MOSCOW, March 17. /TASS/. A Russian cosmonaut may be part of the crew of a new US commercial spacecraft that will fly to the International Space Station (ISS) in late 2017-early 2018, a source in the rocket and space sphere said on Tuesday.

"The US side as part of bilateral agreements has proposed making one Russian cosmonaut part of the CST-100 spacecraft’s crew," the source told TASS.

The candidates are Russian cosmonauts Oleg Kotov, Alexander Kaleri, Fedor Yurchikhin and Oleg Artemyev.

"The Russian side will choose the candidate in November-December this year," the source said.

The Russian space agency, Roscosmos, and the Yuri A. Gagarin State Scientific Research-and-Testing Cosmonaut Training Center (GCTC) have made no official comments to TASS.

The CST-100 (Crew Space Transportation), developed by the US Boeing Company, is a four-seat space capsule. Its flight to the ISS is expected to take place between December 2017 and May 2018. The three other crew members will be US astronauts.