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

[Kabloona]

Here's the crater from the Proton-M crash in 2007:

Any idea of the scale? I can see no known-sized objects.

IIRC that was the result of a first-second stage separation failure?  It would have impacted at a relatively high velocity but with less unburned propellant, vs. this failure which would have a lower impact velocity but a larger amount of unburned propellant.

JimO: No idea of scale on that crater, and unfortunately it seems the photo is a frame from a video, so not much resolution.

joek: As for comparisons, clearly that previous Proton augered in at high speed, whereas this one looked like more of a slow belly flop. So I'm guessing the crater will look less "lunar" and more broad/shallow and burnt over a wide area, given the quantity of props involved.

[Prober]

easy JimO this is the space age or google maps age?
 
should be easy to get high res pictures by some private sat company.

Well, I want them NOW. And they already exist, from aircraft. I'll be watching the on-line Kazakh press, tomorrow's editions are now being posted. You want to wait for a future fortuitous commercial overflight, do it your way.

Let me go check ISS daylight passes. But a 200 meter crater might not be an easy target for handheld cameras.

hope you can obtain them jimO   I just don't think they want more on this event published.

[Kabloona]

In other words, I figured these things pretty much cleaned themselves up, if you managed to avoid getting poisoned in the immediate aftermath.  Is life more complicated than that?

Yes it's more complicated.  See smoliarm's comments upthread on the persistent toxicity of UDMH.  Also, local Kazakhs have complained for years that their cattle are dying after eating grass contaminated by propellants from spent stages containing residuals.

[Kabloona]

Another preliminary report from Anatoly Zak:

http://www.popularmechanics.com/science/space/rockets/inside-russias-spectacular-rocket-disintegration-15653112?click=pm_news

His sources are saying it was a hard-over TVC on one engine.

Edit: Plus a video apparently taken by spectators (hat tip to arstechnica). Looks like the Proton was heading towards these guys, and fortunately crashed before reaching them. The shock wave hits them about 11 seconds after impact, so they were roughly 3700 meters from point of impact.




And higher resolution, from a better angle.

[hop]

Is life more complicated than that?

Yes. See this post: http://forum.nasaspaceflight.com/index.php?topic=32282.msg1070179#msg1070179

Plus the potential for much greater harm if the next one falls near a populated area. You certainly wouldn't want an Angara 5 falling in your back yard, but Proton has the potential to cause casualties on a much larger scale.

I agree that this failure is not specifically a reason to retire Proton, but getting away from vast quantities of hypergols would undeniably be a Good Thing for everyone.

[sdsds]

If a rocket launches straight up from a pad, then flops over horizontal, it's pretty much guaranteed to be heading away from the pad in one direction or another. No luck involved.

Yes, you're right of course. But compare they way these vehicles behaved with the behavior of Trident II, as seen in the image provided by edkyle. The question is whether they make some "last ditch effort" to maintain horizontal flight (gaining distance from the pad), rather than spiraling.

[simonbp]

The only reason Proton is still in service is because Angara keeps getting delayed.

Or, maybe, just maybe, it has 45% of the commercial GTO market because it's he only option with the capabilities, availability and price with acceptable reliability.

I'm sorry, but if Proton has "acceptable reliability", then I don't know why anyone else bothers...

Angara is not really the answer. Proton only has commercial customers because of its bargain-basement launch costs. Once Falcon Heavy is flying, it will likely eat Proton's lunch. Angara will be almost-exclusively a Russian government launch vehicle.

[Danderman]

Some food for thought: one Russian source is saying that the rocket may have been released half a second too early. What would happen if the rocket T/W is already >1 but with some of the engines still building up to full thrust (with some others already at full thrust)? Could it have caused an engine fire and eventual failure?

IF a Proton were to launch prior to the appointed time, things would go badly for the launch complex. The umbilical leading to the first stage engine compartment are underneath the vehicle, and are protected by clamshells that snap shut a microsecond prior to ignition. If ignition were to come early, and the clamshells were not closed, bye bye connectors.

[Danderman]

If a rocket launches straight up from a pad, then flops over horizontal, it's pretty much guaranteed to be heading away from the pad in one direction or another. No luck involved.

Yes, you're right of course. But compare they way these vehicles behaved with the behavior of Trident II, as seen in the image provided by edkyle. The question is whether they make some "last ditch effort" to maintain horizontal flight (gaining distance from the pad), rather than spiraling.

