react with the oxygen, but it certainly gets heated and expands against the chamber walls. Take that away means less chamber pressure, doesn't it?
I suppose, a little, but the difference would be quite small, I would think.
I'm now thinking that maybe the difference is less fuel to the turbines, making them run slower and thus pump less fuel and oxygen to the combustion chamber. But I don't know if that's true either!
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#3331
by
MikeEndeavor23
on 29 Jan, 2015 05:34
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Anyone remember when NASA made the decision to change the back stripe on the edge of the Shuttle wings to white squares?
Was it done after their long maintenance periods? Also, why the transition from black to white? Was it for looks or did it serve a specific function?
MikeEndeavor23
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#3332
by
Hog
on 02 Feb, 2015 11:55
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Anyone remember when NASA made the decision to change the back stripe on the edge of the Shuttle wings to white squares?
Was it done after their long maintenance periods? Also, why the transition from black to white? Was it for looks or did it serve a specific function?
MikeEndeavor23
I shouldn't do this, but here is a Wiki article on STS's Thermal Protection System(TPS).
http://en.wikipedia.org/wiki/Space_Shuttle_thermal_protection_systemConsider the source, but it should answer most of your questions.
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#3333
by
DaveS
on 10 Feb, 2015 09:25
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Does anyone know where the floor is in the External Airlock? I mean the floor of the crew accessible area of the airlock. Is it the bottom of the cylindrical section or the bottom on conical section?
Edit:
Also, outer diameters of the ODS vestibule and the Structural Ring?
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#3334
by
yatpay
on 10 Feb, 2015 18:55
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While reading the book "Comm Check..." about STS-107, I read that there was a 1/10 inch gap behind the top of the leading edges of the wings to allow pressure equalization within the wings. I was just curious if anyone could tell me more about that or any other similar open spaces on the vehicle. How did they keep water or insects out? My first thought was maybe it was covered similar to the RCS ports but I couldn't recall seeing covers falling off during launch.
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#3335
by
Jim
on 10 Feb, 2015 19:01
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While reading the book "Comm Check..." about STS-107, I read that there was a 1/10 inch gap behind the top of the leading edges of the wings to allow pressure equalization within the wings. I was just curious if anyone could tell me more about that or any other similar open spaces on the vehicle. How did they keep water or insects out? My first thought was maybe it was covered similar to the RCS ports but I couldn't recall seeing covers falling off during launch.
http://spaceflight.nasa.gov/shuttle/reference/shutref/purge/
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#3336
by
yatpay
on 10 Feb, 2015 19:02
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While reading the book "Comm Check..." about STS-107, I read that there was a 1/10 inch gap behind the top of the leading edges of the wings to allow pressure equalization within the wings. I was just curious if anyone could tell me more about that or any other similar open spaces on the vehicle. How did they keep water or insects out? My first thought was maybe it was covered similar to the RCS ports but I couldn't recall seeing covers falling off during launch.
http://spaceflight.nasa.gov/shuttle/reference/shutref/purge/
Oh perfect! Thanks very much!
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#3337
by
Hog
on 18 Feb, 2015 14:50
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The Filament Wound Case (FWC) designed for STS/Vandenberg polar flights was roughly 25,000lbs lighter than the 1/2" steel cases for lower inclination KSC launches.
1)Approx. how much extra payload mass would 25,000lbs decrease in booster weight allow for? (not worrying about the effects of inclination in this question-IIRC Jim stating its about 625lb/º and approx. 100lbs/nautical mile for altitude)
2) What effects does weight savings on the ET have on net payload capability?
3) Is weight savings on the Orbiter on a 1 to 1 ratio (a pound saved from orbiter weight, is a pound of added payload)?
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#3338
by
AnalogMan
on 18 Feb, 2015 15:01
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The Filament Wound Case (FWC) designed for STS/Vandenberg polar flights was roughly 25,000lbs lighter than the 1/2" steel cases for lower inclination KSC launches.
1)Approx. how much extra payload mass would 25,000lbs decrease in booster weight allow for? (not worrying about the effects of inclination in this question-IIRC Jim stating its about 625lb/º and approx. 100lbs/nautical mile for altitude)
The decrease in FWC mass was expected at the time to increase Shuttle lift capability by 4,600 lb.
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#3339
by
Jim
on 18 Feb, 2015 16:42
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ET savings were almost 1 for 1 and orbiter was one for one
