MOSCOW, Oct. 29 (Xinhua) -- The cooling system of a Russia-developed nuclear-powered spacecraft has passed ground tests, according to materials published on the government procurement website on Monday.

The tests of the most important element of the megawatt-class have been conducted successfully under conditions as close as possible to outer space, with results meeting the requirements of the technical specifications, the website said.

The project was developed by the Keldysh Research Center at the request of the Russian state space corporation Roscosmos.

Russia has been developing a unique project to create a spacecraft on the basis of megawatt-class nuclear electric propulsion since 2010.