The standard Russian FTS imposes immediate shutdown of all main engines.

[Danderman]

With all this talk about failed TVC, I am surprised that no one has discussed the unusual gimbal arrangement for the Proton first stage. Each engine has a single degree of freedom gimbal, meaning that each engine can only provide control along one angle. 

If one engine were to gimbal as far as possible and stay that way, I don't know how the remaining five engines could compensate; this leads me to believe that the motion control system normally imposes significant constraints on each engine's movements.

[Danderman]

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.

My source on the immediate shutdown of main engines for launch aborts is standard Russian practice.

As for Proton controllers, I should have written "Proton flight controllers".

[Kabloona]

With all this talk about failed TVC, I am surprised that no one has discussed the unusual gimbal arrangement for the Proton first stage. Each engine has a single degree of freedom gimbal, meaning that each engine can only provide control along one angle. 

If one engine were to gimbal as far as possible and stay that way, I don't know how the remaining five engines could compensate; this leads me to believe that the motion control system normally imposes significant constraints on each engine's movements.

This was discussed to some degree upthread. From what I've read, and someone please correct me if I'm wrong, the engines gimbal in the radial direction, ie into/away from the vehicle centerline. Since each engine has an engine directly opposite on that radial line, any single engine TVC excursion could (theoretically) be cancelled by an opposing excursion from the opposite engine.

What seems to happen, though, is that the guidance system is overwhelmed and can't cope with the combined pitch and roll rates. Once the roll gets out of hand, it's all over.

[Danderman]

I have found conflicting information as to whether Biser-6 was adopted for Proton-M. Some accounts indicate that Biser-3 was still in place as of earlier this year.

[Mapperuo]

I wonder, with all these major networks having played out this crash video. IF the Proton does continue flying, whether Russia may go all China on us and stop broadcasting these launches. 

[Galactic Penguin SST]

New video posted in the updates thread:



Am I seeing things, or did I see one of the six engines reacting "sluggishly" compared with the engine gimbals of the other engines, and that its flame is much weaker than that of the others?

[ugordan]

Am I seeing things, or did I see one of the six engines reacting "sluggishly" compared with the engine gimbals of the other engines, and that its flame is much weaker than that of the others?

I'm seeing two engines that don't appear to gimbal along with the others, perhaps those two were the ones that couldn't contribute to TVC commands for a particular direction GNC wanted them to, given the single degree of freedom.

[Liss]

The standard Russian FTS imposes immediate shutdown of all main engines.

The standard response to loss of attitude (15° of deviation) is the command to shut down engines, yes. But this command is blocked until a certain moment in flight to prevent a repeat of N-1 #5L disaster. For Proton, this is T+42 sec. Of course, in the July 2 launch this moment never occured but the engines effectively shut down when first stage caught fire.

The engine failure version becomes more and more substantiated. Seems that one of the engines was in a bad state from the moment of ignition with very high temperatures in vicinity. Flight safety system which first priority is to protect the launch facility reacted by a faster launch (some 0.4 sec earlier than scheduled). In flight, some components of TVC seem to fail too (probably from that engine's fire) resulting in the space waltz we've seen.

[ugordan]

Perhaps I missed it, but one thing I haven't seen mentioned here is the curious backblast from the engines seen right after liftoff in this video at 0:26: http://www.youtube.com/watch?v=9jQ_tPm0J2E

I don't think I've seen something similar in other Proton launches. There always a bit of brown smoke coming up there, but nothing as "flamey" as this. Could it be another sign that one engine was hard-over immediately and its plume partly impinged on the ground and reflected up instead of being confined to the flame duct?

[Ben the Space Brit]

One thing is certain from those videos: there were flight stability and/or control issues as little as one second after lift-off and the vehicle never recovered.

The size of that explosion, the lack of images of the crash site and its reported proximity to Site 200 raises questions, in my mind at least, of the credibility of ILS's insistence that their launch site is undamaged.

[renclod]

From what I've read, and someone please correct me if I'm wrong, the engines gimbal in the radial direction, ie into/away from the vehicle centerline.

IMO Proton's first stage engines are vectored tangentially .

" The thrust vector is controlled by gimbaling an engine with a hydraulic actuator within 7.5 degrees. To make this possible, the engine is mounted in the yoke bearings by means of special trunnions installed near the chamber throat. "