In May 2014 three men were sent into space for a period of six months: the American astronaut Reid Wiseman, German Alexander Gerst and Russian Maxim Surayev. For Wiseman and Barley, it was their first space trip. They take you on a breathtaking adventure. The film follows them during their last months of training in different locations - the NASA center in Houston, Star City near Moscow and the European Centre in Cologne - and ultimately, the launch from Kazakhstan in May 2014. During their six-month stay, the astronauts also shoot footage, giving the viewer an overall picture of what it means to be an astronaut. Zero Gravity is a unique experience full of inside information, fascinating images of space as well as a beautiful story about friendship and devotion.

European Space Agency astronaut Alexander Gerst and his NASA colleague Reid Wiseman are launched into space from the Baikonur Cosmodrome in Kazakhstan. Gerst and Wiseman spend six months in humanity's outpost in space and film many of their activities.