Glenn Freemantle, who won an Oscar for sound editing on the film Gravity, sonically recreates stories from real-life astronauts on the fiftieth anniversary of the first spacewalk.

In late 2010, Gravity director Alfonso Cuarón presented Glenn Freemantle with a challenge - to create authentic sound design in the vacuum of space. In 2014, Glenn won an Academy Award for Best Sound Editing for his work on the film. Now, to commemorate the 50th anniversary of the first-ever spacewalk, Glenn sonically recreates the stories of real-life spacewalkers.

Cosmonaut Alexey Leonov completed a major Space Race hurdle by performing the first-ever spacewalk in March 1965. Alexey ran into serious problems with his suit pressure and was barely able to re-enter the airlock. Since Leonov's tense inaugural moments, there have been 175 successful spacewalks devoted to maintenance of the International Space Station alone.

In this programme, we'll meet some of the spacewalkers and walk through what the experience is like floating in zero gravity above the earth. Canadian astronaut Chris Hadfield describes his awe at flying weightless above the earth. Record-holding astronaut Sunita Williams describes her spacewalking experiences accumulated over more than fifty hours. Steven Smith describes the enormous pressure helping repair the Hubble Space Telescope. And Italian astronaut Luca Parmitano describes his dramatic 2013 spacewalk, when he almost drowned in his helmet.

Along the way, Glenn will use sound to help us feel the vacuum of space, punctuated by breaths, heartbeats, vibration, the radio crackle, the whoosh of the airlock. The thoughts and feelings of the spacewalkers describing the most awe-inspiring visions of their lives is dramatically contrasted with the odd sounds around them.

Produced by Colin McNulty

A Whistledown production for BBC Radio 4.