In a plant growth chamber in the KSC Space Life Sciences Lab, plant physiologist Ray Wheeler checks onions being grown using hydroponic techniques. The other plants are Bibb lettuce (left) and radishes (right). Wheeler and other colleagues are researching plant growth under different types of light, different CO2 concentrations and temperatures. The Lab is exploring various aspects of a bioregenerative life support system. Such research and technology development will be crucial to long-term habitation of space by humans.