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#360
by
blazotron
on 10 Jun, 2007 05:45
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Here's one for you:
What are the radial grooves in the area around some of the RCS nozzles? The grooves look like they are in HRSI, but I dont think they actually are (they look to be in a bolted-on plate of some kind, maybe columbium like the nozzles themselves?). Up till a few minutes ago, I had been thinking that the grooves were some sort of aerothermal device to improve the heating or aerodynamics around the jets upon reentry. But after getting a good close look at them, I am now thinking that they might be stiffeners in the plate that seems to cover the the area around the nozzle and chamber of the inclined RCS engines (ie not the ones that point normal to the surface).
Here is an example image showing some of the grooves:
linkCan anyone confirm the real porpose?
While I'm at it, what are the other holes visible in this image: two elongated holes in the upper right quadrant of the image, near the white/black boundary, a large hole at the very top of the image on the right side, and a small hole about 2/3 of the way from the center of the image to the nosecap.
Thanks for the help!
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#361
by
dawei
on 10 Jun, 2007 11:37
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I believe the elongated slot by the white/black boundry is for the Air Date Probe used during the landing phase. The bigger, rounder area above that is a star tracker. That is all the help I can give you.
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#362
by
Jorge
on 10 Jun, 2007 12:33
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dawei - 10/6/2007 6:37 AM
I believe the elongated slot by the white/black boundry is for the Air Date Probe used during the landing phase. The bigger, rounder area above that is a star tracker. That is all the help I can give you.
The air data probe "door" is actually a lot further down in the image, below the bottom of the seam separating the forward RCS pod from the rest of the forward fuselage.
The elongated slot is a vent door.
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#363
by
mkirk
on 10 Jun, 2007 14:28
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Jorge - 10/6/2007 7:33 AM
dawei - 10/6/2007 6:37 AM
I believe the elongated slot by the white/black boundry is for the Air Date Probe used during the landing phase. The bigger, rounder area above that is a star tracker. That is all the help I can give you.
The air data probe "door" is actually a lot further down in the image, below the bottom of the seam separating the forward RCS pod from the rest of the forward fuselage.
The elongated slot is a vent door.
Yes, and the two elongated slots are Vent Doors 1 and 2. There are identical doors on the other side of the nose. Vent Door 1 is for the forward RCS cavity and Vent Door 2 is for the forward fuselage and also includes the nose wheel well.
Mark Kirkman
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#364
by
dawei
on 10 Jun, 2007 15:10
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Well.... I learn something new almost every day here and that is a great thing.
Thanks Mark and Jorge!
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#365
by
j2_
on 11 Jun, 2007 00:57
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How come we never see the payload bay door radiators deployed on orbit anymore?
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#366
by
Jim
on 11 Jun, 2007 01:22
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Shuttle isn't producing the same heat load on ISS missions as for others, especially when docked
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#367
by
Zoomer30
on 11 Jun, 2007 02:00
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Ok dumb question here. I was watching the video from a launch last year (cant remember the number) that was an SRB shot looking down the right SRB. You could see the right wing of the orbiter and both the inner and outer elevons. The thing i wonder about is why do the elevons move into an up position as the shuttle asends? As the ascent progressed, you could see first the outer elevon flap moved up and then the inner elevon moved up. I would think at that height there would be very little air left for these flaps to work with for steering.
Is it just so they stay out of the SRB plume recirculation?
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#368
by
MKremer
on 11 Jun, 2007 02:22
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It's to control aero loading on the orbiter structure. This is also covered in more detail in one of the earlier Shuttle Q&A threads.
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#369
by
kneecaps
on 11 Jun, 2007 15:49
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The daily execute packages always give information on 'OMS TANK FAIL CAPABILITY'...is this the capability to complete the mission if both tanks in a pod were rendered unusable?
Also the same document also mentions for 'LEAKING OMS PRPLT BURN' to 'ALWAYS RETROGRADE' (makes sense) but I have seen it say 'OOP' in the past. I'm wondering what OOP is and in what situations would you continue to use an OMS engine with leaking tanks.
Thanks!
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#370
by
j2_
on 11 Jun, 2007 19:11
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kneecaps - 11/6/2007 8:49 AM
Also the same document also mentions for 'LEAKING OMS PRPLT BURN' to 'ALWAYS RETROGRADE' (makes sense) but I have seen it say 'OOP' in the past. I'm wondering what OOP is and in what situations would you continue to use an OMS engine with leaking tanks.
Thanks!
I believe OOP refers to "Out of plane". That means burning the engine orbit normal or anti-normal (perpendicular to the velocity vector), which is an effective way to use up the leaking fuel, because plane change maneuvers are very expensive in terms of delta-v, and burning the OMS engines out of plane won't affect the shuttle trajectory much.
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#371
by
Danny Dot
on 11 Jun, 2007 22:22
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kneecaps - 11/6/2007 10:49 AM
The daily execute packages always give information on 'OMS TANK FAIL CAPABILITY'...is this the capability to complete the mission if both tanks in a pod were rendered unusable?
