Establishing a human colony on the moon and travelling to Mars has been the stuff of dreams since the dawn of the space age.
They are growing vegetables in soils similar to those found on the moon and Mars, looking for ways to help space pioneers grow their own crops.
The US space agency makes ground similar to that on the moon from sand found in an Arizona desert, while Mars crimson soil is scooped from a volcano in Hawaii, Wamelink says.
If analyses show that the vegetables contain arsenic, mercury or iron, making them unfit for human consumption, the soil can be purified by growing other plant species such as violets, which absorb the poisons.
Extremely cold temperatures – dropping to minus 62 degrees Celsius on Mars – as well as a lack of oxygen, means that lunar or Martian vegetables and fruit could only be grown in a closed and controlled environment.
Technology and the know-how to keep astronauts alive on Mars still has a long way to go says Christophe Lasseur, a European Space Agency life support expert, who deals with metabolic aspects of space travel.