Indian Space Program Discussion

ashokpachori · Post by **ashokpachori** » 30 Dec 2010 13:55

The GSLV was lighter (fuel burn) by almost 90 tones at 48th second, so why blame heavier weight of mere 3 tones to be responsible for fiasco?

As for the cofiguration, would not ISRO have done essential (relevant) calibrations ?

Hence I fail to understand why speculation has taken over on above parameter.

dinesha · Post by **dinesha** » 30 Dec 2010 14:34

One possibility is that:

GLSV-F06 was launched with heavier and longer third stage with additional 4 tonnes of propellant for cryogenic engine. Payload was also heavier by 90 kgs then previous launch. Thus the launch vehicle had ‘heavier head’ by ~4.1 tonnes.

The GSLV performed normally till around 47 seconds burning around 100 tonnes of first stage fuel by that time.. leading to higher asymmetrical loadings at GSLV head and tail.

This seemingly small increase in weight at rocket head along with other transonic flight regime characteristics could have led to increase in ‘moment of momentum’ causing heavy stress in mid-body (2nd-3rd Stage) leading to snapping of connectors and hence loss of vehicle controllability.

This would have aggravated the moment of momentum and the applicable loads ..the resultant higher bending moment and torque would have initiated the collapse of heat shield as well as the joints of strap-on motors... causing catastrophic break-up of the vehicle..

SSSalvi · Post by **SSSalvi** » 30 Dec 2010 15:17

A food for thought :

I would think of following sequence:

The heat shield capsule of the cryo-engine, where the satellite is located, broke first

The fragments of this hit the connector panel/wires emanating from it and this caused the secondary situation:

ten connectors between the second and cryogenic third stage snapped ..got separated, leading to the vehicle losing controllability

& This sudden uncontrolled/loss of torque control

broke the strap-on motors in the first stage.

And so the cool head took appropriate action:

As the vehicle started disintegrating, the mission was destroyed by the Range Safety Officer by pressing the "destruct" button, to prevent the debris from falling in human habitations.

ashokpachori · Post by **ashokpachori** » 30 Dec 2010 15:22

I know for sure that Satellites have screw type connectors

They are (multi) pin type.

ashokpachori · Post by **ashokpachori** » 30 Dec 2010 15:24

The heat shield capsule of the cryo-engine, where the satellite is located, broke first

And the cause of above mishap?

SSridhar · Post by **SSridhar** » 30 Dec 2010 17:23

ramana wrote:Snapping of 10 connectors led to GSLV failiure

...
The heat shield capsule of the cryo-engine, where the satellite is located, broke first followed by the strap-on motors in the first stage.

It was not just the Heat Shield, but the entire stage along with the equipment bay got separated. At least that was how it appeared from the TV grab that was posted before. At least one strap-on motor also could be seen falling off. Obviously, when equipment bay is severed, all control signals are lost.

prithvi · Post by **prithvi** » 30 Dec 2010 18:19

ramana wrote:Well what do we have here!

Snapping of 10 connectors led to GSLV failiure

...
As many as ten connectors between the second and cryogenic third stage had snapped, resulting in non-receipt of commands from onboard computers to strap-on motors in the first stage leading to disintegration of the Geostationary Satellite Launch Vehicle (GSLV-F06) mission which was destroyed within a minute of launch on on Christmas Day.

ISRO sources, speaking on condition of anonymity, said analysis of the data revealed the GSLV-F06, which was meant to put India's heaviest and most advanced communicationsatellite GSAT-5P in orbit, went out of control due to snapping of ten connectors.

"The take-off was smooth and the flight was normal till 47 seconds. But trouble arose in the next three seconds, when 10 connectors located between the second and third stage (cryogenic stage) got separated, leading to the vehicle losing controllability," the sources said.

The heat shield capsule of the cryo-engine, where the satellite is located, broke first followed by the strap-on motors in the first stage.

As the vehicle started disintegrating, the mission was destroyed by the Range Safety Officer by pressing the "destruct" button, to prevent the debris from falling in human habitations.

