who is training at Star City near Moscow, is due to blast off on a Russian Soyuz craft on 1 September.
The 54-year-old will spend 10 days aboard the International Space Station (ISS), 260 miles (420 km) above Earth.
Brightman said singing in space was a "very different" proposition to performing on Earth.
"To sing in microgravity is a very different thing to singing down here," she said. "We use the Earth to ground ourselves when we sing and the air around us."
While in space, Brightman will conduct several experiments, one of which is the effect zero gravity will have on her voice.
Source: BBC News