MOSCOW. Dec 12 (Interfax) - The accident that occurred following the November 28 launch from the Vostochny Cosmodrome, in Russia's Amur region, was caused by an error in the Fregat upper stage's algorithm that cannot be identified via existing methods, Roscosmos head Igor Komarov told reporters.
"Specialists have concluded that the emergency was caused by the upper stage's impossible-to-predict conduct after its separation from the launch vehicle," Komarov said.
"Unfortunately, we have encountered a problem which was not related to quality or production discipline. Rather, it was linked with the specifics of the software which was first tested some 20 years ago. It was the first launch of a Soyuz-Fregat combination from this cosmodrome. I have to say that we could have averted the accident if the launch had been conducted during another season and if there had been slightly different impact areas," Komarov said.
The Fregat upper stage was developed in 1998 and has been successfully used 62 times to deliver payloads into orbits during launches from the Baikonur and Plesetsk Cosmodromes and the Kourou Space Center since then, he said.
"The step-by-step analysis of what happened allowed us to reveal new questions that were not explored earlier, and they are actually linked with the history of the development of this upper stage. Research and development efforts were launched in 1998 and were prepared for the Fregate's first launch in 2000. The upper stage's operating procedure was tested then. In other words, after this algorithm was tested, sixty-two Fregat launches were carried out in which this feature did not reveal itself and there were no complaints about its function," he said.
Roscosmos first deputy general director Alexander Ivanov, told reporters that the immediate reasons for the accident were flaws in the upper stage's software that existing methods had failed to expose.
"All members of the emergency commission agreed with the conclusions. The cause was established definitively. The accident was caused by flaws of the algorithms of the Fregat upper stage's control system software that showed itself during the launch from Vostochny Cosmodrome. Operating procedure of the control system resulted in an erroneous determination of the orientation of the upper stage following its separation from the launch vehicle with the reference azimuths of the launch vehicle and the upper stage set at the launch pad of the Vostochny Cosmodrome," he said.
However, "existing mathematical methods of simulating a satellite orbit insertion process were unable to detect such an error," he said.
At the same time, there were no complaints about the technical condition of the launch vehicle, the upper stage and the cosmodrome.
The commission established during its work that all measures taken at the launch pad as part of preparations for the launch could not have caused such a result. There are no complaints about the work of the Vostochny Cosmodrome and its systems, including the actions of the operational crew in charge of that launch and the cosmodrome's hardware, Ivanov said.
The launch vehicle operated in strict compliance with the flight sequence. "The upper stage itself and its components - the propulsion systems and the control system - functioned consistent with the algorithm set back in 1998 when this upper stage was developed," he said.
This problem can be present only during launches of Soyuz launch vehicles equipped with Fregat upper stages from the Vostochny Cosmodrome and can be dealt with through soft-ware methods, Ivanov said.
"This does not apply either to Kourour, Plesetsk or Baikonur because azimuths that could have an angle of 180 degrees do not and cannot exist. This is characteristic of the Fregat upper stage at Vostochny and only during launches to Sun-synchronous orbits. It is a combination of orbit characteristics, launch azimuth, impact areas and weather conditions. This can be "cured" by soft-ware based methods. It has nothing to do with metal, engines or re-soldering. Rather, it is the development of software, fine-tuning and testing by new methods," he said.
Such checks are a time-consuming process, he said, adding that similar emergencies had more than once occurred during launches in different countries earlier.
Roscosmos, for its part, has already formed a special commission that will have to determine the extent of individual senior officials' responsibility for the November 28 accident.
"A commission has been formed to assess the actions of officials and organizations of the rocket and space industry that helped prepare and conduct this launch," Komarov said, adding that he plans to personally take charge of it.
The Soyuz-2.1b LV blasted off from Vostochny on November 28 to put the Meteor-M2-1 remote-sensing satellite and 18 small-sized satellites into low near-Earth orbit. According to sources in the rocket-and-space industry, the Meteor-M satellite was due to separate from the upper stage and start transmitting telemetric data at 9:32 a.m. on November 28, but the telemetry never came because of "a problem in the flight of the Fregat upper stage." As a result, all of the satellites fell into the Atlantic Ocean.
President Vladimir Putin was informed of the failed mission of the Soyuz-2.1b rocket, which had 19 satellites onboard.
Russian Prime Minister Dmitry Medvedev later ordered that Roscosmos' report detailing the reasons for the accident be analyzed and those responsible for it be held to account.