The sources said they believed that the area near the connectors, which were like mini-plugs and sockets to take the command from on- board computers at the top portion of the vehicle right down to the strap-on in the first stage, would have received sudden heavy loads between the second and third stage, leading to their snapping.

The sources stoutly denied that increase in the weight of the satellite by nearly 100 kg had led to the disaster.

Analysis of the data showed that snapping of connectors had led to the disintegration of the vehicle and it had nothing to do with the increase in the weight of thesatellite, which was only marginal, the sources said.

Progressive failure of heat shield and then the strap ons. So it started from the Cryo stage. Maybe the member who guessed it was the leakage that caused it was right after all.

How does the whole "self destruct" mode work? I understand there is a kill switch and all however do they have some kind of explosives which expedite the process of disintegration at higher altitude? just curious.. also there must be some system imposed constrain to make the switch "inactive" within a certain envelope...?

Victor · Post by **Victor** » 30 Dec 2010 19:52

ashokpachori wrote:
The heat shield capsule of the cryo-engine, where the satellite is located, broke first

And the cause of above mishap?

Most likely the failure of one or more strap-ons as has been stated. This would cause the thurst to be unevenly distributed, which in turn would cause the vertical axis to wobble. External forces would instantly increase on all the stage-separation joints like a massive jolt but would be highest on the topmost stage which would break off first. The connectors that “broke” are most likely a symptom, not a cause. Things don't normally break in unison without a cause. The focus is probably on the strap-ons as the primary event.

SSSalvi · Post by **SSSalvi** » 30 Dec 2010 20:50

An afterthought:

The stages have to be separated ... so there should be some mechanism to 'detach' the male-female parts of connectors from each other during separation.
And this has to be achieved by some sort of electronic 'detach' command.

If multiple connectors have snapped then it could be due to a rogue command impulse issued to their separation mechanism also.

Thinking about a possibility.

================

Regarding Self destruct command:

A colleague who participated in assembly/evaluation of rockets at SHAR had told me that destruct command pulls a thin steel wire that has been woven lengthwise around the rocket passing through nose ( Satellite housing ) and extending upto bottom.
When triggered this wire cuts through the body of rocket and cuts it into two halves though-out the length causing destruction of all the generated torque.

I could not verify the correctness of this from other sources.

SriKumar · Post by **SriKumar** » 30 Dec 2010 20:52

ramana wrote:Well what do we have here!

Snapping of 10 connectors led to GSLV failiure

...
As many as ten connectors between the second and cryogenic third stage had snapped, resulting in non-receipt of commands from onboard computers to strap-on motors in the first stage leading to disintegration of the Geostationary Satellite Launch Vehicle (GSLV-F06) mission which was destroyed within a minute of launch on on Christmas Day.

ISRO sources, speaking on condition of anonymity, said analysis of the data revealed the GSLV-F06, which was meant to put India's heaviest and most advanced communicationsatellite GSAT-5P in orbit, went out of control due to snapping of ten connectors.

"The take-off was smooth and the flight was normal till 47 seconds. But trouble arose in the next three seconds, when 10 connectors located between the second and third stage (cryogenic stage) got separated, leading to the vehicle losing controllability," the sources said.

The above article points to failure of connectors as the primary cause (i.e. leading to other failures before self-desctruct). Here are some pictures of previous GSLVs from ISRO website where one can see the outside of the rocket. (There's one level of magnification in the pix.)

GSLV F04
http://www.isro.org/gslv-f04/photos/Enc ... 0stage.JPG
http://www.isro.org/gslv-f04/photos/Vie ... ilding.JPG
http://www.isro.org/gslv-f04/photos/GSL ... ge%202.JPG

GSLV D3
http://www.isro.org/gslv-d3/Imagegaller ... cle.aspx#1
http://www.isro.org/gslv-d3/Imagegaller ... cle.aspx#2

ashokpachori · Post by **ashokpachori** » 30 Dec 2010 21:53

prithvi wrote: How does the whole "self destruct" mode work? I understand there is a kill switch and all however do they have some kind of explosives which expedite the process of disintegration at higher altitude? just curious.. also there must be some system imposed constrain to make the switch "inactive" within a certain envelope...?

