FAILURE: GSLV - GSAT-5P - December 25, 2010

[edkyle99]

http://ibnlive.in.com/news/gslv-failed-as-germanmade-connectors-snapped/139522-11.html

The "snapped" connectors were German-made, for whatever that is worth. 

Note that this report says that even the "backup" connectors "snapped".

I'm an electrical engineer, but I am still completely baffled as to what the term "snapped" means when used to describe connectors.   

 - Ed Kyle 

[robertross]

http://ibnlive.in.com/news/gslv-failed-as-germanmade-connectors-snapped/139522-11.html

The "snapped" connectors were German-made, for whatever that is worth. 

Note that this report says that even the "backup" connectors "snapped".

I'm an electrical engineer, but I am still completely baffled as to what the term "snapped" means when used to describe connectors.   

 - Ed Kyle 

Yeah, it's more likely the improper use of the term. Perhaps a 'case fracture', or 'premature separation event' (since these would likely be break-away connectors designed to separate at a specific pulling force).

If I were to put money on it, without even knowing the full depth of the issue, I'd say connectors were not properly spec'd (or applied) for the vehicle, given the cryo conditions & vehicle's acceleration environment.

[edkyle99]

http://ibnlive.in.com/news/gslv-failed-as-germanmade-connectors-snapped/139522-11.html

The "snapped" connectors were German-made, for whatever that is worth. 

Note that this report says that even the "backup" connectors "snapped".

I'm an electrical engineer, but I am still completely baffled as to what the term "snapped" means when used to describe connectors.   

 - Ed Kyle 

Yeah, it's more likely the improper use of the term. Perhaps a 'case fracture', or 'premature separation event' (since these would likely be break-away connectors designed to separate at a specific pulling force).

If I were to put money on it, without even knowing the full depth of the issue, I'd say connectors were not properly spec'd (or applied) for the vehicle, given the cryo conditions & vehicle's acceleration environment.

My guess would be premature "separation", although I don't know how anyone could say for certain that the cables separated *at* the connectors (unless there was on-board video).  I suppose it might be a good conjecture to make if the symptoms indicated that *all* electrical connections suddenly opened at the same instant. 

Aren't "cable cutters" often used for separating electrical connections during staging?  Not always though.  I've recently read about a failed Atlas booster package electrical separation event where a connector was supposed to be pulled apart by a lanyard as the booster fell away (the lanyard failed on that one, causing a bad separation that must have messed up the booster separation event signal, leading to loss of flight control).

 - Ed Kyle

[Art LeBrun]

A story needing more details: AC-33 suffered an electrical event at staging that, of all things, lead to Centaur ignition while under sustainer flight. I would like to find the accident report and any films (night shot but I don't know the cloud conditions).

[pradeep]

http://ibnlive.in.com/news/gslv-failed-as-germanmade-connectors-snapped/139522-11.html

The "snapped" connectors were German-made, for whatever that is worth. 

Note that this report says that even the "backup" connectors "snapped".

I'm an electrical engineer, but I am still completely baffled as to what the term "snapped" means when used to describe connectors.   

 - Ed Kyle 

Yeah, it's more likely the improper use of the term. Perhaps a 'case fracture', or 'premature separation event' (since these would likely be break-away connectors designed to separate at a specific pulling force).

If I were to put money on it, without even knowing the full depth of the issue, I'd say connectors were not properly spec'd (or applied) for the vehicle, given the cryo conditions & vehicle's acceleration environment.

My guess would be premature "separation", although I don't know how anyone could say for certain that the cables separated *at* the connectors (unless there was on-board video).  I suppose it might be a good conjecture to make if the symptoms indicated that *all* electrical connections suddenly opened at the same instant. 

Aren't "cable cutters" often used for separating electrical connections during staging?  Not always though.  I've recently read about a failed Atlas booster package electrical separation event where a connector was supposed to be pulled apart by a lanyard as the booster fell away (the lanyard failed on that one, causing a bad separation that must have messed up the booster separation event signal, leading to loss of flight control).

 - Ed Kyle

I think they mean "disconnect" here when they say snapped. That is generally the way a lay Indian person in Mumbai would describe it when we have electrical complaints. I am not so sure of other places in India. I guess ISRO scientists wanted to use local layman terms while saying this to ensure people here understood.

I also hope they're not trying to blame foreign components here because whatever the source of the component - Indian or foreign - it was their duty to check whether the system worked. Quality check and assurance is the purchaser's responsibility. I think it is more the media waiting for every tid bit of information and bloating the quote out of all context.

[Jim]

http://ibnlive.in.com/news/gslv-failed-as-germanmade-connectors-snapped/139522-11.html

The "snapped" connectors were German-made, for whatever that is worth. 

