Quote from: Danderman on 10/14/2013 02:45 pmQuote from: Stan Black on 10/14/2013 06:54 amThe premature start was caused by failure of “Сборка 03”, previously a component changed after twelve launches. Instead it was decided to use it for 32 launches, but failed at 29.By "premature start" does this refer to the 400 millisecond difference in actual launch time from the nominal launch time? What was the impact of this failure?Apparently yes. That component (8U259.SB03) is apparently an electric connector on the base of the launch pad that connects to the rocket, and it was released prematurely. At that time all 6 1st stage engines were (as reported earlier) not yet up to full thrust and their chamber pressure were at 90 kgf/cm² instead of the usual 150-155 kgf/cm². Had the situation continued the rocket would have issued a "engine damaged" command that would have swiveled engine no.4 on the pitch axis to counter-act, but the engines started nominally and the command was not issued. Therefore this has no implications to the accident.Source: Novosti Kosmonavtiki No. 9-2013 via http://www.kosmonavtika.com/lancements/2013/02072013/02072013.html
Quote from: Stan Black on 10/14/2013 06:54 amThe premature start was caused by failure of “Сборка 03”, previously a component changed after twelve launches. Instead it was decided to use it for 32 launches, but failed at 29.By "premature start" does this refer to the 400 millisecond difference in actual launch time from the nominal launch time? What was the impact of this failure?
The premature start was caused by failure of “Сборка 03”, previously a component changed after twelve launches. Instead it was decided to use it for 32 launches, but failed at 29.
The Mars lander that crashed on landing had a code bug causing the engine control computer to not ignore the known in advance false positive signal that the touch down sensors were going to generate when the spring loaded legs snapped open at 100s m height above actual touch down.
I publish here an exclusive high-resolution slow-motion video of the launch :http://www.kosmonavtika.com/lancements/2013/02072013/02072013photos.html(last video in the list)
This Proton launch where they had literally hammered in the inertial measurement units upside down will always be one of the most epic launch failures!
Not true - I ran the US Failure investigation.
The Yaw rate sensors were a blind install with off center pin holes that were supposed to make sure that the unit was installed in correct orientation. Unfortunately the pins on the mounting bracket were only press fit...
...so when the new tech installed them blind by reaching through an access hole, he slid them onto the studs, and then torqued the nuts down on the studs. The act of torquing the studs drove the press fit pins back in the bracket...
...and allowed the unit to sit flush on the bracket. The debris of the units showed the mark on the baseplate that the alignment stud made as it was driven back into the bracket. Root cause....
They were building so many Protons, they used a secondary horizontal stand at the factory for building the stage. The primary stand only allowed 1 orientation of +Y up so the install documentation did not ask for orientation verification. The secondary stand allowed...
either +Y or -Y up, and this LV was in -Y up. The tech installed the unit per the documentation, but the stage was inverted. The quality person looked through an access hatch after install and verified the orientation arrow on the unit was pointing up per the documentation.
The tech was new so did not realize the force that was needed for the nuts was atypical, and the quality documentation did not ask for verification that alignment studs were in the holes.
