Much of an astronaut’s leisure time is spent staring back at Earth, they just can’t stop looking back at home. Major Tim Peake journeys into the misunderstood phenomenon of homesickness.

Tim had never experienced it until he found himself looking through the copula window of the space craft, which orbited earth several times before reaching the International Space Station. The British astronaut spent 185 days, 22 hours and 11 minutes in space and during that time, developed a deep longing for home, particularly fresh air, nature and the colour green.

But what is this powerful desire for home? Is homesickness a psychological illness? A cultural phenomenon? Or something else? Psychotherapist Sarah Temple-Smith who works for the Refugee Council believes the condition is widely misunderstood and its impact critically under-appreciated. She believes it’s a deep-rooted condition with existential consequences.

Speaking to those who suffer from it, and those who study it Tim attempts to understand exactly what homesickness is: how it manifests, what it feels like, and the psychological triggers that underpin it.

Produced by Kate Bissell and Gail Tolley Sound Design by Joel Cox Developed by BBC Scotland Productions Photo credited to Tim Peake/ESA