Here is some from Popular mechanics:

If the spaceship were to veer off course and endanger a populated area, this range safety officer would bear the terrible responsibility of flipping a pair of switches under a stenciled panel reading "Flight Termination." The first switch arms explosives on the shuttle's two solid rocket boosters. Flipping the second switch would detonate them

http://www.popularmechanics.com/science ... sa/4262479

The U.S. space shuttle orbiter does not have destruct devices, but the solid rocket boosters (SRBs) do

ashokpachori · Post by **ashokpachori** » 30 Dec 2010 22:35

Chennai, Dec 30 (IANS) Former chairman of Indian Space Research Organisation (ISRO) G. Madhavan Nair will be guiding the various teams set up to study data and identify the cause of the Christmas Day failure of the agency's rocket.

'I will be guiding the various teams that are studying the flight data of the GSLV (geosynchronous satellite launch vehicle) rocket to arrive at the cause of failure,' Nair told IANS.

http://www.sify.com/news/indian-space-a ... fheej.html

ashokpachori · Post by **ashokpachori** » 30 Dec 2010 22:39

S Satish, ISRO’s director for public relations and spokesman, said the space organisation currently has 164 transponders and leases 67 from other satellites.

“Meanwhile, we are getting ready to launch another satellite sometime around March and April in 2011, which will carry 24 Ku band transponders.

ashokpachori · Post by **ashokpachori** » 30 Dec 2010 23:23

Probe should detail reasons by weekend, says Isro

Allegations and accusations are said to be flying between the three divisions of Isro, according to sources.

"We know what happened and when it happened. We are trying to find out why it happened," he added.

It is being speculated that the snapping of connectors between the second and third stage of the Indian rocket GSLV might have led to the failure, according to a scientist. But, it's mere speculation, added the spokesperson. He said in a day or two, Isro would come out with reasons for the mishap.

The three divisions involved in the project — the Isro Satellite Centre (ISAC) in Bangalore, Vikram Sarabhai Space Centre (VSSC) in Thiruvananthapuram and the Satish Dhawan Space Centre (Shar) at Sriharikota — had been pointing fingers at each other. Was the payload the problem or the design and manufacturing or the assembly? The inquiry is now trying to figure if the problem occurred at the ISAC, where the satellite was assembled, or at the VSSC, where the rockets are made or at the Shar, where the whole GSLV, the launch vehicle, was assembled with the satellite.

According to a retired Isro official in the know of things, the scientists were sceptical from the beginning about the launch. The capacity of the third stage of the GSLV had been increased to be able to launch a heavier satellite. A team of Russian engineers are said to have come here to help raise the capacity of the launch vehicle.

http://www.business-standard.com/india/ ... re/420106/

ramana · Post by **ramana** » 31 Dec 2010 03:52

S^3, Separation connectors are spring loaded and the pull away force as the stages move away is sufficient to have them separated. Its not much per connector.

The connectors are round and have pin and sockets and pull apart with a given force.

Kanson · Post by **Kanson** » 31 Dec 2010 10:59

Is there a possibility of stuxnet type sabotage? Where the virus generating wrong signals to increase the dynamic load or such things ?

Arya Sumantra · Post by **Arya Sumantra** » 31 Dec 2010 12:32

^^^ I was thinking about Stuxnet as well.

Kanson · Post by **Kanson** » 31 Dec 2010 15:25

^ Lately, I'm entertaining such thoughts. I think that is definitely possible. And i have my reasons.

While one stream of thought accused Israel/US and Israel/Germany/France for Stuxnet Cyberwar, others also thought about China angle and they bring their reason to support that theory.

India and China are in undeclared and unofficial race which China assumes that as competition to its status as the sole Czar of Asia. This desire/ambition was expressed by China in different times and different ways, the last one we heard was when Obama visited China. This is a known secret to all.

