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#3380
by
iskyfly
on 20 Aug, 2015 02:31
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STS-125 launch. ASA 1 failure. CAPCOM calls up, "bypass across the board".
Is that an instruction to do something, if so, what? Or was it informational and if so what did it mean?
Thanks!
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#3381
by
Graham
on 20 Aug, 2015 15:10
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STS-125 launch. ASA 1 failure. CAPCOM calls up, "bypass across the board".
Is that an instruction to do something, if so, what? Or was it informational and if so what did it mean?
Thanks!
I'm sure someone will correct me if I'm wrong, but I believe it meant that ASA 1 was being bypassed since it had failed. In fact I believe the next call up was "No action required".
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#3382
by
mkirk
on 21 Aug, 2015 03:10
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STS-125 launch. ASA 1 failure. CAPCOM calls up, "bypass across the board".
Is that an instruction to do something, if so, what? Or was it informational and if so what did it mean?
Thanks!
I'm sure someone will correct me if I'm wrong, but I believe it meant that ASA 1 was being bypassed since it had failed. In fact I believe the next call up was "No action required".
ASA = Aerosurface Servo Amplifier. There are four of these (ASAs) that act like the brain of the hydraulic actuators used to move the orbiter's aerosurfaces (elevons, speedbrake, and rudder). Each actuator has 4 servo valves (or ports) and a single ASA (1,2,3 or 4) is assigned to each one of those 4 servo valves on each of the hydraulic actuators. In other words, each actuator is redundantly controlled by 4 ASAs.
During ignition and liftoff of Atlantis on STS-125, the power to ASA 1 failed and all the ports assigned to that ASA on each actuator were bypassed to effectively take ASA 1 out of the loop and allow the remaining ASAs (2,3, and 4) to continue to do their job. A message was displayed to the crew by the GPC (general purpose computers) and Scott Altman (Scooter) reported that fact to Houston right as the roll maneuver was being performed. They confirmed that all the ports on ASA 1 bypassed. As long as all the ports automatically bypass, then the procedures require no action by the crew.
A single ASA failure was considered a loss of redundancy, more than that, depending on the number and timing of the failures, and you could potentially be talking about an abort or terminating the mission early (i.e. next PLS - Primary Landing Site opportunity).
Mark
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#3383
by
iskyfly
on 21 Aug, 2015 14:33
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Thank you Graham and Mark.
If I remember correctly, this occurred during SSME ignition before SRB ignition. Why then, didn't the launch abort before liftoff?
Thank you!
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#3384
by
mkirk
on 22 Aug, 2015 03:44
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I really don't remember. It was presumably a function of how and when the LCC (Launch Commit Criteria) for this system's parameters were monitored. Could be it was only a launch limit violation up to T-31 seconds or T-10 seconds.
Mark
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#3385
by
iskyfly
on 28 Aug, 2015 18:22
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In regards to my previous questions re STS-125 ASA 1, this is the mission control ascent vid;
-What is "2 stage" (after liftoff and before in the bucket) ?
-What does booster mean when he says;
"3 fids are all invalid, invalid family and delimiter. Good norm. Crew has no insight"?
"impact the crew calling an engine out behind a data path"?
Oh, and if there is backroom audio ala STS-93 I'd love to hear that.
Thanks!
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#3386
by
hamzah
on 31 Aug, 2015 03:38
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hi guys i'm new to the forum,and i have a question on the space shuttle pumping system, i'm a mechanical engineer who worked on hydraulic efficiency pump improvement research at the university were we improved the efficiency of heart assistant device (VBA) and Berkeley pump by simulations and real testing.I'm getting ready to apply our theory/methods of improvement on space pump put before i can apply it i need to know what type of pumps the space shuttle uses in space ? and what forces the pumps experience while operating in space ? and if possible the schismatic of the pumps used and the pumping system?
