Former NASA Astronaut Dr. Tom Jones shares his experiences in space and offers tips for future explorers 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.