The recontact was between first and second stage. They were nowhere to orbital. There was the talks about the SeaLaunch and Intelsat 19, I think?
Quote from: kevin-rf on 05/13/2015 02:51 pmQuote from: baldusi on 05/13/2015 02:15 pmThe recontact was between first and second stage. They were nowhere to orbital. There was the talks about the SeaLaunch and Intelsat 19, I think?Intelsat 19 was due to a manufacturing defect in the solar panels. The defect bit three Space Systems Loral Satellites (Estrela do Sul/Telstar 14, Estrela do Sul-2/Telstar 14R, Intelsat IS-19).Failed to deploy. Cable clip.
Quote from: baldusi on 05/13/2015 02:15 pmThe recontact was between first and second stage. They were nowhere to orbital. There was the talks about the SeaLaunch and Intelsat 19, I think?Intelsat 19 was due to a manufacturing defect in the solar panels. The defect bit three Space Systems Loral Satellites (Estrela do Sul/Telstar 14, Estrela do Sul-2/Telstar 14R, Intelsat IS-19).
Quote from: Space Ghost 1962 on 05/13/2015 08:45 pmQuote from: kevin-rf on 05/13/2015 02:51 pmQuote from: baldusi on 05/13/2015 02:15 pmThe recontact was between first and second stage. They were nowhere to orbital. There was the talks about the SeaLaunch and Intelsat 19, I think?Intelsat 19 was due to a manufacturing defect in the solar panels. The defect bit three Space Systems Loral Satellites (Estrela do Sul/Telstar 14, Estrela do Sul-2/Telstar 14R, Intelsat IS-19).Failed to deploy. Cable clip.According to this the fault was not the clip that was just a symptom after the initial failure http://seradata.com/SSI/2013/01/obscure-solar-array-failure-du/
"It found that it was inadvertent solar array pressurisation and exposive decompression that was the underlying cause.""... during the launch phase, the satellites’ solar arrays had actually become pressurized relative to their ambient environment as the launch vehicle rose in altitude ... led to an explosive event which damaged the array’s deployment mechanism ... manufacturing defect that was found to be the root cause ... susceptible to explosive depressurization.""Although the exact cause remained a mystery, evidence that an explosive event had been detected by onboard sound sensors hinted that the launch vehicle was in some way at fault. "
Quote from: mn on 05/15/2015 12:51 amQuote from: Space Ghost 1962 on 05/13/2015 08:45 pmQuote from: kevin-rf on 05/13/2015 02:51 pmQuote from: baldusi on 05/13/2015 02:15 pmThe recontact was between first and second stage. They were nowhere to orbital. There was the talks about the SeaLaunch and Intelsat 19, I think?Intelsat 19 was due to a manufacturing defect in the solar panels. The defect bit three Space Systems Loral Satellites (Estrela do Sul/Telstar 14, Estrela do Sul-2/Telstar 14R, Intelsat IS-19).Failed to deploy. Cable clip.According to this the fault was not the clip that was just a symptom after the initial failure http://seradata.com/SSI/2013/01/obscure-solar-array-failure-du/Quote"It found that it was inadvertent solar array pressurisation and exposive decompression that was the underlying cause.""... during the launch phase, the satellites’ solar arrays had actually become pressurized relative to their ambient environment as the launch vehicle rose in altitude ... led to an explosive event which damaged the array’s deployment mechanism ... manufacturing defect that was found to be the root cause ... susceptible to explosive depressurization.""Although the exact cause remained a mystery, evidence that an explosive event had been detected by onboard sound sensors hinted that the launch vehicle was in some way at fault. "
Article does not clarify source of "pressure event" but by implication the third stage DM-SLB is suggested. Like perhaps tank pressurization prior to shroud separation.
Specifically, during the launch phase, the satellites’ solar arrays had actually become pressurised relative to their ambient environment as the launch vehicle rose in altititude. This eventually led to an explosive event which damaged the array’s deployment mechanism and structure. It was a manufacturing defect that was found to be the root cause including overly pinching the ends of the panels which would not let gasses vent from the honeycomb structure, and having insufficent bonding of the layers of the panel making it more susceptible to explosive depressurisation.
Whoa, that would be.....um, stupid if this turn out to be the cause of the accident! Why would a "blackbox" system be used with the rocket and spacecraft not syncing the separation actions? Or does every other rocket out there do that?
Looks like Roscosmos has just reported the cause of the accident: http://www.federalspace.ru/21513/If I am reading the Internet translations correctly (can someone check the translations?), it looks like the spacecraft was damaged during separation from the third stage due to (pogo?) resonance problems at the connection interface, which was not taken into account during mission analysis for the Soyuz-2.1a rocket.
However, I read something more conflicting since this rocket and the Soyuz share similar/identical third stage motors. I can't find that specific source, but I believe another report indicated a specific turbopump design flaw as well as quality control issues as the cause of that failure. I found one link on a blog that summarizes things differently. Clarification is needed.http://english.tachyonbeam.com/2015/05/31/the-proton-m-mishap-on-may-16-was-caused-by-a-design-flaw/
Quote from: MattMason on 06/01/2015 02:43 pmHowever, I read something more conflicting since this rocket and the Soyuz share similar/identical third stage motors. I can't find that specific source, but I believe another report indicated a specific turbopump design flaw as well as quality control issues as the cause of that failure. I found one link on a blog that summarizes things differently. Clarification is needed.http://english.tachyonbeam.com/2015/05/31/the-proton-m-mishap-on-may-16-was-caused-by-a-design-flaw/Your confusing the Proton failure on May 16th with this Soyuz failure on April 28th. Different launch failures...
Quote from: kevin-rf on 06/01/2015 03:00 pmQuote from: MattMason on 06/01/2015 02:43 pmHowever, I read something more conflicting since this rocket and the Soyuz share similar/identical third stage motors. I can't find that specific source, but I believe another report indicated a specific turbopump design flaw as well as quality control issues as the cause of that failure. I found one link on a blog that summarizes things differently. Clarification is needed.http://english.tachyonbeam.com/2015/05/31/the-proton-m-mishap-on-may-16-was-caused-by-a-design-flaw/Your confusing the Proton failure on May 16th with this Soyuz failure on April 28th. Different launch failures...Right, but same third stage design or engine type?
Right, but same third stage design or engine type?
In the Roscosmos statement issued on Monday, the agency announced that the likely culprit in the Progress M-27M failure lies within a design flaw in the spacecraft separation system and associated frequency-dynamic characteristics.According to the State Commission, these properties were not fully studied as part of the design work that went into the accommodation of Soyuz and Progress spacecraft atop the Soyuz 2-1A rocket.