Space food: Pie in the sky or a taste of the future?

In the science fiction movie The Martian, the astronaut stranded on the Red Planet lives for more than 500 days on potatoes he has grown while awaiting rescue.

The scenario in the film may become reality someday, but right now ambitions are pitched a little lower. After all, humans have yet to set foot on Mars and so far, astronauts have only tasted extraterrestrial food in the form of lettuce grown on the International Space Station.

An experiment is now underway to grow rice and thale cress aboard Tiangong II, China's latest space lab, which was launched in September.