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#240
by
Chris Bergin
on 02 Mar, 2007 12:31
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SimonFD - 2/3/2007 1:06 PM
What contingency ops are there in case of accidental SRB ignition? I though once they were going that was that for two minutes or so!
You'll have to excuse me i'm new here 
Welcome to the site
Undesired SRB ingition is bad, period. That has LOV (Loss of Vehicle) written all over it.
The worst situation is at launch, if only one lights. Hugely unlikely, but (and a good place to check) on Shuttle Q and A this is discussed.
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#241
by
charlieb
on 02 Mar, 2007 13:21
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Single SRB ignition scenario is HIGHLY unlikely with all the redundancy available (NSI's, cabling, capacitor banks, etc...). BUT - IF it were to occur - yes a definate LOV and LOP (loss of Pad).
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#242
by
kevin-rf
on 02 Mar, 2007 14:07
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nathan.moeller - 2/3/2007 7:30 AM
SimonFD - 2/3/2007 7:06 AM
What contingency ops are there in case of accidental SRB ignition? I though once they were going that was that for two minutes or so!
You'll have to excuse me i'm new here
Welcome to the site Simon. Probably better for the Shuttle Q&A section in the general discussion forum. 
But SRBs have self-destruct charges that can be detonated by the RSO (Range Safety Officer). The only time that has happened was STS-51L (Challenger Accident). The boosters were destroyed about 37 seconds after the disintegration of Challenger and the ET.
There is always an RSO sitting with his finger on the switch? I think if an SRB was ignited outside of a normal countdown (thunder boomer moves through and strikes the booster instead of the lightening supression system) there would be no one to throw the switch. I sure one of NASA's biggest fears is a SRB lighting inside the VAB. It would be a curtain call for the Shuttle,Ares I, and Ares V. One only has to look at what happened on the pad in brazil a few years back to get an idea of how bad it would be.
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#243
by
nathan.moeller
on 02 Mar, 2007 14:59
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kevin-rf - 2/3/2007 9:07 AM
nathan.moeller - 2/3/2007 7:30 AM
SimonFD - 2/3/2007 7:06 AM
What contingency ops are there in case of accidental SRB ignition? I though once they were going that was that for two minutes or so!
You'll have to excuse me i'm new here
Welcome to the site Simon. Probably better for the Shuttle Q&A section in the general discussion forum. But SRBs have self-destruct charges that can be detonated by the RSO (Range Safety Officer). The only time that has happened was STS-51L (Challenger Accident). The boosters were destroyed about 37 seconds after the disintegration of Challenger and the ET.
There is always an RSO sitting with his finger on the switch? I think if an SRB was ignited outside of a normal countdown (thunder boomer moves through and strikes the booster instead of the lightening supression system) there would be no one to throw the switch. I sure one of NASA's biggest fears is a SRB lighting inside the VAB. It would be a curtain call for the Shuttle,Ares I, and Ares V. One only has to look at what happened on the pad in brazil a few years back to get an idea of how bad it would be.
I was actually thinking about accidental ignition during the countdown. As for any other time, I have no idea
Just pray it goes up and away into the Atlantic. Yeah, ignition in the VAB mean NASA is done with any launch operations for several years.
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#244
by
voyager
on 02 Mar, 2007 16:06
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Not to change the subject of SRB's but ran across some historical images of the last rollback of STS-96.
This will give you an idea as to how intensive the repairs can be and why these repairs are not performed at the pad.
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#245
by
rdale
on 02 Mar, 2007 16:12
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kevin-rf - 2/3/2007 10:07 AM
I sure one of NASA's biggest fears is a SRB lighting inside the VAB.
I am even more certain that such an event is WAY WAY WAY, WAY down on the NASA Fear List...
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#246
by
STS-500Cmdr
on 02 Mar, 2007 17:52
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I imagine there are good safety inhibits in place to prevent any accidental ignition by lightning or whatever--much like what youd see on an aircraft carrier or an air base with the ordnance--bombs, missiles, etc-as well as ejection seats in jets-those safety pins with the red tags-REMOVE BEFORE FLIGHT.
