Live coverage: Soyuz crew capsule departs station, lands in Kazakhstan

This video replay shows the Falcon 9 rocket’s flight from liftoff until deployment of the Dragon supply ship, including the dramatic touchdown on a drone ship in the Atlantic Ocean.

Ground crews loaded time-critical experiments, including 20 mice to help scientists study muscle atrophy, into SpaceX’s commercial Dragon cargo capsule Thursday, a day before a launch planned from Cape Canaveral toward the International Space Station.

After four years of brainstorming, custom tool development and training, two astronauts plan to venture outside the International Space Station Friday for the first of four spacewalks to repair a $2 billion cosmic ray detector. The excursions are considered the most challenging since work to service the Hubble Space Telescope.