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#3387
by
Jim
on 31 Aug, 2015 12:21
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Pumps for what systems?. There were many pumps on the shuttle
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#3388
by
hamzah
on 04 Sep, 2015 15:15
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sorry i didn't specify, i want any pumping system and type pump schamatic that is used in shuttle while flying in space, and if it possible to specify the use of it so i could simulate it in detail using the sofware
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#3389
by
baldusi
on 04 Sep, 2015 17:32
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sorry i didn't specify, i want any pumping system and type pump schamatic that is used in shuttle while flying in space, and if it possible to specify the use of it so i could simulate it in detail using the sofware
Do you mean the pumps on the rocket engines turbopump? The pumps on the heat rejection system? The onboard water supply pumps? The hydraulic actuators' pump? The pneumatic pressurization pump?
In space nothing flows by gravity. Any fluid will need to be moved by a pump or blade.
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#3390
by
hamzah
on 04 Sep, 2015 18:23
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actully all those pumps will work in my software
, and if possible my professor wants to know were can he apply and who he needs to contact for NASA grants to fund the research ?
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#3391
by
ZachS09
on 20 Sep, 2015 19:59
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According to a PDF file dating back to June 2001 (
www.nasa.gov/pdf/2254main_tm210880.pdf), there were five previous shuttle missions including STS-95 that featured the first SRB-intertank cameras. Is there any way to obtain the SRB cam footage from the other four:
STS-93
STS-96
STS-101
STS-103
I would appreciate it.
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#3392
by
hamzah
on 20 Sep, 2015 22:39
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can anyone give me the schismatic of the onboard water supply pumps that is used on the shuttle to simulate please?
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#3393
by
Jim
on 20 Sep, 2015 22:51
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can anyone give me the schismatic of the onboard water supply pumps that is used on the shuttle to simulate please?
There wasn't pumps used to move water. It just use pressure and diaphragms.
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#3394
by
Johnnyhinbos
on 25 Dec, 2015 14:24
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Not sure where this is best posted, but here's an interesting article on a proposed conversion of the shuttle's main engines to a full flow staged conversion version. A conversion that never happened.
I find it of particular interest when used as a metric for engine reuse and the issues and expense that the SSME had. Therefore this may best be placed in the SpaceX thread on reuse...
http://www.eaglehill.us/programs/journals/spaevo/2015a1/
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#3395
by
JAFO
on 30 Dec, 2015 00:30
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I met these two fine people during the media tour of Discovery in the OPF before the STS-134 launch, but I've lost my notes about who they are. I know there are people here who do.....
TIA
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#3396
by
rayleighscatter
on 30 Dec, 2015 01:16
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I think the woman on the left is Stephanie Stilson, Discovery's flow director.
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#3397
by
JAFO
on 30 Dec, 2015 01:44
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I think the woman on the left is Stephanie Stilson, Discovery's flow director.
That's her, thanks.
The gentleman had something to do with security. Before entering the OPF we had been given very precise instructions to stay within the red lines on the floor. At one point I wanted to try to lean over the line and see if I could see Discovery's name and get an image of it. I explained what I was doing to him and got a quiet nod, while I was doing so another person thought I was pushing the boundary a bit too far and came over to give me a warning. I accepted the warning, and promised to be good. A couple minutes later he came over and demanded my camera. My heart sank but I handed it over and he disappeared, telling me to stay put. A few minutes later he returned and handed my camera back without a word. He had gone up and taken the two images below for me.
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#3398
by
Hog
on 07 Jan, 2016 19:21
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What kind of temperatures are experienced by the Shuttle during ascent?
After MECO, what composes the various particles/debris that are seen escaping from the Orbiter?
How long after MECO are the payload bay doors opened?
TIA
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#3399
by
tminus9
on 07 Jan, 2016 20:30
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How long after MECO are the payload bay doors opened?
According to the STS-135 mission report, MECO was at 00/00:08:24 MET and payload bay doors were opened at 00/01:34:16 MET, so in that case it was roughly 90 minutes after MECO. I don't know how that varied over the program's history, but I'd suspect it was similar since the orbiter can't stay in orbit long without opening the doors.
, and if possible my professor wants to know were can he apply and who he needs to contact for NASA grants to fund the research ?