Cheltenham Science Festival announces unique hybrid line-up for 2021 With 64 live events and more than 50 free online events, the line-up for the four-day hybrid Cheltenham Science Festival 2021 has been unveiled – with some big stars from the science world, including professor Brian Cox. Professor Brian Cox will be joining a diverse line-up at 2021’s hybrid Cheltenham Science Festival. The UK’s leading scientists, writers and activists are coming together for Cheltenham Science Festival, one of the first post-lockdown festivals of 2021. The hybrid festival will be taking place online and in person from Thursday 10 to Sunday 13 June 2021, with the diverse line-up including Professor Brian Cox, Hannah Fry, Dallas Campbell, Claudia Hammond, Adam Rutherford, Helen Czerski and many more, as well as the next generation of STEM professionals.