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#2600
by
Jim
on 24 Apr, 2012 15:16
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Would the Space shuttle have benefited from the use of a fairing during assent?
Where would be the fairing?
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#2601
by
Prober
on 24 Apr, 2012 15:28
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Would the Space shuttle have benefited from the use of a fairing during assent?
Where would be the fairing?
Thinking of an upside down L shapped fairing. Designed to cover the heat shield bottom to top, and the crew compartment. The fairing would be flaired and end near the payload bay doors.
Not sure of the space available between the orbiter bottom and the fuel tank. Hope the idea would not involve adding say 6 inches of needed space.
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#2602
by
Jim
on 24 Apr, 2012 15:37
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Would the Space shuttle have benefited from the use of a fairing during assent?
Where would be the fairing?
Thinking of an upside down L shapped fairing. Designed to cover the heat shield bottom to top, and the crew compartment. The fairing would be flaired and end near the payload bay doors.
Not sure of the space available between the orbiter bottom and the fuel tank. Hope the idea would not involve adding say 6 inches of needed space.
What is its weight, attach methods, and how does it come off, nominally and in aborts?
Its weight would reduce payload by the same amount.
Its drag would reduce payload also.
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#2603
by
MP99
on 24 Apr, 2012 17:05
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What temperature are the gasses fed into the ET as pressurant?
Prelaunch
Helium for the LH2 tank and I think nitrogen for the LOX tank
During flight, the SSME provide heated gases.
Thanks.
What temp are the gases from the SSMEs at the point they're injected?
Cheers, Martin
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#2604
by
Prober
on 24 Apr, 2012 19:19
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Would the Space shuttle have benefited from the use of a fairing during assent?
Where would be the fairing?
Thinking of an upside down L shapped fairing. Designed to cover the heat shield bottom to top, and the crew compartment. The fairing would be flaired and end near the payload bay doors.
Not sure of the space available between the orbiter bottom and the fuel tank. Hope the idea would not involve adding say 6 inches of needed space.
What is its weight, attach methods, and how does it come off, nominally and in aborts?
Its weight would reduce payload by the same amount.
Its drag would reduce payload also.
drag should be reduced (if designed right). We have gotten better since the shuttle was designed.
weight would be an issue
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#2605
by
Jim
on 24 Apr, 2012 19:25
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drag should be reduced (if designed right). We have gotten better since the shuttle was designed.
No, it will be more than the existing shuttle. It will have a larger profile and some of the shuttle is still exposed.
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#2606
by
wolfpack
on 24 Apr, 2012 19:40
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Since the shuttle blanks much of the effect of the vertical stabilizer could we assume the rudder is also somewhat blanked and hence engine power is used to aid in turns (yaw)?
I believe there is still enough control authority in the rudder.
Probably way more than enough. Stomping on rudder pedals has the effect of separating the vertical stabilizer from the fuselage in normal aircraft.
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#2607
by
Fequalsma
on 25 Apr, 2012 02:48
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From the SLWT system definition handbook, vol. I (section-page):
- The LO2 and LH2 tanks are pressurized with dry GN2 at 6 psig (+/-1) after fabrication at MAF and during shipment to KSC (3-2).
- After the stack is assembled on the MLP, both tanks are purged with GHe prior to and during prop loading (3-4, 9-6).
- Pre-launch, both tanks are pressurized with GHe, the LO2 tank at T-155 sec, and the LH2 tank at T-106 sec (3-5). Pressurization is autogenous after T-6 sec (9-7).
- Heated GN2 is used to purge the Intertank and nose cap (9-3, 9-7), and GHe is injected into the LO2 feedline aft elbow to suppress/prevent geysering (9-6).
From the LWT system definition handbook, vol. III (1988):
- GO2 ullage gas temperature is 600 deg F max at the diffuser inlet, and an average of 390 deg F at the ET/Orbiter interface.
- GH2 ullage gas temperature is 100 deg F max at the diffuser inlet, and an average of -10 deg F at the ET/Orbiter interface.
What temperature are the gasses fed into the ET as pressurant?
Prelaunch
Helium for the LH2 tank and I think nitrogen for the LOX tank
During flight, the SSME provide heated gases.
Thanks.
What temp are the gases from the SSMEs at the point they're injected?
Cheers, Martin
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#2608
by
e of pi
on 25 Apr, 2012 12:41
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Someone the other day was asking me if there were ever any issues with wind levels during roll-out of Shuttle to the pad. What were the wind limits like for rollout and then for remaining on the pad? I know they usually rolled back to the VAb in the face of hurricane threats, but can someone lay out the actual critieria involved?
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#2609
by
iskyfly
on 26 Apr, 2012 18:23
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#2610
by
MP99
on 26 Apr, 2012 18:39
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Fequalsma,
great - thanks.
cheers, Martin
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#2611
by
sivodave
on 30 Apr, 2012 20:37
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Hi all.
