2009 #USOpen champion @delpotrojuan is lending his tennis knowledge to @Nasa astronaut @Astro_Feustel, who will take part in the first-ever tennis match in space with his crewmates aboard the @Space_Station on Aug. 21! Watch their call live at 12:35p ET and his match at 8:30pm ET live on our Twitter, Facebook, and Youtube. #TMinusNetGeneration #USOpen #USOpen50 #NetGeneration #NetGenNetSet #NASA #space #astronaut #delpotro