Tim Peake mission: Growing space-flown rocket seeds

British astronaut Tim Peake has invited thousands of schoolchildren to get involved with his botany experiment, Rocket Science.

The pupils will have the opportunity to grow a packet of rocket seeds that have been on the International Space Station and compare them with identical earthbound seeds.

Dr Alistair Griffiths from the Royal Horticultural Society, which is behind the project, explains why it is hard to cultivate crops in space and why space agencies are keen to do so.