By Lang Whitaker, NBA.com
ALL BALL NERVE CENTER — Houston, we have a problem.
OK, not really. But that sentence should remind us that besides hosting the Houston Rockets, the city of Houston is the home of the Johnson Space Center, which NASA uses for spaceflight training and mission control. With some time off yesterday, Rockets center Dwight Howard paid a visit to NASA HQ to undergo some astronaut training and meet actual astronauts…