Gas Exchange Experiment

Project Description
One of the the three main biological experiments carried aboard each Viking lander; GEX was developed by Vance Oyama at NASA Ames Research Center and designed to test for life under two different conditions. In the first mode, it was assumed that organisms that had been dormant for a very long time under dry conditions on Mars would be revived and stimulated back into metabolic activity by the addition of moisture alone.

Summary provided by: http://www.daviddarling.info/encyclopedia/V/VikingGEX.html