Scientists are growing plants on a stone wool substrate made from solidified lava and basalt. One cubic metre of basalt produces 50cu m of stone wool.
"This is enough to grow 350,000kg of tomatoes or one million cucumbers," according to substrate specialist Grodan, which is working with the University of Guelph in Ontario, Canada.
"With minimum use of water and nutrients, maximum yield per square metre can be achieved from the lightweight material."
The first manned mission to Mars is due in 2035 and will take 14 months. "Taking food supplies is impossible. It would amount to 1,500kg per person," said a Grodan representative. "The solution lies in growing their food."
When they touch down on the red planet, the astronauts will have to put up greenhouses that have an artificial atmosphere because air pressure is less than one per cent of Earth's.