Refreshing Drinks of Fresh Air

As much as bullets or body armor, rations or radios, an army needs water to survive — especially when it’s fighting in the blistering heat of an Iraqi summer. But hauling a soldier’s daily requirement of three to four gallons of water has become a gargantuan burden to U.S. armed forces. So Darpa, the Pentagon’s mad science division, has come up with a plan for thirsty GIs: Cut the amount of the water they’re carrying in half, and pluck the rest from out of thin air.
Even in the parched Mesopotamian desert, the air holds plenty of water. The trick is getting it out. Machines have been around for years that can cool the air down to the point where water droplets will condense like dew beading on an oak leaf. But they’re energy hogs, using almost 650 watt-hours just to get a single quart of H20. The goal of Darpa’s Water Harvesting program is to extract that water without using up so much power.
Wired News: Refreshing Drinks of Fresh Air