Four Angara carrier rocket will be accepted for service this year but not all of them will blast off by January, Head of Russia’s State Space Corporation Roscosmos Dmitry Rogozin told TASS on the sidelines of the St. Petersburg International Economic Forum on Thursday.

"This year, we will most likely try to commission four rockets: two heavy and two light launch vehicles. However, this does not mean that all of them will lift off this year but two of them will make their spaceflight: one light and one heavy rocket," Rogozin said.

A heavy rocket will be commissioned in June and a light carrier in July. The other launch vehicles are expected to be commissioned by the end of the year, the Roscosmos chief said.

A heavy Angara-A5 rocket is due to test a new booster this year, Rogozin specified.