Image credit: Andrey Smirnov/AFP/Getty Images

MOSCOW - Famed soprano Sarah Brightman announced today that she had signed up, and paid up, to become the next space tourist.

The classical crossover star has already passed medical and endurance tests at the cosmonaut training facility outside Moscow and is expected to blast off on a Russian Soyuz rocket sometime in 2015. She's expected to spend about 10 days at the International Space Station.

Neither Brightman, nor the company Space Adventures, which brokered her trip, would confirm how much she'd paid for the adventure, but sources told ABC News the price tag was more than $50 million.

In a interview with ABC News after the announcement, Brightman said going to space was something she had always wanted to do, inspired by the space race she witnessed as a child in the 1960s.

"I've wanted to go to space, really, since I was a little girl," she said.

She recalled drawing strength and inspiration from the pioneers of space travel, and said she still gazed at the stars when she's anxious before a performance.

Brightman is poised to become the eighth space tourist. The first was American Dennis Tito, who paid $20 million for the honor in 2001. The most recent was Cirque de Soleil founder Guy Laliberte, who in 2009 became the first clown in space.

Brightman would be the first singer in space and said she may even stage a performance from the space station.

"We're in the planning for that," she confirmed.

Brightman said her stage experience prepared her for the rigorous training for the mission, including tests that simulate eight times the force of gravity.

"It's like an elephant sitting on your chest," she said, laughing.

Brightman's announcement came, perhaps by design, before the release of a new album and a yearlong global tour. After that she'll head back to Moscow for another six months of cosmonaut training.

She said she didn't know yet what to expect from the experience.

"I don't know, and really, nobody knows unless they've been up there," she said.

"I feel very prepared," she added later. "I feel ready to go."

It may be entirely fitting that Brightman is striving to become a space tourist. Her first big pop hit in 1978 was called "I Lost My Heart to a Starship Trooper."