RIA Novosti: Space Radiation Blamed for Phobos-Grunt Crash14:52 31/01/2012 // http://en.ria.ru/science/20120131/171047665.htmlTASS: Phobos-Grunt chips supposedly were counterfeithttp://www.itar-tass.com/en/c32/330734.htmlNatalya Vedeneyeva report in Moskovskiy Kosmolets: 'They lie to us about Phobos-Grunt' says that experts have established that Russian specialists are to blame for failure of the space craft Phobos-Grunt http://www.mk.ru/science/interview/2012/01/30/665712-nam-vrut-pro-fobosgrunt.html
Okay, so which story are we now to believe?
Quote from: robertross on 01/31/2012 07:12 pmOkay, so which story are we now to believe?Look on the bright side - at least someone there is talking some sense (Moskovskiy Kosmolets).
1) It launched: that part worked.2) Everything else: needs some work, if not a complete overhaul.
1. SummaryAnalysis of the USSTRATCOM TLEs for the period 2011 Nov 10-20 UTC reveals evidence of at least 10 orbit changes. They were the result of coplanar, posigrade manoeuvres that cumulatively rotated the line of apsides +14.1 deg and increased the perigee and apogee 10.9 km and 1.4 km, respectively. Their total delta-V was approximately 18.3 m/s.The manoeuvres almost certainly are attributable to the four 11D457F bipropellant 53.9 N thrusters that faced -X (aft) in the vehicle's coordinate system. Their main purpose was attitude control, but also propellant settling (ullage burns) prior to main engine firings. Consumption of fuel plus oxidizer was about 98 kg. Total burn duration was about 1289 s.In the planned mission, the main engine would have performed two lengthy burns 127 min apart to exit LEO and head for Mars. Both burns would have been preceded by 58 s ullage burns, that would each have consumed 4.4 kg of fuel plus oxidizer and imparted delta-V of 0.82 m/s.Ullage burns best fit the magnitude of the manoeuvres, their precisely in-plane, posigrade thrust vector, and their frequency, so I am 95 percent confident of that explanation. Since the total manoeuvre delta-V is equivalent to approximately 22 single ullage burns - roughly double the 10 orbit changes evident in the TLEs - it is reasonable to speculate whether the ullage burns occurred in pairs at the mission-nominal 127 min spacing. My analysis reveals that this was a possibility, but I cannot prove it.Sections 2 and 3 describe how I identified and quantified the manoeuvres. Section 4 relates them to the propulsion system, and quantifies the fuel consumption and burn duration. Section 5 discusses the ullage burn hypothesis, and speculates about the potential value of a more sophisticated version of this analysis to the Russian failureinvestigation.
Ted's fine analysis is reported straight in Russian here:"Фобос-Грунт" более 20 раз включал двигатели ориентации - эксперт13:59 01/02/2012 // http://www.ria.ru/science/20120201/553866833.html
No discussion of the report? Or has everyone snuck off elsewhere?
Got an English translation that is readable?
4) where would we be without you? keep up the good work.