UK astronaut Tim Peake is ready to make his landmark flight to the International Space Station (ISS).
The ex-helicopter pilot – with American Tim Kopra and Russian Yuri Malenchenko – will launch on a Russian Soyuz rocket at Baikonur Cosmodrome, in Kazakhstan.
Mr Peake is the first official UK astronaut. Previous “British” astronauts have either had US citizenship and worked for Nasa or been privately funded.
On the ISS he will conduct experiments.
He will also carry out educational activities designed to get young people interested in science.
Fuelling of the rocket has begun ahead of the launch – set for 11:03 GMT – from Site 1 at Baikonur, the pad where Yuri Gagarin made the first historic human spaceflight in 1961.
The Soyuz space capsule is due to dock with the space station at 17:23 GMT.
Helen Sharman became the first British citizen to travel to space when she visited the space station Mir in 1991. Her mission came about through a co-operative venture between the Soviet government and British business.
Ms Sharman told BBC News: “Launch itself is a day that you want to get on with, because finally, you’re getting to do what you’ve been trained to do for so long. I trained for 18 months, Tim Peake will have trained for six years by the time he flies.
“You’re part of a great big machine… by that stage, the team is so big – the doctors, the trainers – that you’re not going to be able to go wrong.”
The crew are placed in quarantine for two weeks before launch to ensure they do not become ill in space.
They woke up at 02:00 GMT (08:00 local time) for breakfast and after a farewell ceremony, they left the cosmonaut hotel in Baikonur for medical tests.
After a break, they got into their white “Sokol” suits – which are worn during launch and re-entry – before saying final farewells to their families.
Then, at about 08:00 GMT (14:00 local time), the crew boarded a bus to the launch pad, where they rode the lift to the top of the Soyuz rocket.
Mr Peake and his colleagues will then be strapped into their seats so that they can prepare for launch.