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#720
by
Felonator
on 03 Jan, 2007 23:56
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Ah i see. All makes sense now.
Thanks Jorge and Kneecaps! Both very helpfull! And cheers for the patience with me
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#721
by
MySDCUserID
on 04 Jan, 2007 01:34
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Several times while crossing NASA Causeway, I have had to pull off of the road to let an unpainted SRB Frustrum, Forward Skirt, or Aft Skirt pass by. Do they remove the paint over at KSC and return the components to CCAFS for repainting? Or is this non-flight hardware?
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#722
by
DaveS
on 04 Jan, 2007 01:41
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kneecaps - 3/1/2007 9:36 PM
and the surfaces are elevons and ailerons.
There are no such things as ailerons on the orbiter. The elevons are combined
elevators and ailer
ons.
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#723
by
Jim
on 04 Jan, 2007 01:43
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They stored on CCAFS in front of Hangar AF.
The ARF is on KSC
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#724
by
Crispy
on 04 Jan, 2007 22:10
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Manual control of SSME gimballing! O_O Is there actually a set of circumstances where that would be a good idea?
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#725
by
mkirk
on 04 Jan, 2007 22:51
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Crispy - 4/1/2007 4:53 PM
Manual control of SSME gimballing! O_O Is there actually a set of circumstances where that would be a good idea?
I’m not sure I completely understand your question, but during second stage the SSME Thrust Vector Control is what maneuvers the vehicle (orbiter & ET). First stage control comes primarily from the SRB Nozzles.
Manual control (if required) via the RHC (rotational hand controller or “stick”) is NOT RECOMMENDED until about 90 second into the flight. This is because there is no method in place for the crew to manage "load relief". Load relief is a flight control scheme that is used to mange the aerodynamic/structural loads on the vehicle by positioning the flight controls (differentially). In other words you don’t want to rip the wings off and the Commander and Pilot have no feedback within the system that allows them to control vehicle loads during the transition thru the lower atmosphere.
As Jorge said in an earlier post, manual control is possible after the 90 second point and in second stage (i.e. after SRB SEP) with the RHC. In the SMS (shuttle mission simulator) I found the orbiter to be very responsive and precise going up hill. You can really point the orbiter where you want it and it will stay there because of the “rate command/attitude hold” flight control mode. It takes very small control inputs and assuming guidance & nav are working correctly (which is probably not the case if you had to take over manual control during ascent) it is simply a matter of centering the guidance needles on the ADI (attitude indicator or “8 ball”). You have a roll needle on the top, pitch needle on the right side, and a yaw needle on the bottom…you simply center the needles like a set of cross hairs by pointing the RHC in the direction of the particular needle. As mentioned earlier yaw is controlled by rotating/twisting the RHC to the left or right
The RHC inputs during ascent go through the DAP (digital auto pilot) and are sent out as commands to position the SSME gimbal actuators. Should roll control using this method be lost due to 2 failed engines or failed actuators for 2 of the 3 engines then a scheme called SERC (single engine roll control) will be invoked which allows the RCS jets to augment the single remaining (gimballing) engine.
Mark Kirkman
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#726
by
shuttlefan
on 04 Jan, 2007 23:52
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I recently read that Columbia " exploded " over Texas. Who else, besides me, hates the word " explode " in this instance? It " broke up ", it sure as heck didn't " explode ".
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#727
by
STS-500Cmdr
on 05 Jan, 2007 06:21
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yeah i hear that word misused 'explode' 'exploded' or 'blew up' this applies to Challenger also--Challenger was more of a 'structural breakup' for years people hav commonly thrown around those words about both accidents, both shuttles. I hear people refer to Challenger [average people who dont know better] as 'Challenger blew up' or 'the shuttle with the teacher blew up' I hear it about Columbia too. This kinda of thing comes from people who dont have a grasp on physics-people in the media and people on the street.
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#728
by
spaceshuttle
on 05 Jan, 2007 06:38
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Both vehicles disintegrated, it's just that Challenger 'had more chemicals/fuels', in a sense, to make a more fiery mess. The principles of both incidents were the same, as you stated.