India thou' is not in for such status as it believe in multi-polarism concept, it wants to show sometimes its independent ascendancy to thwart such over lordship attitude from China. When we announced to the world about our ABM programme, China tested ASAT and stole the thunder. When China sent lunar satellite, we stole the thunder back with the discovery of water with our Chandrayaan probe. We plant our Indian Flag in moon before Chinese could do and the paranoid Chinese did or planned something of such sorts later. Our announced future Chandrayaan goals were seen as much aggressive or atleast equal to China's Lunar program. Success of Chandrayaan led China to modify their own Lunar program schedule. While China started trumpeting to the world and to their citizens about their ASBM, we coolly let out that our Dhanush BM is an anti-ship weapon(implying we have already done that) and our missile program is much advanced. This type of tit for tat race was there albeit in low intensity from previous decades.

Its well known that US and USSR locked horns in Space arena to show who is winning the race and who is more advanced. Japan did that when it was at its peak.

I believe China is already taken that path. Those two standing on the path of its glory which will deny its ascendancy as the most advanced nation in the world is US and in Asia is India. India's shoulder to shoulder and toe to toe future space programs to that of China, has removed the sheen of China's success. If India succeeds, all those poor nations will not flock to Chinese. Already Gulf countries are leaning towards India and that space was once shared only by China and Japan from Asian angle.

The vehicle that denies China as the sole space power is GSLV which is scheduled to carry Chandrayaan.

The two accidents of GSLV and the cryo stage. The early demise of Chandrayaan. I think we need to view this from fresh angle of sabotage. And we also lost W2M satellite immediately after putting in orbit. It is not only me, ISRO people too are thinking in this angle of sabotage to safeguard our program against such savages, I hope.

Pratyush · Post by **Pratyush** » 31 Dec 2010 15:42

It is good to be paraniod, it keeps people on their toes. But Space and latalite launch vehicle is such an arena that a million things could go wrong and they usually do go wrong.

The paranoia though healthy should be directed inwards towards the safety and quality control. Even inspite of best practices things will go wrong. The rockets will fail, the satalites will die.

We should learn to take these in our stride and strive to prevent the repeat of the same failures. By drawing appropriate lessons from them.

As long as we are doing so, we will keep on moving forward, inspite of painfull setbacks.

Kanson · Post by **Kanson** » 31 Dec 2010 15:54

^ Failure of Chandrayaan is attributed to foreign component in power supply unit, iirc.

Pratyush · Post by **Pratyush** » 31 Dec 2010 16:01

^^^ and it means?

1) Sabotage.
2) Inadequate testing.
3) Poor integeration.
4) Poor QC.
5) All the above.
6) None of the above.

If that's the reason, then why did it happen?

What lessons were lernet by ISRO?

Thes are the most valuable questions to answer.

Kanson · Post by **Kanson** » 31 Dec 2010 16:19

^ Its very nice to ask Q's, opinions are formed after going throu lot of understanding, deliberations and of course reading...just go throu' this for a start...and you can too have your own opinion.
http://www.deccanherald.com/content/807 ... -loss.html

Pratyush · Post by **Pratyush** » 31 Dec 2010 16:30

K,

Thanks for the link, I am afread that I am too Ignorent of the space business to form an opinion which will carry any weight. I will always have questions. And seek to learn from the answeres that I Recieve / Find.

Having said so, from the artilce I conclude that the imported item thought needed by the ISRO was of substandard quality which failed prematurely. The fault to the extent rests with the ISRO, for not being able to disern the quality of the component in question before integerating the same in the satalite.

Secondly, the domestic industies inability to come up with the required item of sufficient quality / Size / weight is a matter of concern.

ashokpachori · Post by **ashokpachori** » 31 Dec 2010 16:51

Everybody was talking about cryo leak, but it seems like it was NOT. It was helium though.

Indian Space Research Organization (ISRO) sources tell Aviation Week that the decision was made after a helium gas leak was detected from one of the valves in the vehicle’s upper cryogenic stage. “We observed the leak in the Russian cryogenic engine during the pre-countdown check,” says an ISRO official at the launch site in Sriharikota. “We had no option but to call it off as the leak was very huge.”

http://www.aviationweek.com/aw/generic/ ... /21/02.xml

So the fuel never leaked!

