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#280
by
Rebel44
on 30 May, 2015 16:27
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......
Finally, expect that the next commercial Proton launch will not be the next launch. I'm sure insurers would like to see at least one successful Proton launch before insuring a Proton payload. Rate increases are spread throughout the satellite insurance industry (have to correct for the lost money as quickly as possible). These increases will not be as much as some people seem to think since it won't just be Proton insurance rates that increase. Proton insurance rates were already high, so it would be hard to make those rates much higher without causing some Proton launches to become "self-insured". If a satellite is self-insured, the insurance industry receives no premiums, which does not help it recover from paying out on MexSat-1.
Andy
If I am an insurance company and someone asks me to insure satelite launch worth $400M on a vehicle with 15% failure rate, you can bet your house, that insurance will be over 15% of value of potential payout, because insurance companies are not willing to lose the money on its contracts. For insurance company, not getting a contract, is a much more preferable, than statistical certainty, of losing money on such contract.
Also, since insurance business isnt a monopoly, ability to spread a loss to other customers (launching on Arianespace and SpaceX rockets) is fairly limited.
And, 15% is still better than 5/6th successful and certainly not a "statistical certainty" of failure. If the premiums are high enough, then many companies would cover that bet. Again, self-insurance is always an option.
If you charge less, than you are statistically likely to pay out over a long term, you will lose money - and insurance companies dont want to do that (lol).
Since Proton isnt he only choice (we are talking about new contracts), high failure rate and high insurance will drive customers to other launch companies (Arianespace, SpaceX, Orbital, ULA etc.), where they have better chance of success and viable insurance cost.
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#281
by
edkyle99
on 30 May, 2015 16:48
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I wonder. In recent years Khrunichev has been more and more "enhancing" Proton M to squeeze more GTO performance. Could the shaving of a few kg in the bracket holding the turbopump, or of some associated structure, have allowed more vibration modes?
- Ed Kyle
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#282
by
cscott
on 30 May, 2015 17:34
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I wonder. In recent years Khrunichev has been more and more "enhancing" Proton M to squeeze more GTO performance. Could the shaving of a few kg in the bracket holding the turbopump, or of some associated structure, have allowed more vibration modes?
- Ed Kyle
If the 1988 failure was due to the same root cause, it seems that recent changes are not (solely) to blame.
Hers's Anatoly Zak's report:
http://www.russianspaceweb.com/mexsat1.html#outcome
Aleksandr Medvedev, First Deputy Director at GKNPTs Khrunichev, confirmed during the briefing that the Proton failure on Jan. 18, 1988, had also stemmed from the same design flaw. However, at the time, the rocket completely lacked vibration load sensors and investigators had to work in the dark in search for a culprit, Ivanov added.
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#283
by
A12
on 30 May, 2015 17:50
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I wonder. In recent years Khrunichev has been more and more "enhancing" Proton M to squeeze more GTO performance. Could the shaving of a few kg in the bracket holding the turbopump, or of some associated structure, have allowed more vibration modes?
- Ed Kyle
Is this kind of defect undetectable during ground tests ?
One could think that, after that changes, they should test the stage on the bench.
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#284
by
cscott
on 30 May, 2015 19:42
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They can detect it on ground now that they know what they are looking for. And in fact the Fine Article states that they did just that in order to confirm the diagnosis:
The telemetry from those sensors complemented by ground tests, including a live firing of the engine, enabled to finally re-qualify the issue as an old design flaw rather than poor production. As it turned out, under certain border-line conditions, an improperly balanced shaft of the turbopump tends to excessively vibrate, deform and fail. Investigators determined that the same problem doomed three launches out of more than 400 Proton missions since 1965.
The trick is knowing what to look for, I expect. It's a very rare failure mode.
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#285
by
A12
on 30 May, 2015 20:54
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The trick is knowing what to look for, I expect. It's a very rare failure mode.
I understand that, I was referring to standard acceptance tests, or whatever are called, not to the one they did purposely after the accident. Anyway you answered: it is a rare case that went undetected for decades, space is hard...
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#286
by
sdsds
on 30 May, 2015 23:37
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I'm trying to understand how difficult it is to proactively perform the kind of testing which was here done retroactively, i.e. making the failure occur in a test article.
I'm guessing that with the sensor readings from the failed flight, they could mechanically induce in a test pump vibrations at what turns out to have been a natural resonant frequency.
In things that might shake apart, how standard is it (in US/Japan/European aerospace industries) to test for resonance of this type across a wide range of possible frequencies before deploying the system?
