Snapshots from Atlas 5 launch

SpaceX readied a Falcon 9 rocket for takeoff Monday to launch a planet-hunting satellite for NASA that will monitor the light from countless stars to find potentially habitable planets worthy of follow-up studies by more powerful ground- and space-based observatories.

The gates to the Johnson Space Center have been closed to all but essential personnel as heavy rains from Tropical Storm Harvey inundate the Houston area. Flight controllers are on lock down at the Mission Control Center but continue to monitor the health of the International Space Station as usual.

Russian commander Sergey Prokopyev, German flight engineer Alexander Gerst, and NASA astronaut Serena Auñón-Chancellor closed out a nearly 197-day space mission with a landing in Kazakhstan aboard their Soyuz MS-09 crew carry ship at 0502 GMT (12:02 a.m. EST) Thursday. The Soyuz crew undocked from the International Space Station at 0140 GMT (8:40 p.m. EST Wednesday) to begin their return to Earth.