Video: Soyuz MS-01 leaves the space station for landing

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.

The last of Japan’s current series of HTV cargo freighters arrived at the International Space Station Monday with a fresh set of lithium-ion batteries, ready for installation on the research lab’s solar power truss after the scheduled docking of a two-man crew on a SpaceX Dragon spaceship later this week.

A refurbished SpaceX Crew Dragon spaceship linked up with the International Space Station early Saturday more than 260 miles above Earth, delivering four veteran astronauts to the orbiting research complex and temporarily raising the lab’s crew complement to 11.