Article by the one and only T.S. Subramanian.Gerard wrote:One GSLV strap-on motor recovered from sea
Another GSLV strap on motor recovered, but unfortunately again, not the one that malfunctioned :
Another strap-on engine recovered
Article by the one and only T.S. Subramanian.Gerard wrote:One GSLV strap-on motor recovered from sea
NEW DELHI: India's longest-range ballistic missile, Agni-III, which failed its maiden test on July 9, has more serious problems than have been reported. Unless rectified and successfully proven, the failed Agni-III test will continue to have serious implications for India's credible minimum deterrence, according to the strategic affairs magazine Force.
"The problem in Agni-III occurred in its first rocket itself after the propellant burnt for about 50 seconds. A top Defence Research and Development Organisation (DRDO) official confirmed this to Force. This implies a design flaw that could happen on many counts. The gimballed nozzles in the first stage of the rocket may not have functioned, there could have been an irregular flow of propellant through the nozzles, and the propellant itself may require an investigation," writes Force Editor Pravin Sawhney in the latest edition of the magazine.
The magazine goes on to point out that the more pertinent thing is that nothing of Agni-III as a whole system has yet been validated including stage separation, re-entry at high temperature, the composite (carbon-carbon) bonded material on the nose cone of the re-entry vehicle as the temperature at re-entering the atmosphere would be much higher than 3,000 degrees centigrade, the stability of the warhead within the payload and the guidance system which is imperfect for long ranges.
Probably, the ground-testing of various systems was not done successfully as otherwise the basic flaw in the design of the first stage of the propulsion system would have been detected. The DRDO had the time to do this task while it waited for the government's go ahead for the test firing.
According to the DRDO source, it would take upto eight months to a year for detecting flaws and producing a fresh prototype for test firing. It will require a minimum of three to four tests in rapid succession to validate a weapon system before its design is sealed for production.
The 'Hindu' article makes for strange reading. The headline asserts that a design flaw is/was the cause when in reality it is only a speculative assessment from a magazine editor. The headline is mentioned in quotes as if some one made that statement, but no one made that assertion, not even PS. Per comment 'This implies that......', note the smooth segue from a single comment (by an anonymous DRDO man) to the unbridled speculation/guessing by PS, liberally peppered with the coulda's/mebbe's etc. I suppose PS has the freedom to speculate, but tone of the report in Hindu (Sandeep Dikshit) morphs uncertainity into fact. I suppose there is not much else one can contribute if you are writing a report on a report....RaviBg wrote:"Design flaw behind Agni-III failure"
NEW DELHI: India's longest-range ballistic missile, Agni-III, which failed its maiden test on July 9, has more serious problems than have been reported............
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"The problem in Agni-III occurred in its first rocket itself after the propellant burnt for about 50 seconds. A top Defence Research and Development Organisation (DRDO) official confirmed this to Force. This implies a design flaw that could happen on many counts. The gimballed nozzles in the first stage of the rocket may not have functioned, there could have been an irregular flow of propellant through the nozzles, and the propellant itself may require an investigation," writes Force Editor Pravin Sawhney in the latest edition of the magazine.
Been wondering about that myself....how much ground-testing could have been done, and how much was done.Probably, the ground-testing of various systems was not done successfully as otherwise the basic flaw in the design of the first stage of the propulsion system would have been detected.
If true, that is a bit strange. One would think that thorough testing would have been done (as dxchen said), which would help work out many of the fundamental design issues, to not do so is almost unbelievable.Arun_S wrote:
The maiden Agni-III has many serious design flaws
I think the propellent composition was same as before and what they are saying is it needs more specific impulse to account for the increased weight of F/S. That is more energetic propellent might be required. The second charge of airflow could be to ensure no re-entrant flow at high speed.....there could have been an irregular flow of propellant through the nozzles, and the propellant itself may require an investigation
Anyone, Is Agni III Liquid fuelledRaviBg wrote:"Design flaw behind Agni-III failure"
I think A3 uses flex nozzles and not engine gimbal... For second stage control Flex nozzles have also been used in A2 from 4th test (1994) onwards.. the first 3tests used engine gimbal control for second stage bcoz 2nd stage was liquid-fuelled (Prithvi)arun wrote:Anyone, Is Agni III Liquid fuelledRaviBg wrote:"Design flaw behind Agni-III failure"
I ask as I think "gimballed nozzles" and "flow", terms used in the quoted Force article, are associated only with Liquid propulsion systems.
