Russia’s state space corporation Roscosmos has announced a tender for developing proposals on testing key elements of a megawatt-class nuclear propulsion system, including aboard the International Space Station (ISS), according to the tender documentation posted on the state procurement website on Thursday.

Specifically, Roscosmos expects to receive "proposals on the rational structure of key elements, systems and items of a perspective nuclear propulsion unit intended for tests in outer space, including with the use of the ISS’ Russian segment.

According to the tender documentation, Roscosmos is ready to allocate more than 264 million rubles (about $4 million) for this work.

The winner of the tender is expected to be announced on October 28.

As of now, only the Keldysh Research Center has submitted its bid for this work.

The works on creating a transport energy module based on a megawatt-class nuclear propulsion unit were approved by the Russian presidential commission for modernization and technological development of the Russian economy in 2009.

By the end of 2018, the energy propulsion unit should be prepared for flight and design tests.

It was reported earlier that 3.8 billion rubles ($60 million) would be allocated from the budget for developing a nuclear propulsion unit in 2016-2018. Roscosmos is the project’s customer and the Keldysh Research Center is its contractor. The contract should be fulfilled by November 2018.