Proton-M Failure Reaction and Discussion Thread - July 2, 2013

[Danderman]

"In the first few seconds the engines are not terminated to save the launch site. "

How soon is that impairment of the FTS removed?

[R7]

"In the first few seconds the engines are not terminated to save the launch site. "

How soon is that impairment of the FTS removed?

http://forum.nasaspaceflight.com/index.php?topic=31191.msg1069845#msg1069845

45 seconds?

[wolfpack]

<amateur detective mode>
From the available videos, it seems that the rocket had 3 pitch overs - each one larger than the previous one, and it seems that the rocket was in an excessive roll right after liftoff that continues to accelerate till breaking up.

I have a hypothesis that was first mentioned by a Russian forum member here:

1. For some reason the Proton started to roll excessively within a few seconds of liftoff - reasons not yet known as this point.

2. The excessive roll caused the rocket to start to pitch over towards a certain direction due to torque from the angular acceleration (remember tau = I * alpha?) - it may have been magnified by the initial pitch over command.

3. Sensing that the rocket is pitching over limits, it attempts to gimbal some of the engines towards the other direction, but since the roll is accelerating (and may already be out of control by then), it over-corrects in the opposite direction and caused the rocket to lose pitch (and almost certainly yaw) control.

4. By then the worsening roll puts the rocket in a positive feed-back mechanism - the more the rocket tries to correct the pitch, the more it over-pitches in the other direction. This third pitch over finally sends the rocket horizontally and points it towards the ground. The rocket continues to roll crazily until it breaks up - heads first (tau = r * F) and then the whole rocket as the fuel tanks blasted open. Then it impacted on the ground.

So what caused the excessive roll? Engine loss or partial thrust? Problem with engine gimbals? (failure in one of the six engines is apparently enough to send the rocket towards the ground) Erroneous data from the inertial platform sending the rocket to roll violently? Control system software bug in a specific environment that went out of control? All these would probably be known when all the telemetry data is analyzed in a few day's time.

Any comments on my thoughts?

</amateur detective mode>

Any control system has what's known as ROC (region of convergence). Get outside that and it will never recover. I don't know what it is for a Proton-M rocket, but its designers do. That's what should be programmed into an FTS - max rates and angles. Exceed them and game over.

Airplanes do the same thing, except the B777 won't blow itself up, it will just bank at a max rate to a max angle if you hold the control yoke hard over, and then start beeping at you to please stop.

[Danderman]

"In the first few seconds the engines are not terminated to save the launch site. "

How soon is that impairment of the FTS removed?

http://forum.nasaspaceflight.com/index.php?topic=31191.msg1069845#msg1069845

45 seconds?

I would treat that as a rumor and not a fact until confirmed. 45 seconds does not give Proton controllers the ability to avoid impact in the city of Baikonur.

[wolfpack]

You prefer the alternative?

I would think they give more attention to quality assurance on manned launches than to their unmanned launches and the launch track record seems to support that.

Certainly not. My point is a LAS can kill the crew just as easily as an errant booster. LAS is not fail-safe, never intended to be.

I'm certain they do put far, far more care into manned launches than unmanned. Still doesn't change the fact that we are one anomaly away from potentially de-crewing the ISS.

But that has no bearing on Proton, so I'll not discuss it further here, in the interest of staying OT.

Name one such an abort event/system that wouldn't. LAS should have no bearing on initiating an anomaly investigation.

Never said it would.

[Kabloona]

Here's an informative source of Proton info. Google translate is not perfect but it it seems to say ( in the Stage 1 section) that the brown plume that ugordan commented on is a normal result of an MR change in which UDMH is throttled in order to reduce thrust in one engine, which results in unburned NTO, hence the brown plume. This throttling of one engine is apparently intended to operate as a crude form of TVC, perhaps for the initial pitch program.

http://www.bernd-leitenberger.de/proton.shtml

[JimO]

Major new information here, I'm on another deadline, sorry, no time to summarize:
http://english.pravda.ru/science/tech/02-07-2013/125008-proton_m_explosion-0/

[Danderman]

Major new information here, I'm on another deadline, sorry, no time to summarize:
http://english.pravda.ru/science/tech/02-07-2013/125008-proton_m_explosion-0/

Some contradictory information, but this source states that the engines "went off" at T  +17 seconds. I could not see thrust termination in the video, though.

[Kabloona]

Major new information here, I'm on another deadline, sorry, no time to summarize:
http://english.pravda.ru/science/tech/02-07-2013/125008-proton_m_explosion-0/

The political commentary by Gubarev is intriguing background. It seems the Russian Academy of Sciences is undergoing a "hostile takeover" by the oligarchy, with a resulting brain drain which doesn't bode well for the future of Russian space programs.

http://rt.com/politics/outraged-suggested-reform-academy-483/

[ugordan]

I would treat that as a rumor and not a fact until confirmed. 45 seconds does not give Proton controllers the ability to avoid impact in the city of Baikonur.

