In a rapid-fire crew rotation, a Russian cosmonaut, a NASA astronaut and an Italian flier plan to close out a 139-day mission aboard the International Space Station with a fiery plunge back to the frigid steppe of Kazakhstan aboard their Soyuz MS-05 spacecraft early Thursday.

SpaceX test-fired a Falcon 9 rocket for the second time Saturday after replacing a valve following an earlier static fire test Wednesday. The move has postponed the Falcon 9 rocket’s launch with the Amos 17 commercial communications satellite to no earlier than Tuesday.

A United Launch Alliance Atlas 5 rocket blasted off at 6:18 a.m. EDT (1018 GMT).to deploy the Navy’s fourth MUOS satellite that will expand coverage to encompass the globe with mobile communications.