Watch: Astronauts enjoy zero-gravity Olympics

Astronauts have been "getting into the Olympic spirit" with a zero-gravity Olympics of their own, according to Nasa.

In a video message released by the US space agency, astronaut Matt Dominick wished athletes well as they prepare to perform in this years' Olympic games.

The footage was recorded on board the International Space Station, which circles the Earth every 90 minutes at an altitude just above 400km (250 miles) above surface level.