Independent Arianespace investigation cites design error as cause of Russian launch failure
A just released independent investigation by Arianespace of the Soyuz rocket launch failure that put two European Galileo GPS satellites in the wrong orbits has concluded that the design of the Fregat upper stage, not an assembly error, was at fault for the failure.
The upper stage was not oriented correctly because fuel lines to thrusters had become frozen.
The freezing resulted from the proximity of hydrazine and cold helium feed lines, these lines being connected by the same support structure, which acted as a thermal bridge. Ambiguities in the design documents allowed the installation of this type of thermal “bridge” between the two lines. In fact, such bridges have also been seen on other Fregat stages now under production at NPO Lavochkin. The design ambiguity is the result of not taking into account the relevant thermal transfers during the thermal analyses of the stage system design.
That the Russian investigation found that this arrangement of feed lines happened once in every four stages that were assembled still suggests sloppiness, if not in assembly then in design. The Arianespace investigation, though thorough, thus appears to me to be trying to provide cover for thier Russian partners here.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
A just released independent investigation by Arianespace of the Soyuz rocket launch failure that put two European Galileo GPS satellites in the wrong orbits has concluded that the design of the Fregat upper stage, not an assembly error, was at fault for the failure.
The upper stage was not oriented correctly because fuel lines to thrusters had become frozen.
The freezing resulted from the proximity of hydrazine and cold helium feed lines, these lines being connected by the same support structure, which acted as a thermal bridge. Ambiguities in the design documents allowed the installation of this type of thermal “bridge” between the two lines. In fact, such bridges have also been seen on other Fregat stages now under production at NPO Lavochkin. The design ambiguity is the result of not taking into account the relevant thermal transfers during the thermal analyses of the stage system design.
That the Russian investigation found that this arrangement of feed lines happened once in every four stages that were assembled still suggests sloppiness, if not in assembly then in design. The Arianespace investigation, though thorough, thus appears to me to be trying to provide cover for thier Russian partners here.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Readers: the rules for commenting!
No registration is required. I welcome all opinions, even those that strongly criticize my commentary.
However, name-calling and obscenities will not be tolerated. First time offenders who are new to the site will be warned. Second time offenders or first time offenders who have been here awhile will be suspended for a week. After that, I will ban you. Period.
Note also that first time commenters as well as any comment with more than one link will be placed in moderation for my approval. Be patient, I will get to it.