Three robots are growing vegetables on the roof of the University of Melbourne's student pavilion. As I watch, a mechanical arm, hovering above the crop like a fairground claw machine, sprays a carefully measured dose of water over the plants. The greens themselves look fairly terrestrial – cos lettuce, basil, coriander and moth-eaten kale – but they are actually prototypes for a groundbreaking research mission to grow fresh food in outer space. The project leader, Prof Sigfredo Fuentes, leans over and picks a tiny caterpillar from a kale leaf. "We had a real plague of cabbage moths last week, but it's OK; the kale's just here to distract them from the other vegetables." Prof Fuentes is part of the wonderfully named Australian Research Council Centre of Excellence in Plants for Space – a seven-year collaboration between five Australian universities – which has partnered with 38 organisations, including Nasa, to crack the code of fresh, nutritious "space food".