Varoon Shekhar · Post by **Varoon Shekhar** » 31 Dec 2010 19:29

"India and China are in undeclared and unofficial race which China assumes that as competition to its status as the sole Czar of Asia."

Very good, Kanson. Your list of the sequence of China's responses to India, is quite astute. If you look at the history of this 'competition' between India and China in the last 60 years, there is almost not a single industry or service, science or technology, sport( not even Table tennis) or entertainment/art, where India followed China. Except for nuclear bombs and missiles, which gives you an idea of the character of China. Even in the nuclear field, it was only in bombs where China led India, not in power reactors or other aspects of nuclear technology. And the amazing thing , is that none of India's behaviour has anything to do with India wanting to be the 'czar' of Asia; India desires multi-polarity as you have observed.

India must get its GSLV mark 2 up and running, and accelerate the GSLV mark 3 programme. Do you think there's a chance of the Mark 3 vehicle overtaking the Mark 2, since these are( presumably) separate programmes with different teams on them?

prao · Post by **prao** » 31 Dec 2010 21:21

SSSalvi wrote:An afterthought:

...
If multiple connectors have snapped then it could be due to a rogue command impulse issued to their separation mechanism also.

...
Regarding Self destruct command:

A colleague who participated in assembly/evaluation of rockets at SHAR had told me that destruct command pulls a thin steel wire that has been woven lengthwise around the rocket passing through nose ( Satellite housing ) and extending upto bottom.
When triggered this wire cuts through the body of rocket and cuts it into two halves though-out the length causing destruction of all the generated torque.

I could not verify the correctness of this from other sources.

That colleague might have mis-spoken I suspect. The stitching of the two halves in the nose is the mechanism to discard the payload fairing of the rocket after ascent when air resistance is negligible. A pyro mechanism destroys the stitching and springs push the two halves of the fairing apart and off the path of the rocket. There are several papers by ISRO folks about this.

Another possible reason for the failure is that the increased weight caused longitudinal vibrations in the rocket (brief explanation: change in weight and structure changes the modes shapes and frequencies and how the engines/aero forces excite them. This is always analyzed before launch and adequate precautions taken i.e make sure that the structural frequencies are not excited by the engines/aero forces. That analysis could have missed some interaction) The vibrations could have torn apart the connectors even if they did not result in structural failure. My money is currently on this explanation rather than a rogue command as you suggest simply because the software would have been tested but the structure was new.

ramana · Post by **ramana** » 31 Dec 2010 21:48

usually there are three types of destruct on a vehicle.

- Command Destruct. This blows up the vehicle on commnad by range safety.
- Auto Destruct. The vehcile blows up when it senses unanticipated accelerations, position etc indicating out of programmed trajectory.
- Self Destruct. The vehicle has breakwire or some other positive mechanism that breaks and causes it to blow up. This feature is when there are sudden loads which cause vehicle breakup.

Kanson, There is a theory that US manages the rise of India such that PRC doesn't get too antsy and develop systems in response which have negative impact on US. Per that theory the US works thru its agents under influence to work to make it feasible. A2P cannisterisation was such a development that would have such a sequence of events. Noe these AUIs need not take funds as long as they think like that.

SaiK · Post by **SaiK** » 31 Dec 2010 21:59

Pratyush wrote:^^^ and it means?

imho, the answer is 5.

ramana · Post by **ramana** » 31 Dec 2010 22:35

Economic Times reports:

iSRO Forms Eminent Panels to Study Failure and look at future

BANGALORE: ISRO has constituted a committee to probe the unsuccessful GSLV-F06 mission and a panel to look into the future of the GSLV Programme and assured launch of satellites, operationalisation of indigenous cryogenic stage and strategy for meeting communication transponder needs.

ISRO Chairman K Radhakrishnan has formed a Failure Analysis Committee (FAC) to carry out an in-depth analysis of the flight data of GSLV-F06 as well as the data from the previous six flights of GSLV, establish reasons for the flight's failure and recommend corrective actions on the GSLV vehicle including the remaining one Russian Cryogenic Stage.