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#287
by
cscott
on 31 May, 2015 01:59
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In my reading of the article, "border-line conditions" must likely means a combination of factors. That is, it's not enough to test against the entire vibration frequency range, it's doing that at the same time you cycle through the entire frequency range of two or three or ten other things, to find the one point where they all interact in exactly the wrong way.
It's the combinatorics that get you with brute-force testing strategies. Better to approach things analytically... but then again sometimes you have to know what to look for. Rare failures tend to require just enough things to go wrong at once to sneak past brute force tests (frequency sweeps, etc) and just strange enough to escape analytic notice. Murphy is devious.
And of course, it will be a *long* time before the statistics will be able to tell you if the fix they implement is actually better than the original problem. (We could find out quickly if it's worse, though.)
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#288
by
Steven Pietrobon
on 31 May, 2015 04:02
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The report is interesting in that, unlike what was reported during the live broadcast, telemetry was flowing at the time of the accident. It seems that only ILS was not getting telemetry during much of ascent. That's an interesting coincidence.
The telemetry they used was probably from before the actual failure and loss of telemetry. With the additional sensors, that would have shown the high vibration levels that caused the failure.
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#289
by
JazzFan
on 02 Jun, 2015 19:15
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#290
by
MattMason
on 02 Jun, 2015 20:30
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#291
by
Stan Black
on 01 Jul, 2015 15:17
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Someone help translate please!
From KBKhA annual report:-
4. Направить в Роскосмос предложения о необходимости финансирования проведения работ по двигателю 8Д611 вследствие произошедших в 2013 и 2014 годах аварийных пусков РН «Протон-М»;
http://www.e-disclosure.ru/portal/FileLoad.ashx?Fileid=1094198The 8Д611 is the steering engine.
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#292
by
baldusi
on 01 Jul, 2015 16:51
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Someone help translate please!
From KBKhA annual report:-
4. Направить в Роскосмос предложения о необходимости финансирования проведения работ по двигателю 8Д611 вследствие произошедших в 2013 и 2014 годах аварийных пусков РН «Протон-М»;
http://www.e-disclosure.ru/portal/FileLoad.ashx?Fileid=1094198
The 8Д611 is the steering engine.
From google translate it would seem a request for funds to Roscosmos to
redesign the RD-0214 turbopump that was found to be unreliable in the failed MexSat-1 launch. That's the Proton-M third stage engine vernier engine, with the RD-0213 make the RD-0212 propulsion module. I have it as the 8D811, both from astronautix and lpre.de, so I guess they made a typo?
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#293
by
Stan Black
on 02 Jul, 2015 16:56
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Someone help translate please!
From KBKhA annual report:-
4. Направить в Роскосмос предложения о необходимости финансирования проведения работ по двигателю 8Д611 вследствие произошедших в 2013 и 2014 годах аварийных пусков РН «Протон-М»;
http://www.e-disclosure.ru/portal/FileLoad.ashx?Fileid=1094198
The 8Д611 is the steering engine.
From google translate it would seem a request for funds to Roscosmos to redesign the RD-0214 turbopump that was found to be unreliable in the failed MexSat-1 launch. That's the Proton-M third stage engine vernier engine, with the RD-0213 make the RD-0212 propulsion module. I have it as the 8D811, both from astronautix and lpre.de, so I guess they made a typo?
It is the reference to 2013 I am not sure about.
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#294
by
McDew
on 03 Jul, 2015 00:47
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Someone help translate please!
From KBKhA annual report:-
4. Направить в Роскосмос предложения о необходимости финансирования проведения работ по двигателю 8Д611 вследствие произошедших в 2013 и 2014 годах аварийных пусков РН «Протон-М»;
http://www.e-disclosure.ru/portal/FileLoad.ashx?Fileid=1094198
The 8Д611 is the steering engine.
From google translate it would seem a request for funds to Roscosmos to redesign the RD-0214 turbopump that was found to be unreliable in the failed MexSat-1 launch. That's the Proton-M third stage engine vernier engine, with the RD-0213 make the RD-0212 propulsion module. I have it as the 8D811, both from astronautix and lpre.de, so I guess they made a typo?
It is the reference to 2013 I am not sure about.
The engine for the launch failure in 2014 was manufactured in 2013.
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#295
by
Nicolas PILLET
on 03 Jul, 2015 16:30
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#296
by
Stan Black
on 05 Jul, 2015 11:05
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The design of the Proton rocket has not remained static, but evolved over many years.
On the Proton rocket there are three types of engine. The RD-253, later RD-275 and now RD-276 on the 1st stage. On the 2nd and 3rd stages are variations of the same type of engine: RD-0210, RD-0211 and RD-0213. To support the 3rd stage is a steering engine the RD-0214; one pump and four combustion chambers.
