Space-grown lettuce may sound like something from science-fiction, but astronauts on the International Space Station, or ISS, have been enjoying their leafy greens since mid 2015, thanks to NASA's Veggie plant growth system. Megan McGregor spoke to Gioia Massa, project scientist at Kennedy Space Centre, and Howard Griffiths from the University of Cambridge... Like this podcast? Please help us by supporting the Naked Scientists