Deutsch connectors are used extensively in Delta and Atlas

[asdert]

http://ibnlive.in.com/news/gslv-failed-as-germanmade-connectors-snapped/139522-11.html

The "snapped" connectors were German-made, for whatever that is worth. 

Deutsch connectors are used extensively in Delta and Atlas

But Deutsch connectors are not from Germany. Deutsch is a US connector company.

(edit for typo)

[robertross]

http://ibnlive.in.com/news/gslv-failed-as-germanmade-connectors-snapped/139522-11.html

The "snapped" connectors were German-made, for whatever that is worth. 

Deutsch connectors are used extensively in Delta and Atlas

But Deutsch connectors are not from Germany. Deutsch is a US connector company.

(edit for typo)

With manufacturing facilities around the world.

Not sure if this is the EXACT connector used, but it's probably close:
http://www.deutsch.net/deutsch-product-search.aspx?page=3

I've used various types of Deutsch for years and NEVER had a problem with their quality. Obviously not space-designed components, but the company is very reputable.

As Jim stated: they use them on Atlas & Delta. Need one say more?

[sanman]

I think they mean "disconnect" here when they say snapped. That is generally the way a lay Indian person in Mumbai would describe it when we have electrical complaints. I am not so sure of other places in India. I guess ISRO scientists wanted to use local layman terms while saying this to ensure people here understood.

I also hope they're not trying to blame foreign components here because whatever the source of the component - Indian or foreign - it was their duty to check whether the system worked. Quality check and assurance is the purchaser's responsibility. I think it is more the media waiting for every tid bit of information and bloating the quote out of all context.

Well, first of all, I think he was just casually responding to a query on who made the connectors, and not actually assigning blame to them. After all, for 10 connectors to fail simultaneously sounds like there was some underlying cause (eg. premature state separation)

The thing here is that the media are hungry for even the slightest new tidbit of news on this failed launch, and so even the smallest innocent remark seems to get magnified through headlines.

[seshagirib]

It is not clear (to me) if the connectors get separated because of the stage moving away (stage separation ) - that is pulled apart as the stages move away from each other OR there is some other explicit mechanism for de-mating the connector pairs, prior to the stages moving away.
Could anyone in the know clarify?

[Jim]

It is not clear (to me) if the connectors get separated because of the stage moving away (stage separation ) - that is pulled apart as the stages move away from each other OR there is some other explicit mechanism for de-mating the connector pairs, prior to the stages moving away.
Could anyone in the know clarify?

the first method.

[seshagirib]

Don't see how they can launch anything - PSLV or GSLV without sorting out this failure completely.

 Same/Similar connectors and separation mechanisms  may  be shared across the family of launch vehicles(?).

[input~2]

New information from ISRO on why, potentially, the connectors snapped:
http://www.sify.com/news/rocket-failure-isro-awaits-data-from-russia-news-national-lb2qugdhiab.html

[seshagirib]

New information from ISRO on why, potentially, the connectors snapped:

The German made connectors are fixed on a metal plate. The plate,  in  turn, is fixed to a shroud or cylindrical cover that comes between the  cryogenic engine and the lower stage (engine).   
 According to Nair, the shroud made of composites is part of the Russian  cryogenic engine and it got deformed due to the flight load. The  committee is yet to conclude why the shroud was not able to bear the  load.

from: http://www.sify.com/news/rocket-failure-isro-awaits-data-from-russia-news-national-lb2qugdhiab.html

How did they come to the conclusion that the shroud deformed?

[isro-watch]

So now it is clear that the problem was with cryogenic engine and not with the first stage

also, may be something to do with weight coupled by other factors.


http://mangalorean.com/news.php?newstype=local&newsid=219009

[input~2]

http://www.dnaindia.com/india/report_no-major-design-flaw-in-failed-gslv-f06-ex-isro-chief_1503933

[Shams]

Rocket failure: Russian, Indian scientists differ on cause

The Russians have pointed their fingers at the rocket's bigger heat shield (4 metre) as the proximate cause for high atmospheric load on the rocket that broke it. Refuting that theory, Indian officials cited an earlier GSLV rocket that went up with a heat shield of similar size.



http://economictimes.indiatimes.com/news/politics/nation/rocket-failure-russian-indian-scientists-differ-on-cause/articleshow/7546540.cms

[sanman]

Flawed Shroud Design the Cause of GSLV Failure:

http://timesofindia.indiatimes.com/articleshow/8032380.cms

[Danderman]

"A successful flight of the GSLV is not an impossibility."

Truly inspiring.

[Salo]

http://www.deccanchronicle.com/node/23871