British singer Sarah Brightman has started a gruelling 72-hour survival course in a snowy Russian forest to train for her upcoming role as a space tourist, Russia's cosmonaut training centre said Friday.

The soprano known for her starring roles in West End musicals composed by ex-husband Andrew Lloyd Webber, is due to spend 10 days in space in September after paying $52 million to become the eighth space tourist in a flight arranged by US firm Space Adventures.

This month she began training at the legendary Gagarin cosmonaut training centre in Star City outside Moscow.

In pictures of the survival course released by the training centre, Brightman is shown in a snowy forest of fir trees, lashing tree trunks together to make a shelter while wearing waterproof jacket and trousers and a winter hat.

Temperatures fell to -16 degrees Celsius (3 Fahrenheit) in Moscow this week, followed by heavy snowfall Friday.

Brightman, 54, is in training with cosmonauts and astronauts from NASA, the Russian space agency and the Japanese space agency, as well as with a Japanese businessman who will take over as her replacement on the space flight if she has to drop out.

At a briefing Monday at the cosmonaut training centre, Brightman said: "I would like to say how proud and honoured and excited I am to be part of the Russian space programme and to be a cosmonaut in training."

"I hope.... I can do as good a job as possible and come up to expectations and I will try as hard as I can," she added.

On the survival course Brightman has to spend 72 hours outside and construct a wigwam shelter using branches and a parachute, while knee-deep in snow.

The team members are issued with rations of dried prunes, powdered cottage cheese, biscuits, chocolate, as well as coffee, tea and sugar.

"Cosmonauts and astronauts have to battle freezing temperatures and the harsh conditions of our winter and keep up their morale for many hours," the training centre said.

The aim of the course is to teach survival skills in case the astronauts drift off course when they fall to Earth in their landing capsule and are forced to seek shelter in rough terrain.

The astronauts' Soyuz landing capsule is equipped with medicines and food as well as ultra-warm winter outfits including socks made of animal fur.