Also the same document also mentions for 'LEAKING OMS PRPLT BURN' to 'ALWAYS RETROGRADE' (makes sense) but I have seen it say 'OOP' in the past. I'm wondering what OOP is and in what situations would you continue to use an OMS engine with leaking tanks.
Thanks!
I used to teach this subject to the astronauts, but it has been a while. The idea is an OMS burn will be accomplished after the leak is detected, but before all the propellant leaks out. Always retro grade means the current orbit's perigee must be lowered some by the leaking system, or the shuttle will not be able to come home with the non-leaking pod. The problem with Alway Retrograde is the perigee may be lowered in the Southern Hemisphere, which would force the shuttle to do the second OMS burn such that a landing in the Southern Hemisphere is the only option. Obviously, landing in Australia , would be a pain in the rear -- the 747 would have to go down and pick the shuttle up. But a landing in Australia would be better than being stuck in orbit "forever". If the leaking OMS tank is burned Out Of Plane, this means there is enough prop in the other tank to allow it to do a deorbit burn (along with RCS prop) from the current orbit.
This is a simplification, there are other things to consider such as shallow entry, but I hope this helps somewhat.
Danny Deger
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#372
by
kneecaps
on 12 Jun, 2007 19:59
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Danny Dot - 11/6/2007 11:22 PM
I used to teach this subject to the astronauts, but it has been a while. The idea is an OMS burn will be accomplished after the leak is detected, but before all the propellant leaks out. Always retro grade means the current orbit's perigee must be lowered some by the leaking system, or the shuttle will not be able to come home with the non-leaking pod. The problem with Alway Retrograde is the perigee may be lowered in the Southern Hemisphere, which would force the shuttle to do the second OMS burn such that a landing in the Southern Hemisphere is the only option. Obviously, landing in Australia , would be a pain in the rear -- the 747 would have to go down and pick the shuttle up. But a landing in Australia would be better than being stuck in orbit "forever". If the leaking OMS tank is burned Out Of Plane, this means there is enough prop in the other tank to allow it to do a deorbit burn (along with RCS prop) from the current orbit.
This is a simplification, there are other things to consider such as shallow entry, but I hope this helps somewhat.
Danny Deger
Thanks for that makes it very clear, does the 'OMS TANK FAIL' also refer to the same thing but not in case of a leak? Maybe a He failure, which presumably you wouldn't burn off the fuel?
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#373
by
Danny Dot
on 12 Jun, 2007 22:37
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kneecaps - 12/6/2007 2:59 PM
Danny Dot - 11/6/2007 11:22 PM
I used to teach this subject to the astronauts, but it has been a while. The idea is an OMS burn will be accomplished after the leak is detected, but before all the propellant leaks out. Always retro grade means the current orbit's perigee must be lowered some by the leaking system, or the shuttle will not be able to come home with the non-leaking pod. The problem with Alway Retrograde is the perigee may be lowered in the Southern Hemisphere, which would force the shuttle to do the second OMS burn such that a landing in the Southern Hemisphere is the only option. Obviously, landing in Australia , would be a pain in the rear -- the 747 would have to go down and pick the shuttle up. But a landing in Australia would be better than being stuck in orbit "forever". If the leaking OMS tank is burned Out Of Plane, this means there is enough prop in the other tank to allow it to do a deorbit burn (along with RCS prop) from the current orbit.
This is a simplification, there are other things to consider such as shallow entry, but I hope this helps somewhat.
Danny Deger
Thanks for that makes it very clear, does the 'OMS TANK FAIL' also refer to the same thing but not in case of a leak? Maybe a He failure, which presumably you wouldn't burn off the fuel?
Sorry, I don't remember. I stopped training astronauts in 1995.
Danny Deger
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#374
by
kneecaps
on 12 Jun, 2007 22:54
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Sorry, I don't remember. I stopped training astronauts in 1995.
Danny Deger
Thanks still! What you did remember was great
Always love to hear from the pros!
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#375
by
Wolverine
on 13 Jun, 2007 00:58
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I have 2 questions.
1. Can the shuttle do a skip glide re-entry?
2. Of the STS budget, how much $$$ is actually for orbiter vehicle prep/upkeep and how much is for the boosters and ET? I'm looking for a rough percentage.
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#376
by
hyper_snyper
on 13 Jun, 2007 01:56
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#377
by
j2_
on 13 Jun, 2007 02:01
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#378
by
Danny Dot
on 13 Jun, 2007 02:13
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Wolverine - 12/6/2007 7:58 PM
I have 2 questions.
1. Can the shuttle do a skip glide re-entry?
snip
When I first started training astronauts in 1990, I was told if the shuttle skipped the second entry would be too seviour to survive. In about 1992, I tried one in the high fedility simulator and it worked OK. The second entry was very mild.
Danny Deger
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#379
by
kneecaps
on 13 Jun, 2007 21:46
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Just a quickie. What is an OI TFL...I know the OI bit..but whats a TFL?
Thanks in advance!
