The heads of NASA and Russia's space agency will watch American, Russian, and Japanese astronauts launch to the International Space Station from Florida on Thursday, a routine crew rotation flight coinciding with a rare face-to-face meeting between U.

CAPE CANAVERAL, Fla. -- Thick clouds prompted SpaceX to call off Thursday’s planned launch of four astronauts to the International Space Station for NASA. The countdown was halted at the one-minute, 7-second mark. SpaceX's next launch attempt from Kennedy Space Center is Friday, although the weather forecast is less favorable.