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

[input~2]

I just heard Mr. Radhakrishnan in his conference saying that everything was nominal up to 50s, then [...] higher envelope angle than nominal...leading to high structural loads that led to the destruction ..

[lnb15k]

This was the final picture showing the telemetry. RAN 2.7kms means what? It is 2.7kms from the launch pad? It was the first stage fell there?

[tonthomas]

The flight computer lost communication with the actuators in the liquid fueled strap ons, and the vehicle left its planned path, I unterstood.

Sad day for ISRO.

Thomas

[ugordan]

RAN 2.7kms means what? It is 2.7kms from the launch pad? It was the first stage fell there?

Probably short for range i.e. downrange distance from the pad.

[ugordan]

The flight computer lost communication with the actuators in the liquid fueled strap ons, and the vehicle left its planned path, I unterstood.

Sad day for ISRO.

In some respects this was similar to South Korea's KSLV back-to-back failures. First a problem with the subsequent stage with a good first stage and then on the very next launch a disaster even earlier in the flight.

Must be really demoralizing for the engineers in both cases - feels like you're not making progress but actually regressing.

[Salo]

The Associated Press

The vehicle developed an error 47 seconds after liftoff and lost command, leading to a higher angle in the flight, said K. Radhakrishnan, chairman of the Indian Space Research Organization.

"That caused a higher stress, breaking up the vehicle," Radhakrishnan told reporters.

[input~2]

http://www.hindustantimes.com/Rocket-failed-after-45-seconds-says-ISRO/Article1-642792.aspx

The  rocket carrying an Indian communication satellite launched from (Sriharikota] on   Saturday began failing after some 45 seconds, the Indian Space Research   Organisation (ISRO) said. “The controllability was lost after 45  seconds after the lift-off. The  control commands to the four strap on  motors of the first stage did not reach,” ISRO chairman K Radhakrishnan  told reporters. He said the first stage performed well till 50 seconds,  and after  that the rocket started failing.

According to him, the  destruct command was issued 63 seconds after the  lift off by the Range  Safety Officer

So there was a first internal break-up at around T₀+50s followed by an explosion triggered by a self destruct command at T0+63s

[jcm]

So we have the guidance failure at 47 seconds and around 10 km altitude? And breakup a few seconds later at 51 s (estimated from video) at a similar altitude? Destruct signal at 63s but by then the rocket had already broken up.
The screenshot at 61s shows altitude 12 km and velocity 0.453 km/s
 but whether that is true realtime data or the planned trajectory is unclear.It looks like it might be real data as the altitude reaches a max of 14.9 km at 77.8 s and 6 km range and then starts to fall.

[jcm]

The original GSLV Mk I's third stage was designated 12KRB by Khrunichev.
Does the new 15-tonne version have a different designation? 15KRB maybe :-)?

[ugordan]

So we have the guidance failure at 47 seconds and around 10 km altitude?

Guidance and control are linked systems, but this is not what I'd call a guidance failure. First Ariane V and one Titan IV launch were guidance system failures - erroneous data fed to the control system. The official report here is the guidance performed as expected, but the proper gimbal commands never reached the engines for whatever reason.

[lnb15k]

RAN 2.7kms means what? It is 2.7kms from the launch pad? It was the first stage fell there?

Probably short for range i.e. downrange distance from the pad.

Thanks, that means it finally went to ground around at 2.7kms from the launch pad. But that for which stage :huh: Who knows satellite may be in the sea bottom in full.

After the breakup three dots were blinking. Except one others stopped blinking after sometime and went missing in atmosphere.

[isro-watch]

http://www.hindustantimes.com/Rocket-failed-after-45-seconds-says-ISRO/Article1-642792.aspx

The  rocket carrying an Indian communication satellite launched from (Sriharikota] on   Saturday began failing after some 45 seconds, the Indian Space Research   Organisation (ISRO) said. “The controllability was lost after 45  seconds after the lift-off. The  control commands to the four strap on  motors of the first stage did not reach,” ISRO chairman K Radhakrishnan  told reporters. He said the first stage performed well till 50 seconds,  and after  that the rocket started failing.

According to him, the  destruct command was issued 63 seconds after the  lift off by the Range  Safety Officer

So there was a first internal break-up at around T₀+50s followed by an explosion triggered by a self destruct command at T0+63s

Yes, watching the flight video also gives credence to this....There was a breakup(at the cryo stage) and then authorized destruction

[isro-watch]

RAN 2.7kms means what? It is 2.7kms from the launch pad? It was the first stage fell there?

Probably short for range i.e. downrange distance from the pad.

Thanks, that means it finally went to ground around at 2.7kms from the launch pad. But that for which stage :huh: Who knows satellite may be in the sea bottom in full.

After the breakup three dots were blinking. Except one others stopped blinking after sometime and went missing in atmosphere.

This is exactly the reason I believe that they can recover the satellite...probably I am going too far... 

[Art LeBrun]

Satellites are relatively fragile structures. Once exposed to a high flow airstream it will  break up. Not to mention the impact..........

[jcm]

So we have the guidance failure at 47 seconds and around 10 km altitude?

Guidance and control are linked systems, but this is not what I'd call a guidance failure. First Ariane V and one Titan IV launch were guidance system failures - erroneous data fed to the control system. The official report here is the guidance performed as expected, but the proper gimbal commands never reached the engines for whatever reason.

OK - so the sound bite version to use is "control failure"?
Or, possibly, interface failure, if the guidance sent the info but the control systems never got it...

Are other folks experiencing extremely slow response from the site today, or is it just me? Got better for a while but now has seized up again.

[William Graham]

RAN 2.7kms means what? It is 2.7kms from the launch pad? It was the first stage fell there?

Probably short for range i.e. downrange distance from the pad.

Thanks, that means it finally went to ground around at 2.7kms from the launch pad. But that for which stage :huh: Who knows satellite may be in the sea bottom in full.

After the breakup three dots were blinking. Except one others stopped blinking after sometime and went missing in atmosphere.

This is exactly the reason I believe that they can recover the satellite...probably I am going too far... 

In the extremely unlikely event that it survived the disintegration, it would have fallen 15 kilometres, which, neglecting air resistance, would give it an impact velocity of about 542 metres per second.

There won't be much to recover.

[John Santos]

RAN 2.7kms means what? It is 2.7kms from the launch pad? It was the first stage fell there?

Probably short for range i.e. downrange distance from the pad.

Thanks, that means it finally went to ground around at 2.7kms from the launch pad. But that for which stage :huh: Who knows satellite may be in the sea bottom in full.

After the breakup three dots were blinking. Except one others stopped blinking after sometime and went missing in atmosphere.

No, it means it was 2.7km downrange from the pad at that time.  It is *not* the expected impact point, which depends on the velocity at the time thrust was cut off and the aerodynamics.

[Art LeBrun]

It appears one of the strap ons broke apart spilling propellants during the initial loss of attitude control............

[input~2]

There was no design fault in the rocket. We  suspect the four connectors to the strap-on motors got snapped,'  Radhakrishnan said.

http://www.sify.com/news/indian-rocket-explodes-seconds-after-launch-intro-night-lead-news-national-kmzvagabccd.html

[ugordan]

There was no design fault in the rocket. We  suspect the four connectors to the strap-on motors got snapped,'  Radhakrishnan said.

http://www.sify.com/news/indian-rocket-explodes-seconds-after-launch-intro-night-lead-news-national-kmzvagabccd.html

That's a contradictory statement if I ever saw one. Is he saying the connectors are designed to snap off less than a minute into first stage flight?