‘Stranded’ astronauts finally heading home – but what can being in space for so long do to your health?

Explainer
Explainer
‘Stranded’ NASA astronauts are finally heading home – but what can being in space for so long do to your health?

An eight-day mission has turned into a nine-month space stint for two NASA astronauts who are finally set to come home. But why have they been away for so long – and what are the effects of such a lengthy stay in space?