NASA announced recently that scans of the Martian geology had revealed the presence of large quantities of water on the planet, paving the way for a manned mission to Mars in the future. But how will these Martian pioneers find the water, and equally importantly, oxygen on the red planet ? Scientists Don Sadoway, from MIT in Boston, and Ken Debelak, from Vanderbilt University in Tenessee told a NASA conference this week how to do it. Sadoway has designed an electrochemical cell the size of a fridge, which powered by a small nuclear reactor. Oxide-rich rocks, which make up the surface of Mars are loaded into the cell which passes a 450 amp current through the rocks, melting them, and releasing oxygen by a process known as electrolysis. People need about 3 kilograms of oxygen per day, which the cell should be able to extract from only 8 kilograms of Mars rock. So what about the water ? Debelak, the other scientist, has suggested using the same technique employed home here on earth to make decaffeinated coffee ! By compressing carbon dioxide gas, which makes up most of the atmosphere on Mars, it can be used to dissolve some of the water locked up in minerals and rocks on the planet surface. When the compressed gas has passed over the rock samples it is allowed to expand which releases clean water which can be collected and used.