The Russian space agency began its investigation of the Proton launch failure that left the Arabsat 4A satellite in the wrong orbit, International Launch Services (ILS) announced. Preliminary flight information on the Feb. 28 launch indicates that the Breeze M upper stage shut down early during its planned burn sequence.

The state commission formed by Roscosmos is led by Victor Remishevsky, deputy director of Roscosmos and includes members from Proton manufacturer Khrunichev. The commission plans to complete its work by March 30.

ILS is forming a separate failure review board chaired by Eric Laursen, ILS vice president and chief engineer. The oversight board review the methods, conclusions and corrective action recommended by the Russian state commission. ILS is a U.S.-Russian joint venture that markets commercial launches of the Proton rocket. The satellite, manufactured for Arabsat by EADS Astrium, was designed to provide communications services to Arab countries and neighboring regions.

The next Proton launch tentatively is scheduled for May 17. The ILS mission will place the Hot Bird 8 satellite into orbit.