"The Failure Analysis Committee chaired by former Chairman ISRO Dr G Madhavan Nair has 11 Experts drawn from within ISRO and outside," Bangalore-headquartered Indian Space Research Organisation said in a statement today.

The ISRO Chairman has also constituted a Programme Review and Strategy Committee to look into the future of the GSLV Programme and assured launch for INSAT/GSAT Series, INSAT-3D as well as Chandrayaan-2; realisation and operationalisation of indigenous Cryogenic Stage and strategy for meeting the demands of communication transponders in the immediate future.

Dr K Kasturirangan, former Chairman of ISRO and presently Member of the Planning Commission, would be chairing this seven member Committee.

These two Committees have been requested to submit their reports by January-end. Subsequently, the reports of these Committees would be presented to eminent national experts including Dr A P J Abdul Kalam , Prof. M G K Menon , Prof. Yash Pal, Prof. U R Rao, Dr K Kasturirangan, Dr. G Madhavan Nair, Dr R Chidambaram, and Prof. R Narasimha.

Further, a panel chaired by Dr S C Gupta, former member of Space Commission, would be guiding and facilitating an internal exercise by Chairman, ISRO, eliciting views from the ISRO community at all levels to gear up for the complex and challenging space missions ahead.

ISRO said it plans to complete these reviews and internal exercises by February end.

On the failed mission last week, ISRO said the performance of the GSLV-F06 flight of December 25 (with GSAT-5P Satellite onboard) was normal up to 47.5 seconds from lift-off.

The events leading to the failure got initiated at 47.8 seconds after lift-off. Soon, the vehicle started developing larger errors in its orientation leading to build-up of higher angle of attack and higherstructural loads and consequently vehicle broke up at 53.8 seconds from lift-off (as seen visually as well as from the Radars).

Non Sequitor:

Its heartening to see the composition of the eminent panels and how well versed they are in the subject. Also happy to note the members are represented.

Gagan · Post by **Gagan** » 01 Jan 2011 03:34

Pratyush wrote:1) Sabotage.
2) Inadequate testing.
3) Poor integeration.
4) Poor QC.
5) All the above.
6) None of the above.

My opinion:
3) leading to 4)

A chain is only as strong as its weakest link, and a multistage rocket is only as weak as the weakest point, in this case the ?Rocket Boosters coming off, ?Control cables snapping, ?Links between the stages buckling.

One small thing failed and the whole mission was compromised.

Sabotage and Virus are things that organizations such as the ISRO are aware and very sensitive about. I would very much doubt either of them to be responsible.

ramana · Post by **ramana** » 01 Jan 2011 06:50

Hate to be right but they were the separation/staging connectors. My next guess will be the staging connector bracket broke due to cryo embrittlement.

Snapping of connectors caused GSLV failure:ISRO

Snapping of connectors caused GSLV failure: ISRO

Staff Reporter

Programme Review and Strategy Committee set up to look into the future of the programme

The precise cause of the snapping of conductors is to be analysed further

Failure analysis panel will recommend corrective action on GSLV vehicle

BANGALORE: A Preliminary Failure Analysis Team constituted to study the flight data of GSLV-F06, which crashed seconds after its launch on December 25, said that the primary cause of the failure was “the untimely and inadvertent” snapping of a group of 10 connectors located at the base of the Russian Cryogenic stage.

The premature snapping of these connectors stopped the flow of control commands to the core First Stage control electronics, leading to the loss of control and breakup of the vehicle, said a press statement from the Indian Space Research Organisation (ISRO) on Friday. The precise cause of the snapping of this set of connectors — whether due to external forces such as vibration or dynamic pressure — is to be analysed further, the statement added.

Command signals

Some of these connectors carried command signals from the onboard computer located in the Equipment Bay (near the top of the vehicle) to the control electronics of the four L40 strap-ons of the First Stage. These connectors were intended to be separated only during a separation command at 292 seconds after lift-off.