From the "Ascent Guidance and Flight Control Workbook", available on L2, it shown that there were difference ascent displays. In particular it is shown an ASCENT TRAJ 1, ASCENT TRAJ 2 and an ASCENT TRAJ display.
I'm getting confused because I don't understand when the ASCENT TRAJ display was used. If there were two displays already, one for first and one for second stage, why having a general ASCENT TRAJ display?
thanks very much
Davide
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#2612
by
DaveS
on 03 May, 2012 00:18
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Is each bay of the orbiter payload bay of equal length or does they vary in length?
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#2613
by
Fequalsma
on 03 May, 2012 01:48
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Is each bay of the orbiter payload bay of equal length or does they vary in length?
From the Space Shuttle Systems Summary, 1980.
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#2614
by
DaveS
on 03 May, 2012 03:05
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Is each bay of the orbiter payload bay of equal length or does they vary in length?
From the Space Shuttle Systems Summary, 1980.
Thanks. That is the kind of schematic I was looking for. It answers the question nicely with the fuselage station numbers.
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#2615
by
HelixSpiral
on 07 May, 2012 02:12
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Hi all.
From the "Ascent Guidance and Flight Control Workbook", available on L2, it shown that there were difference ascent displays. In particular it is shown an ASCENT TRAJ 1, ASCENT TRAJ 2 and an ASCENT TRAJ display.
I'm getting confused because I don't understand when the ASCENT TRAJ display was used. If there were two displays already, one for first and one for second stage, why having a general ASCENT TRAJ display?
thanks very much
Davide
ASCENT TRAJ was the display used by PASS for both first and second stage. ASCENT TRAJ 1 and 2 were the respective BFS displays for first and second stage. Starting with the OI-32 software version (STS-120), PASS used similar displays to the BFS and were also called ASCENT TRAJ 1 and 2.
The old ASCENT TRAJ display was designed mainly to assist RTLS aborts and wasn't very useful for nominal ascents.
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#2616
by
Fequalsma
on 09 May, 2012 01:51
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Does anyone have diagrams of the forward RCS module? I'd like to know where the struts supporting the prop tanks are connected, and which one buckled during STS-1.
Thanks,
F=ma
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#2617
by
DaveS
on 09 May, 2012 02:04
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Anyone know the clearance between PLB Camera B and the SRMS End Effector? Based on photos I would estimate it's no more than 3". This is with the SRMS stowed and the camera in 0/0.
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#2618
by
alk3997
on 13 May, 2012 13:43
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In this article;
http://www.nasaspaceflight.com/2011/07/atlantis-down-processing-mer-review-notes-flawless-return/
“performed flawless, bar typical GPC (General Purpose Computer) errors during rollout.”
What are these errors, causes and where can I find out more about this?
Thanks
It wasn't an error in some ways but an expected condition. At this point in the flight, the orbiter was stopped near the end of the runway. Entry guidance was still running in OPS 3. As you can imagine entry guidance was designed for a forward moving vehicle not one that should be stopped.
If the crew jumped up and down (excited crew) or the wind caused the vehicle to bounce up and down on the landing gear while stopped (vertical motion but no horizontal motion), entry guidance would generate a message saying we went through a math issue (tan 90 or divide by zero, I forget). The GPC software's math routines handled the issue and there was never a real problem.
We could have easily have changed this to not have messages occur (we wouldn't have changed the math), but why tinker with code that was working fine for a part of "flight" that really wasn't flight? As soon as we went to OPS 9, the messages stopped since OPS 9 was designed for being stopped near the end of the runway.
So, not an oversight and not an error in reality. It also gave the on-console folks a chance to guess how many "error messages" would be received, which depended upon winds, crew exhuberance and time in OPS 3 while stopped.
As far as I know, unless you find the user note (which says to ignore the messages), there is no other documentation available.
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#2619
by
alk3997
on 13 May, 2012 13:51
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Hi all.
From the "Ascent Guidance and Flight Control Workbook", available on L2, it shown that there were difference ascent displays. In particular it is shown an ASCENT TRAJ 1, ASCENT TRAJ 2 and an ASCENT TRAJ display.
I'm getting confused because I don't understand when the ASCENT TRAJ display was used. If there were two displays already, one for first and one for second stage, why having a general ASCENT TRAJ display?
thanks very much
Davide
ASCENT TRAJ was the display used by PASS for both first and second stage. ASCENT TRAJ 1 and 2 were the respective BFS displays for first and second stage. Starting with the OI-32 software version (STS-120), PASS used similar displays to the BFS and were also called ASCENT TRAJ 1 and 2.
The old ASCENT TRAJ display was designed mainly to assist RTLS aborts and wasn't very useful for nominal ascents.
The newer PASS Ascent Traj displays were collectively known as 6X Traj (or XXXXXX TRAJ) since the XXXXXX could be changed from ASCENT to an abort name. RTLS TRAJ was significantly different than ASCENT TRAJ. The newer displays were an attempt to implement some of what had been planned with CAU display work.
