Video: Expedition 50 spacewalk highlights

Two astronauts ventured outside the International Space Station early Thursday and performed what amounted to hand transplant surgery on the lab’s Canadian-built robot arm, removing a crippled grapple fixture on one end of the space crane and replacing it with an on-board spare.

The Russian Soyuz MS-03 spacecraft and booster rocket were rolled out to the launch pad at the Baikonur Cosmodrome on Monday in preparation for liftoff Thursday at 3:20 p.m. EST (2020 GMT) on a two-day trek to the International Space Station.

Outgoing space station commander Shane Kimbrough and two Russian crewmates returned to Earth on Monday, riding a Soyuz capsule in a bubble of hot plasma to a parachute-assisted landing in Kazakhstan. The trio undocked from the space station at 0757 GMT (3:57 a.m. EDT) and landed on the Kazakh steppe at 1120 GMT (7:20 a.m. EDT) Monday.