Renowned oceanographer Dr. David Gallo dives into the unknown world deep under the sea to discuss ocean exploration, unexplored creatures and territory and the technology required to make it happen at the inaugural X-STEM Symposium in Washington, D.C. on April 24, 2014. br The X-STEM Symposium is sponsored by MedImmune and the Northrop Grumman Foundation and is a program of the USA Science & Engineering Festival. br Lockheed Martin is the Founding and Presenting Host of the USA Science & Engineering Festival.