Video: Expedition 50 spacewalk highlights

Legendary cosmonaut Alexei Leonov, the first human to walk in space — an experience that almost killed him — and later the commander of the Russian Soyuz spacecraft that docked with a NASA Apollo capsule, symbolizing a historic thaw in the Cold War, has died after a long illness, the Russian space agency confirmed Friday. He was 85.

Astronauts Randy Bresnik and Mark Vande Hei headed outside the International Space Station Thursday on a spacewalk to replace one end of the lab’s Canadian-built robotic arm, a changeout that engineers say will restore the device to full capability.

Two astronauts worked outside the International Space Station Wednesday to reposition two spare solar array ammonia coolant pump assemblies, putting a failed unit, dubbed “Leaky,” into long-term storage and attaching another, known as “Frosty,” to an appendage of the lab’s robot arm.