The third burn was due to be 18 minutes long but the engines cut out after 7 seconds, leaving the satellites in unusable orbits.
[2][5][6] This was the second launch failure caused by a Briz-M within twelve months as Ekspress-AM4 was lost in August 2011 due to a computer error.
[6] Other recent launch failures included three GLONASS satellites in 2011 and Mars probe Fobos-Grunt on 8 November 2011.
It was reported in early August by Russian newspaper Kommersant that the failure was caused by a fault in the fuel pipe in the Briz-M.
The Khrunichev Failure Review Oversight Board found that it was caused by a faulty component in the pressurisation system.