The performance of the GSLV-F06 flight (with GSAT-5P Satellite onboard) was normal up to 47.5 seconds from lift-off. The events leading to the failure began at 47.8 seconds after lift-off. Soon, the vehicle started developing “larger errors” in its orientation “leading to build-up of higher angle of attack and higher structural loads,” according to ISRO. The vehicle broke up at 53.8 seconds from lift-off. A “destruct” command was issued from the ground at 64 seconds after lift-off as per the Range safety norms.

The Preliminary Failure Analysis Team was chaired by the former ISRO Chairman, G. Madhavan Nair, and analysed the flight data along with members of the Launch Authorisation Board, the Mission Readiness Review Committee as well as senior functionaries of the GSLV Project and experts.

The ISRO has now constituted a Failure Analysis Committee to carry out an in-depth analysis of the flight data of GSLV-F06 and data from the previous six flights of GSLV. The committee will establish reasons for the failure of GSLV-F06 and recommend corrective actions on the GSLV vehicle, including the remaining solitary Russian Cryogenic engine. The Failure Analysis Committee has 11 experts drawn from within ISRO and outside.

The ISRO has also constituted a Programme Review and Strategy Committee to look into the future of the GSLV Programme and the launches of the INSAT/GSAT Series, INSAT-3D and Chandrayaan-2. It will work towards the operationalisation of the indigenous Cryogenic Stage and come up with a strategy for meeting the demands of communication transponders in the immediate future, the statement said. This seven-member committee will be headed by K. Kasturirangan, former ISRO chairman.

These two Committees have been requested to submit their reports by the end of January 2011. The reports will be presented to eminent scientists and engineers, including A.P.J. Abdul Kalam, M.G.K. Menon, Yash Pal, U.R. Rao, K. Kasturirangan, Mr. Madhavan Nair, R. Chidambaram, and R. Narasimha.

“Internal exercise”

A panel chaired by S.C. Gupta, former member of Space Commission, will guide and facilitate an “internal exercise” by the ISRO chairman, and elicit “views from the ISRO community at all levels to gear up for the complex and challenging space missions ahead.”

The ISRO plans to complete these reviews and internal exercises by end of February 2011.\

So the breaking of the staging connectors was a secondary error. The true root cause is the development of large attitude errors after 47.8 secs which caused increased structural loads. And these loads caused the bracket to break and caused the connectors to come apart. Usually the force required to separate them is quite low of the order of 100 lbs.

So why did the vehicle develop those large attitude errors?

I think vina had said that it was attitude errors caused loads had resulted in the vehicle failure as soon as it was reported.

juvva · Post by **juvva** » 01 Jan 2011 09:44

^

ISRO;s preliminary report: http://isro.gov.in/pressrelease/scripts ... Dec31_2010

"
.......
.......
The finding of the Preliminary Failure Analysis Team is that the primary cause of the failure is the untimely and inadvertent snapping of a group of 10 connectors located at the bottom portion of the Russian Cryogenic Stage.
.......
.......
"
As per the above press release the the primary cause is snapping of the connectors, loss of control and attitude errors were the effect not the cause.

Edited later: to correct the url for ISRO's preliminary report.

Bade · Post by **Bade** » 01 Jan 2011 09:55

The cause effect direction should be easy enough to debug, right. If telemetry data shows attitude errors growing and the control signals transmitted for correction, which means connectors were still intact and were destroyed along with rest of the rocket.

If no such trace is found in the telemetry data, then it means connectors were snapped already before attitude errors grew out of the safety envelope, and left no recourse for correction leading to stress and partial break up (?) or veering way of course which initiated mission destruction.

vina · Post by **vina** » 01 Jan 2011 10:36

I think vina had said that it was attitude errors caused loads had resulted in the vehicle failure as soon as it was reported.

Like I said earlier, I think it is primarily a loss of control problem, basically some IT/Vity problem either hardware or software.

I think the way it happened is this.

1) Loss of control. From the reports coming in, some IT/Vity failure (connectors snapping /etc..etc..) that led to loss of electrical contact between the Kampooter and the gimbal activation systems in the 4 strap on Vikas engines.

