Professor Brian Cox and Dara O Briain present live coverage celebrating British astronaut Tim Peake's space mission as he blasts off to become the first Briton to serve on the International Space Station. They are joined at the Science Museum in London by astronauts including Chris Hadfield, the former commander of the ISS, alongside thousands of people who are there to cheer Tim on. Meanwhile, in sub-zero temperatures in Kazakhstan, Dallas Campbell reports live from the Soyuz rocket launch site.