MKremer - 15/3/2008 10:18 PMQuoteNick L. - 15/3/2008 11:35 PMI wonder if this is another case of the "foreign particle". If I recall correctly the last Breeze-M failure (Arabsat 4A) was also during the second burn.
An 'official'/corporate "foreign particle" excuse for an overall launch failure doesn't always tend to define/detail the REAL thing (engineering/production/inspections/otherwise) that actually caused the problem or failure.
These are, after all, private corporations that sign, build, and launch commercial products. {...}
zaitcev - 18/3/2008 1:51 PMQuoteMKremer - 15/3/2008 10:18 PMQuoteNick L. - 15/3/2008 11:35 PMI wonder if this is another case of the "foreign particle". If I recall correctly the last Breeze-M failure (Arabsat 4A) was also during the second burn.
An 'official'/corporate "foreign particle" excuse for an overall launch failure doesn't always tend to define/detail the REAL thing (engineering/production/inspections/otherwise) that actually caused the problem or failure.
These are, after all, private corporations that sign, build, and launch commercial products. {...}
The above explanation fails the Occam razor test: never ascribe to cunning plotting what can be explained by incompetence. I suspect the FROB just failed to find the real cause the last time around, blamed the mythical "particle", the State Commission rubber-stamped it. It's not necesserily incompetence even. Perhaps they were out of telemetry range when the failure occured. Telemetry can be defective even if it's received. The key question now is if they added better data collection for this time, or just crossed their fingers, washed the tanks real clean and hoped for the best. There's even a word in Russian for this kind of behaviour, it would not surprise me if they hoped for "avos'".
One thing interesting about this mission is that it used only three Briz M burns, with one burn (the failed burn) scheduled to last a full 34 minutes, 26 seconds. Most (but I don't think all) of the other Briz M missions used more burns, each of shorter duration, with hours long coast periods between.- Ed Kyle
The failed mission for Arabsat-4A on Feb 28, 2006, was to use 4 Breeze-M firings. The "anomaly in the oxidizer supply subsystem" occurred 27mn30s after the second firing, 3mn 30s short from the nominal 31mn
Definitely something in common with the 32mn13s/34mn26s of Breeze-M for AMC-14
The successful mission in November 2007 with Sirius-4 had 4 Breeze-M firings, longest was 16mn30s
In July 2007, the DirecTV-10 successful mission had 5 Breeze-M burns presumably shorter than 16mn each
Effectively the duration of the burn seems to correlate to failure! Better keep it short!
In July 2007, the DirecTV-10 successful mission had 5 Breeze-M burns presumably shorter than 16mn each
PDJennings - 20/3/2008 9:01 AM
Many of the Proton Breeze M launches of A2100s used a fairly long (30 min) burn. AMC-15 in particular, if I recall correctly, used a three-burn profile similar to AMC-14's. Arabsat 4B had a long burn as well. There were several successful missions with very long burns of the Breeze M.
Not that the failure can't be related to the long burn; two similar occurrences out of 6 or 7 chances are very suspicious.
all other burns were shorter than 19.1mn (and successful!)
The two failures are in the top five! I leave it to the FROB to work on it!
It 's revealing to look back on what was written in the Russian press in April 2006 after the Arabsat-4A failure; Kommersant had this predictive article: http://www.kommersant.ru/doc.aspx?DocsID=669148
A new article published last Tuesday (3/18/2008) also by Kommersant about AMC-14 hints at some consequential delays on forthcoming Russian launches
input~2 - 17/3/2008 9:15 AM
From observation data:
AMC-14 and Breeze-M are both in an HEO orbit inclined at 49.2°
Approximate apsides: apogee= 26450 km; perigee = 770 km
Stephan - 21/3/2008 12:53 PM
AMC-14 apogee has been raised, now 767 x 32 334 Km (still at 49°).
input~2 - 21/3/2008 5:24 AMIt 's revealing to look back on what was written in the Russian press in April 2006 after the Arabsat-4A failure; Kommersant had this predictive article: http://www.kommersant.ru/doc.aspx?DocsID=669148
A new article published last Tuesday (3/18/2008) also by Kommersant about AMC-14 hints at some consequential delays on forthcoming Russian launches
http://www.kommersant.ru/doc.aspx?DocsID=868115
http://www.kommersant.com/p868115/Satellite_Breeze_AMC-14/
Jirka Dlouhy - 21/3/2008 7:18 AM
On the "Novosti kosmonavtiki" pages is an article about failures of DM upper stages, which are produced by RKK Energia because of them Khrunichev decided to develop of Briz upper stages. In russian:
http://www.novosti-kosmonavtiki.ru/content/news.shtml
You may be right; the Planner's guide gives a total propellant mass of 14600 kg in the APT and 5200 kg in the CPT. In the 5-burn case, when they say they deplete the APT right at the end of the 3rd burn, the maximum observed time for depletion I have is 2266s. So 2521s, as in the AMC-14 case, seems too long for feeding the turbopump from the APT only, during the second burn.
If we assume that more than 2388s means a switch to the CPT, they did it successfully at least twice: for Thor-5 (2438s) and for Sirius-4 (2433s).
A standard 9 hour/5 burn mission profile when they switch to the CPT feed when the engine is off, seems safer. That profile has always been successful up to now!
The case of Arabsat-4A was different, it was a so-called "express mission" 4 hour/4 burn with drop of the depleted APT after a cumulative 2055s. (assuming an identical profile to Arabsat-4B)