2) No control commands transmitted--> Effectively vehicle uncontrolled and vehicle is doomed right here.

3) Uncontrolled vehicle started losing attitude orientation and AoA started building up

4) As AoA increased, structural loads went beyond design limits leading to collapse of the heat shield/payload fairing (you can see that crumple and fly off definitely, along with parts of the satellite maybe)

5) Vehicle starts to break up and the range safety destroys it by pressing the button.

Now obviously you need to root cause analysis of why No 1) ie loss of control happened. If it is some IT/Vity problem because those guys ignored vibration and other issues in the wiring system design, but just put the Kampooter and command module on a shaker plate and did some shake and vibration tests, you know what to do with those overpaid and spoiled Honda Civic driving DOO (d)s living in places like Indira Nagar and Koramanagala .

Send them to the secret Gulag no 1570 in Siberia ,a purgatory where they will be "vibrated" violently for 2 hrs every day and then they can contemplate deeply and indulge in "self criticism " and then after 3 years of hard labor and reflection can be rehabilated into civil society

! That is the way Chailman Meow and Stalin and Beria would have dealt with them. Didn't Korolev "purged" at first?

juvva · Post by **juvva** » 01 Jan 2011 11:43

The preliminary report says:
"
....
.....
These connectors are intended to be separated only on issue of a separation command at 292 seconds after lift-off.
.....
......
"

We could be looking at a software error: issue of connector separation command way too early in the flight profile. Though it is difficult to imagine why the software would be tweaked to that extent for this version/configuration of the vehicle.

ramana · Post by **ramana** » 01 Jan 2011 22:22

For effective corrective action true root cause has to be found. A true root cause is one which we cant ask anymore questions.
So snapping connectors is an effect and not a cause.

SriKumar · Post by **SriKumar** » 01 Jan 2011 23:04

Bade wrote:The cause effect direction should be easy enough to debug, right. If telemetry data shows attitude errors growing and the control signals transmitted for correction, which means connectors were still intact and were destroyed along with rest of the rocket.

Exactly. It is easy for them to know whether the connectors snapped first (marked by a loss of signal) or did the attitude errors occur first. That they did not release this data point is intriguing. They must also have the vibration data for the vehicle during the critical timeperiod.

In the time-line released by the Committe, they say (per Hindu):
The performance of the GSLV-F06 flight (with GSAT-5P Satellite onboard) was normal up to 47.5 seconds from lift-off. The events leading to the failure began at 47.8 seconds after lift-off. Soon, the vehicle started developing “larger errors” in its orientation “leading to build-up of higher angle of attack and higher structural loads,” according to ISRO. The vehicle broke up at 53.8 seconds from lift-off. A “destruct” command was issued from the ground at 64 seconds after lift-off as per the Range safety norms.

They dont say anything about i) what these events were at 47.8 seconds, and ii) at what timepoint did the connectors fail (i.e. at or after 47.8 seconds).

Does anyone know if these connectors sit inside the rocket skin or outside? Would they be visible on the outside?

Juvva,
Regarding the issue of the connectors separating at 292 seconds by default, the report says that the connectors 'snapped' and not 'separated'. Maybe I am reading too much into it but this seems to indicate that this was not a graceful separation initiated by any (incorrect) signal.

SaiK · Post by **SaiK** » 02 Jan 2011 09:04

Or was it the connector could not break in time hence the higher angle of attack?

sanjeevji · Post by **sanjeevji** » 02 Jan 2011 10:19

Was there only ONE set of connectors going to first stage? No redundency built into the system, No duplicate control paths?

Bade · Post by **Bade** » 02 Jan 2011 10:45

Not to smear ISRO's efforts but a serious overhaul of the QA/QC processes should be in place. There have been too frequent failures, partial ones or a complete launch failure recently. All these high power committee chai biscuit sessions are not going to amount to anything otherwise. They are not bound to disclose anything other than to a parliamentary committee if at all, but they need to fix all QA issues before dreaming of manned flights at least.