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#247
by
publiusr
on 02 Mar, 2007 18:52
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MKremer - 1/3/2007 9:12 PM
shuttlefan - 1/3/2007 7:51 PM
I read that Brevard County is under a Tornado Watch.
Not "dumb luck", but just the rarity of that type of thunderstorm at the Cape (also note that in the past almost-50 years there hasn't been that type of "violent, quick-storm" that has resulted in major damages to either NASA or Pentagon LVs, or the support/fueling structures around them.)
Also, many Florida tornadoes are little more than Waterspouts/Landspouts, though an occasional larger vortex like what struck Florida recently can occur as well.
The current system moving through may produce more hail. This was the system that destroyed the High School in Enterprise, Alabama...my home state:
http://attackmachine.proboards56.com/index.cgi?board=onair&action=display&thread=1172846755I've seen what a tornado can do to a large school, having assisted with the survey of the Oak Grove tornado from 1998...so luck can have something to do with high value 'targets.'
I seem to remember a waterspout photographed behind a shuttle stack from a couple of years ago IIRC.
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#248
by
Chris Bergin
on 02 Mar, 2007 20:02
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voyager - 2/3/2007 5:06 PM
Not to change the subject of SRB's but ran across some historical images of the last rollback of STS-96.
This will give you an idea as to how intensive the repairs can be and why these repairs are not performed at the pad.
Wonderful images.
Reminds me of the image of platform access used to changeout the LOX vent and relief valve on ET-119.
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#249
by
psloss
on 02 Mar, 2007 21:55
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#250
by
jmjawors
on 02 Mar, 2007 23:24
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EDIT #2:: I've edited this post to Kingdom Come... so I'll just repost what I had:
anik - 1/3/2007 12:13 PM
According to current plan, there will be Soyuz TMA-10 relocation from Zvezda module to Zarya module on April 27 and possible ISS orbit's raisings by Zvezda's engines for preparation to STS-117 and Progress M-60...
These events can not be postponed, therefore it means that STS-117 launch is possible from the beginning of May only...
On NASA.gov today:
A planned altitude reboost for the space station on Friday was cancelled and rescheduled for later this month. With the launch of the STS-117 shuttle mission delayed until no earlier than late April, Russian flight controllers now plan on two separate reboosts for the station.
The first reboost, now planned for around March 16, will position the station for the launch of the Expedition 15 crew and U.S. businessman Charles Simonyi on the Soyuz TMA-10 craft from the Baikonur Cosmodrome on April 7.
A second reboost on March 28 improves rendezvous opportunities for Atlantis’ flight and brings the station into the correct trajectory for the returning Soyuz craft to land in Kazakhstan on April 19 with Expedition 14 Commander Mike Lopez-Alegria, Flight Engineer Mikhail Tyurin and Simonyi.
Two issues here, the reboost and the relocation. But so far NASA does not seem to be addressing the "Soyuz relocation" aspect of all this. At least not on the website.
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#251
by
DaveS
on 02 Mar, 2007 23:50
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jmjawors - 3/3/2007 1:24 AM
Two issues here, the reboost and the relocation. But so far NASA does not seem to be addressing the "Soyuz relocation" aspect of all this. At least not on the website.
They probably have nothing new to report at this time on this. They're probably still talking about it. I don't see any reason why it couldn't be postponed.
I think that the Russians have gotten a little
bit too comfortable with slack in the ISS schedule during the downtime between STS-107/STS-114 and STS-114/STS-121.
Now the shuttle is back and it's time to get used to the fact that assembly has restarted and there's no more slack in the schedule.
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#252
by
Michael22090
on 03 Mar, 2007 01:03
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I notice that the NASA TV schedule does not list the rollback. Does anyone know if it will be shown? I would like to see at least part of it...
