Two astronauts floated outside the International Space Station early Friday for the first of four planned spacewalks to wrap up a complex multi-year job to replace 48 aging batteries in the lab’s solar power system with 24 more powerful lithium-ion units.

SpaceX transferred the first astronaut-ready Crew Dragon spacecraft Friday night from a fueling facility at Cape Canaveral Air Force Station to pad 39A at NASA’s Kennedy Space Center, where teams will join the capsule with its Falcon 9 launcher for liftoff later this month.

A Soyuz spacecraft carrying a three-man crew parachuted to the flat grasslands of Kazakhstan on Saturday, returning home from the International Space Station with cosmonaut Yuri Malenchenko, NASA astronaut Tim Kopra and British flight engineer Tim Peake.