Japanese astronaut Onishi Takuya, a former passenger jet pilot, will head to the International Space Station around 2025.
Science and technology minister Moriyama Masahito announced Onishi's long-term mission at a news conference on Tuesday. It will be Onishi's second trip to the space station following his previous stay there in 2016.
The Japan Aerospace Exploration Agency says Onishi will hold a news conference on Wednesday.
Meanwhile, it has been decided that the mission of another Japanese astronaut, Yui Kimiya, initially scheduled around next year, will be delayed by one year to around 2025.
Astronaut Furukawa Satoshi has been conducting scientific experiments at the space station since August, focusing on research for future manned space exploration.