British astronaut Tim Peake is on his way home from the International Space Station (ISS).
The journey began with a four minute 37 second rocket motor blast - the "deorbit burn" - that set his spacecraft on track for re-entry into the Earth's atmosphere.
In less than one hour, the tiny Soyuz capsule carrying Peake and his two crew mates - American Nasa astronaut Colonel Tim Kopra and Russian cosmonaut Yuri Malenchenko - will parachute down on to the vast flat scrubland of the Kazakhstan steppe.
But first the three men face a scorching rollercoaster ride through the atmosphere with temperatures on the craft's heat shield reaching 1,600C.
Soon after 3am, UK time, the crew members scrambled from the ISS into the Soyuz TMA-19M space vehicle that took them into orbit on December 15 last year.
Closing the hatch marked the official end of Peake's historic mission, which earned him an honour from the Queen for "extraordinary service beyond our planet".
At exactly 6.52am, UK time, sprung hooks were released to undock and free the Soyuz.
An outside camera showed the toy-like spacecraft backing out from the space station with the Earth turning slowly below.
Then as the Soyuz moved further away, assisted by two rocket engine burns, a trick of perspective made it appear as if the astronauts were heading for the moon.
Before landing and at an altitude of 87 miles, explosive bolts will fire, splitting the Soyuz into three parts.
The descent module containing the crew will turn so that its heat shield is pointing in the direction of re-entry.
The other two sections, the service module containing propellant and control systems, and the spherical orbital module that housed the crew during their launch, are allowed to plunge into the atmosphere and burn up.
The capsule is expected to land in a remote location on flat steppe scrubland more than 200 miles from the major Kazakhstan city of Karaganda.
Fifteen minutes before landing, four parachutes will be deployed in succession. One second before touchdown, retro rockets will fire and the spacecraft will hit the ground at 3mph.
Recovery crews will rapidly arrive at the site to help the space travellers out of their capsule and take them for medical checks.