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#729
by
C5C6
on 05 Jan, 2007 13:50
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can somebody show me an image that shows the exact points where the shuttle is attached to the MLP??? i still dont know that and cant imagine how the shuttle remains still and doesnt fall to a side.....thank you so much
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#730
by
Jim
on 05 Jan, 2007 13:59
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C5C6 - 5/1/2007 9:33 AM
can somebody show me an image that shows the exact points where the shuttle is attached to the MLP??? i still dont know that and cant imagine how the shuttle remains still and doesnt fall to a side.....thank you so much
Four points on the base of each SRB. Just like they are attached to the yellow GSE stands
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#731
by
C5C6
on 05 Jan, 2007 16:55
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thank you so much jim!! anyway, those 8 points must resist the entire shuttle weight, and oscillation caused by winds......isnt there the possibility of the shuttle falling to a side??
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#732
by
DaveS
on 05 Jan, 2007 17:03
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C5C6 - 5/1/2007 6:38 PM
thank you so much jim!! anyway, those 8 points must resist the entire shuttle weight, and oscillation caused by winds......isnt there the possibility of the shuttle falling to a side??
Yes there is. That's why NASA has wind rules for the Space Shuttle Vehicle(SSV) when it's out at the pad. If winds are expected to exceed 65 kts, the SSV will have to be rolled off the pad into the protective environment of the VAB.
Just browse through the
Atlantis forum and check out the STS-115 pad processing threads for more info on this.
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#733
by
Jim
on 05 Jan, 2007 17:43
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C5C6 - 5/1/2007 12:38 PM
thank you so much jim!! anyway, those 8 points must resist the entire shuttle weight, and oscillation caused by winds......isnt there the possibility of the shuttle falling to a side??
They also have to withstand the thrust of the SSME's (1.2 million lbs thrust) for more than 3 seconds before the SRB's are lit and the holddown bolts fired. Winds aren't the driving factor
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#734
by
DaveS
on 06 Jan, 2007 02:40
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#735
by
shuttlefan
on 10 Jan, 2007 21:53
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How come the Commander no longer makes the " Pc less than 50, Houston " call just before SRB sep.?
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#736
by
Jim
on 10 Jan, 2007 22:29
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shuttlefan - 10/1/2007 5:36 PM
How come the Commander no longer makes the " Pc less than 50, Houston " call just before SRB sep.?
Because there is nothing anybody can do about it
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#737
by
elmarko
on 11 Jan, 2007 01:14
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Jim - 10/1/2007 11:12 PM
shuttlefan - 10/1/2007 5:36 PM
How come the Commander no longer makes the " Pc less than 50, Houston " call just before SRB sep.?
Because there is nothing anybody can do about it
There are other calls that seem to have disappeared or appeared over the years.
Like, "Performance nominal" - I don't recall hearing that anymore. Heard it on the STS-93 video.
I think it was on STS-112, after MECO there was something called up that I didn't quite hear: "We saw
... no action" - What was this?
Also, what is the "nominal shutdown plan" ? - I've heard it called by CAPCOM and CDR on different flights, but years ago we never heard it (I think). And what is an off-nominal shutdown case in this context?
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#738
by
Jim
on 11 Jan, 2007 01:29
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-----Like, "Performance nominal" - I don't recall hearing that anymore. Heard it on the STS-93 video.
They only will call off nominal
-------I think it was on STS-112, after MECO there was something called up that I didn't quite hear: "We saw ... no action" - What was this?
Some caution and warning alert that didn't require crew action
---- Also, what is the "nominal shutdown plan" ? - I've heard it called by CAPCOM and CDR on different flights, but years ago we never heard it (I think). And what is an off-nominal shutdown case in this context?
APU shutdown per nominal time on the ascent checklist
mkirk will correct me if I am off
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#739
by
MKremer
on 11 Jan, 2007 02:04
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Another SRB question (somewhat detailed) concerning the SRBs and how they're aligned during/after stacking, and fine-tuned so their upper thrust structures correctly mate with their designated ET:
- what equipment is used to align each SRB both vertically, and with each other, during or after stacking?
- how are the upper attach points aligned to their designated ET so they mate precisely, and how are they fine-adjusted (either at the SRB frustrom/MLP base supports or otherwise)?
(I'm assuming that since the lower attachments are mostly concerned with counteracting side forces they have a bit more alignment 'freedom' available for mating.)
Thanks Jorge and Kneecaps! Both very helpfull! And cheers for the patience with me 