Perhaps, but on the other hand what is your source on the immediate shutdown of the engines, as you claimed earlier? The "flyaway" I mentioned is whatever the vehicle does to prevent destruction of the launch pad, if possible. Whether there is any actual pitching or just keeping engines alive, I don't know.

Also, what do you mean by Proton controllers, it makes it sound as if someone takes over the control of the rocket.

[ugordan]

4. By then the worsening roll puts the rocket in a positive feed-back mechanism - the more the rocket tries to correct the pitch, the more it over-pitches in the other direction.

Interesting speculation. What if the TVC overcorrections were due to the additional factor of air drag trying to tumble the vehicle and the GNC just fighting it hard (I assume a normal flight envelope wouldn't expect to see that level of torques and the control gains could be set correspondingly to that expectation). The faster it went, the more divergent this process

[Jim]

"In the first few seconds the engines are not terminated to save the launch site. "

How soon is that impairment of the FTS removed?

http://forum.nasaspaceflight.com/index.php?topic=31191.msg1069845#msg1069845

45 seconds?

I would treat that as a rumor and not a fact until confirmed. 45 seconds does not give Proton controllers the ability to avoid impact in the city of Baikonur.

It was almost 30 seconds of flight for this launch with all engines running

[Kabloona]

I would treat that as a rumor and not a fact until confirmed. 45 seconds does not give Proton controllers the ability to avoid impact in the city of Baikonur.

Perhaps, but on the other hand what is your source on the immediate shutdown of the engines, as you claimed earlier? The "flyaway" I mentioned is whatever the vehicle does to prevent destruction of the launch pad, if possible. Whether there is any actual pitching or just keeping engines alive, I don't know.

Also, what do you mean by Proton controllers, it makes it sound as if someone takes over the control of the rocket.

This excerpt from the Pravda article does imply active control. Don't know if the statement itself is accurate, though.

"Main engines were working before the rocket hit the ground, enabling flight control officers to take the space vehicle from the launch pad and avoid damage on the ground."

Edit: Also, given the high roll rate during the last half of the flight, hard to imagine the "controllers" really had much control over the flight path...seems more like wishful thinking and luck.

[Jim]

Controller - planners.  Just inaccurate reporting.  Launch vehicles are autonomous, especially Russian ones (no range safety receiver to receiver commands from)

[Rusty Adding Machine]

"In the first few seconds the engines are not terminated to save the launch site. "

How soon is that impairment of the FTS removed?

http://forum.nasaspaceflight.com/index.php?topic=31191.msg1069845#msg1069845

45 seconds?

In his tweets, Anatoly Zak has said 45 seconds, but in this article, he says 42 seconds:

http://www.russianspaceweb.com/proton_glonass49.html

Not that it would seem to have mattered much in this case which it is.

[PahTo]

Wow--that was something!  Thanks for the linked video back on page 4.  Sure seems like a software or command signal issue as opposed to a TVC hardware issue (as many have noted, TVC was clearly functioning, and engines were running).

No doubt the fuels the vehicle uses are toxic, and that's an issue, but I don't think it spells the end of Proton.  I wonder if the Chinese will hurry along their RP-1/LH2 rockets in light of this (not to mention their own Long March "issues").

Puts in to question when MLM will launch.  Perhaps more importantly, and as many have speculated over the years, is Russia's space industry running beyond (human) capacity?  This is no insult to the dedicated people involved, I have respect for any and all spaceflight professionals.  Still, people can only do so much...

[Mapperuo]

CNN article is classic.

Not only is the photo of a Soyuz rocket there's this gem...

Authorities have suspended further launches of the rockets as they investigate what caused the explosion.

I believe the cause was crashing into the ground but I'm no expert in explosions.

[ugordan]

Speaking of that, I like the wording in the ILS release:

About ten seconds after lift-off from the Baikonur Cosmodrome in Kazakhstan at 8:38 am local time, the rocket veered off of its flight path and returned to earth.

Almost sounds graceful.

[Kabloona]

Controller - planners.  Just inaccurate reporting.  Launch vehicles are autonomous, especially Russian ones (no range safety receiver to receiver commands from)

The Zak article posted above is saying that Krunichev claims they issued an emergency engine shutdown command at T+17, which if true implies (a) they do have some onboard receiver for emergency engine shutdown commanding and (b) that system failed.

[Stan Black]

Was this intended to fly on a 35° azimuth to a 64·8° inclination orbit?