Roscosmos finds primary cause behind Soyuz booster failure

Moscow  :   The collision of elements during the separation of the Soyuz rocket's first and second stages is the primary cause behind the booster failure that forced the two astronauts on board to abort the launch and make an emergency landing, the media reported.

"There are no final versions but the primary cause is understandable and is related to the collision of a side element making part of the first stage," Sergei Krikalyov Executive Director for Manned Flights at Roscosmos, was quoted as saying by TASS news agency on Friday.

"A collision occurred during the separation of the first and second stages," the Krikalyov added.

The Soyuz MS-10 launched from the Baikonur Cosmodrome in Kazakhstan to the International Space Station (ISS) at 4.40 a.m. on Thursday with Russian Cosmonaut Alexey Ovchinin and US astronaut Nick Hague on board made an emergency landing after their rocket malfunctioned.

According to NASA, there was an "issue with the booster" and the crew returned to Earth in a ballistic descent mode, which is a sharper angle of descent compared to normal.

"A deviation from the standard trajectory occurred and apparently the lower part of the second stage disintegrated. The rocket stopped its normal flight and after that the automatic system did its work," Krikalyov said.

An element of the booster's first stage collided with the second stage.

"This could have been caused by the failure of the system of the normal separation, which should have been activated. We will analyze the causes in detail," the Roscosmos official said.

The results of the government probe into the causes of the Soyuz-FG rocket's failure will be available later this month, the report said.

"The panel of inquiry got down to work yesterday. The results are expected after October 20. The first components found in Kazakhstan's steppe will help find out what happened. The necessary measures will be taken afterwards and flights will be continued," Krikalyov said.

He added that all rockets of this class will be authorised for use again only when the causes of the failure were clear.