Video: Change of command aboard International Space Station

Space station commander Chris Cassidy and Robert Behnken floated back outside Tuesday for their fourth spacewalk in less than a month, completing preparations for future upgrades including the eventual installation of an airlock that will allow commercial experiments to be moved into and out of vacuum as required.

Ready for a resupply run to the International Space Station, a SpaceX Falcon 9 rocket was raised vertical at Cape Canaveral’s Complex 40 launch pad Wednesday ahead of a planned liftoff with more than 5,700 pounds of science experiments and crew supplies.

A Russian Soyuz rocket made a railroad journey Wednesday to its launch pad in Kazakhstan, two days before blastoff with a crew of three spaceflight veterans from the United States, Italy and Russia heading for the International Space Station.