Would that be barking up the wrong tree ?
The Indian Space Research Organisation (ISRO) says a malfunctioning engine thrust controller caused the failure of the Geosynchronous Satellite Launch Vehicle (GSLV) on 10 July, but the official report will not be published for another month, writes Radhakrishna Rao.
Don't have to second guess, my views are still available on previous page.ShibaPJ wrote:Breaking News.. GSLV failure tracked to the fuel-control device..
Gurus, can you shed some more light If I recollect correctly (from Arun_S, Ramana & other's posts), probably a software glitch or component design was to blame.
Faulty gadget brought down GSLV
The launch would still be a failure, wouldn't it? I don't think it is possible to rectify such situations mid-flight. Is there a specific reason to call it a design failure? I would rather think, this is a serious QC/QA failure that a faulty component managed to sneak in, as it was not a new design/ usage. or did I miss something else?a well designed control system should have captured this non-catastrophic partial failure scenario and operated the engine in graceful degradation mode, that yields reduced performance rather than take the extreme step to shutdown the engine
They have said that the flawed gadget, on board one of the four strap-on boosters of GSLV F02, let in more propellant than required into the engine, setting off a chain reaction that resulted in erratic propulsion. The thrust generated by this booster did not match that of the other three strap-ons, forcing the rocket off
The chain is as strong as the weakest link. NapoleanBut Nair said the firm, which supplied the faulty propellant regulator, which cost Rs 1 lakh, would not be black-listed and that the space agency will continue to source the component from the same supplier.
If a vendor was blacklisted everytime he made a mistake, there would be no Lockheeds, Boeings, General Dynamics, Raytheons, blah, blah, blah, today....But Nair said the firm, which supplied the faulty propellant regulator, which cost Rs 1 lakh, would not be black-listed and that the space agency will continue to source the component from the same supplier.
quite right.. at the same time, we should have better regulation and inspection regime (just like in the USA where vendors need to be certified something and that thing security type pass etc) that reports on the vendors audit.abhishek wrote:If a vendor was blacklisted everytime he made a mistake, there would be no Lockheeds, Boeings, General Dynamics, Raytheons, blah, blah, blah, today....But Nair said the firm, which supplied the faulty propellant regulator, which cost Rs 1 lakh, would not be black-listed and that the space agency will continue to source the component from the same supplier.
Yes. Many critical rocket parts are non testable since any intensive testing would destroy the part itself. Especially parts associated with propellants. motors and engines. So only Non - destructive testing is applied against these parts and results we see for ourself.SriKumar wrote:I wonder if they were able to determine what specifically was wrong with this part, and why. I think that should be a part of the analysis.
So this part was 'not testable on ground'? This raises the question of what other rocket parts are not testable on ground; and are additional QA checks needed for them. Surely they should be able to devise something to make sure it works before they put it on. 'Testing' them by flying them is expensive, to say the least. I mean, you lose not just the rocket but the payload as well.
Chidambaram as part of an IISc talk some years ago had stated that with unmanned rockets - it is cheaper to test the rocket itself than conduct exhaustive tests of every single part. Some parts cannot be tested until you use them. In this particular case the part was a "known and tested" part and it may have to be retested or QC checked.symontk wrote: Yes. Many critical rocket parts are non testable since any intensive testing would destroy the part itself.
geeth wrote:From the report, it appears that the part failed 0.2 seconds after lift-off. If it had 'failed' within 4 seconds after ignition, the software was supposed to shut off the engine and abort the mission - it would have saved the rocket & payload..