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#253
by
nathan.moeller
on 03 Mar, 2007 02:09
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Michael22090 - 2/3/2007 8:03 PM
I notice that the NASA TV schedule does not list the rollback. Does anyone know if it will be shown? I would like to see at least part of it...
Probably not. We usually stick to screen caps from the NASA webcams on here to give coverage. It's not a heck of an event to keep up with on here but at least we can track it. The most exciting rollout/rollback event we've seen was the STS-115 rollback reversal back in August. Big excitement there but we know that isn't going to happen this time around. We can expect at least 26 days in the VAB.
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#254
by
anik
on 03 Mar, 2007 06:24
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DaveS - 3/3/2007 3:50 AM
I don't see any reason why it couldn't be postponed.
I think that the Russians have gotten a little bit too comfortable with slack in the ISS schedule during the downtime between STS-107/STS-114 and STS-114/STS-121.
Now the shuttle is back and it's time to get used to the fact that assembly has restarted and there's no more slack in the schedule
I will answer to the first sentence only and ignore other two...
There will be two spacecrafts on ISS after Soyuz TMA-9 landing: Progress M-59 - on Pirs module and Soyuz TMA-10 - on Zvezda module... Progress M-59 is unprofitable for performing maneuvers of changing ISS orbit... The using of Soyuz TMA-10 engines for such purposes is dangerously...
"If" Space Shuttle will enter very low orbit then, according to agreement between Russian and U.S. specialists, ISS must lower orbit by approximately 100 kilometres... In this situation we can perform such maneuver with using Zvezda's engines only... Therefore Soyuz TMA-10 must be relocated from Zvezda module to Zarya module prior to STS-117 launch...
I am not a specialist, but this information was gotten from my sources... If it is not true, then I am sorry...
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#255
by
Chris Bergin
on 03 Mar, 2007 11:31
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3/2/2007 18:05
STS 117 / OV 104 / Pad A
Orbiter powered down
Next power up scheduled for Saturday 09:00
S00024 post ops in work
Payload bay doors open for payload transfer
S00038 in work
RSS retract scheduled for 01:00 Sunday
85217 call to stations is 03:00 Sunday
First motion 07:00 Sunday
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#256
by
nathan.moeller
on 03 Mar, 2007 18:45
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anik - 3/3/2007 1:24 AM
I will answer to the first sentence only and ignore other two...
There will be two spacecrafts on ISS after Soyuz TMA-9 landing: Progress M-59 - on Pirs module and Soyuz TMA-10 - on Zvezda module... Progress M-59 is unprofitable for performing maneuvers of changing ISS orbit... The using of Soyuz TMA-10 engines for such purposes is dangerously...
"If" Space Shuttle will enter very low orbit then, according to agreement between Russian and U.S. specialists, ISS must lower orbit by approximately 100 kilometres... In this situation we can perform such maneuver with using Zvezda's engines only... Therefore Soyuz TMA-10 must be relocated from Zvezda module to Zarya module prior to STS-117 launch...
I am not a specialist, but this information was gotten from my sources... If it is not true, then I am sorry...
Bravo. Anik, I'm not sure if you can answer this one, but you seem to know more about Russian operations than most others on the site. The situation concerning the STS-118 delay and Suni Williams' return seems very open-ended at this point. It seems her stay will be extended indefinitely, as she cannot return on the upcoming Soyuz flight. STS-117 is delayed to April for sure, and it doesn't seem feasible to place Clayton Anderson on that crew and swap Williams out at that point (I could be wrong). With no flights between STS-117 and STS-118, it seems she must stay an extra two months. Are there any other return options available for her at this point?
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#257
by
Chris Bergin
on 03 Mar, 2007 19:56
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Ok, time to move to the new thread...
But SRBs have self-destruct charges that can be detonated by the RSO (Range Safety Officer). The only time that has happened was STS-51L (Challenger Accident). The boosters were destroyed about 37 seconds after the disintegration of Challenger and the ET.