Ukraine and the United States are preparing the resumption of launches of Antares modernized launch vehicle from Wallops Flight Facility (Virginia, U.S.) that delivers cargos to the International Space Station (ISS) under the NASA order, Head of the State Space Agency of Ukraine (SSAU) Liubomyr Sabadosh has said.

"According to the information from our U.S. partners, the launch of the Cygnus cargo spacecraft using Antares launch vehicle scheduled for July 6, 2016 has been postponed for August due to technical reasons: partners are finishing the tuning of new RD-181 rocket engines successfully tested in June," he said.

He recalled that Ukraine is one of the key participants of the Antares program: Pivdenne Design Bureau designed the first stage of the launch vehicle and Pivdenmash made it (both are based in Dnipro).

Early this year Pivdenmash and U.S. Orbital ATK signed a new contract to produce and supply six first stages of Antares launch vehicle for commercial missions of NASA with the option for six more stages. Pivdenmash said that at least two sections of first stages would be delivered in autumn under the contract. Since 2013, eight first stages have been shipped to the U.S. customer under the project, and three of them have not yet been used.

Ukraine and the United States have been cooperating under the Antares program since 2008. Orbital ATK designed the Antares launch vehicle under a contract with NASA worth $1.9 billion.