ISS: Astronauts Replace Batteries During Spacewalk

⁣NASA astronauts Chris Cassidy and Robert Behnken continued work on replacing the International Space Station's (ISS) ageing nickel-hydrogen batteries with newer lithium-ion ones on Thursday.



The seven-hour-long operation is the crew's third spacewalk in three weeks by the end of which Cassidy and Behnken were expected to conclude the upgrade.



Chris Cassidy arrived at the ISS in April as part of the Soyuz MS-16 space expedition. He's the current head of ISS Expedition 63.



Behnken recently joined the ISS crew aboard the first space flight launched from US soil since 2011, a joint effort of NASA and SpaceX.