Anik posted over on N.K. forum reference to changes made to the steering engine bearings in 1985.
http://novosti-kosmonavtiki.ru/forum/messages/forum12/topic13651/message1387073/#message1387073Coincidently, this was at the same time that two enhanced Proton-K were being prepared for the launch of Kvant and Mir. Those two rockets featured the RD-253 engines forced with an additional 6½% thrust, and the upper stage RD-0210/RD-0211 with 1½%. These changes lead to later launches having RD-253 engines being operated with an additional 2% thrust; and followed by the introduction of the RD-275 with 7% more thrust then the RD-253.
Part of the Proton-M introduction saw further revisions to the RD-0210/RD-0211 engines being introduced to the Proton-K; sometimes referred to as phase II, but not to be confused with the phase II Proton-M rockets. The Proton-M was to further force the engines thrust; an additional 2% from the RD-275 and 5% from the RD-0210 and RD-0211. The improvements, but without an increase of thrust, were also introduced to Proton-K. It looks like the ‘quick’ introduction of enhanced RD-0210 and RD-0211 after the crashes of 1999, was in-part from an already existing improvement programme.
http://www.spaceflightnow.com/station/zvezda/000707preview/index4.htmlBut after all theses revisions to the Proton, it looks like the RD-0214 was not changed since 1985? The only possible changes would have been required to support the Proton-M phase III depletion of 3rd stage propellant?
http://www.ilslaunch.com/assets/pdf/Sat-Finance-Dec-2009.pdfIn 2005 KBKhA in their Annual Report referred to problems with the steering engine during the launch of Ekspress-AM2. In the 2014 Annual Report there was reference to problems both in 2013 and 2014? The 2014 is the known one that took down Ekspress-AM4R.
Khrunichev and Roscomos have been paying for improvements to the RD-0214 steering engine; including in 2012 to ‘protect engine flow regulators from foreign particles’, and in 2014 to ‘test engine rotor during high-frequency tests’.
http://www.zakupki.gov.ru/pgz/documentdownload?documentId=70564444http://www.zakupki.gov.ru/223/plan/public/download/download.html?id=1596911http://www.zakupki.gov.ru/223/plan/public/plan/info/actual-documents.html?planId=110810&planInfoId=608587&versioned=&activeTab=1It appears the RD-0214 steering engine’s problems have been around for a long time.
Thanks to Fregate with translations.
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#297
by
baldusi
on 06 Jul, 2015 12:44
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I have it as the 8D811, both from astronautix and lpre.de, so I guess they made a typo?
Hmmm... I have 8D611 on my website...
http://www.kosmonavtika.com/lanceurs/proton/partie2/3.html
I'm really interested in solving this conundrum. Can Nicolas, Anik, Fregat or Russianhalo get an authoritative answer? I've wrote the Wikipedia article on the RD-0214 and I want to get all facts right.
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#298
by
owais.usmani
on 28 Jul, 2015 18:20
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http://www.russianspaceweb.com/mexsat1.html#outcomeThe investigation into the MexSat-1 failure established that a fast spinning shaft inside a turbine of the RD-0212 engine propelling the third stage can break easily due to excessive vibrations. (The turbine is designed to pump propellant into four thrusters which steer the rocket in flight.)
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#299
by
Chris Bergin
on 03 Aug, 2015 16:11
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INTERNATIONAL LAUNCH Services Concludes REVIEW OF the CENTENARIO Proton Launch FAILURE Investigation
August 3, 2015 - The International Launch Services (ILS) Failure Review Oversight Board (FROB) concluded its work, concurring with the most probable cause and the associated corrective action plan which were identified by the Russian Interagency Commission (IAC) as a result of the May 16 Proton launch vehicle failure carrying the Centenario spacecraft.
The members of the FROB reviewed the findings and conclusions from the IAC along with results from testing and investigations that the IAC directed to be performed by Khrunichev and their subsidiaries. Based on the data presented by KhSC, the FROB agreed that the most probable cause of the failure was a result of a higher than expected vibration environment most likely caused by the combination of a marginal mechanical joint used to mount the Stage III steering engine turbo pump and a steering engine turbopump rotor material that had marginal strength under maximum operating environments. This led to a premature shutdown of the turbopump and loss of Stage III control authority and subsequently to the failure of the mission during 3rd stage operation approximately 497 seconds after liftoff.
“The participating customers, insurance underwriters and independent subject matter experts are to be commended for their valuable contributions during the extensive FROB review process. We thank our customers for their support as we prepare for the safe return to flight of ILS Proton,” said ILS Vice President and Chief Technical Officer, John Palmé.