Two astronauts to start replacing 12 old batteries with six new ones, in five spacewalks

Astronauts kicked off the first of five spacewalks to replace old batteries at the International Space Station on Sunday.Christina Koch and Andrew Morgan had to remove a pair of old batteries and install a new one delivered just a week ago. These new lithium-ion batteries are so powerful that only one is needed for every two old ones, which are original to the orbiting lab.The 180-kilogram batteries half the size of a refrigerator are part of the space station's solar power network.[caption id="attachment_7461511" align="alignnone" width="1280"]

Astronauts Christina Koch and Andrew Morgan will be replacing batteries on the ISS. image credit: ANSA[/caption]Astronauts have been upgrading them since 2017. They're halfway done. The old batteries are 10 years old; the new ones are expected to last until the end of the space station's life.These latest battery swaps are especially difficult given the extreme location on the station's sprawling frame.It's too far for the 17-meter robot arm to reach, forcing astronauts to lug the batteries back and forth themselves.That's why so many spacewalks are needed this time to replace 12 old nickel-hydrogen batteries with six new lithium-ion versions.After removing the first old battery, Koch and Morgan took turns holding it as they made their way, inchworm style, to a storage platform where it needed to be placed.The battery was so bulky that it blocked the spacewalkers' views of one another, prompting constant updates."I am right next to you," Koch said at one point. "I have the battery," Morgan replied.

Then Koch had the battery, and so it went until it was in its final spot.Next came the new battery for installation, with the same methodical handover.Before all the heavy lifting, the astronauts had time to take in the view 400 kilometres below."Oh my goodness," Morgan said as he savoured a South American sunrise as the spacewalk got underway. "Pretty awesome."Half an hour later, as the station soared above the Mediterranean, Koch asked, "What are we flying over? It's beautiful."NASA plans to wrap up the five battery spacewalks this month, followed by a Russian spacewalk.Then five more US-Italian spacewalks will be conducted in November and December to fix a key science instrument.NASA is calling it a "spacewalk bonanza."This unusual crush of spacewalks will feature the first all-female spacewalk by Koch and Jessica Meir later this month.Koch is two-thirds of the way through a more than 300-day mission. It will be the longest single spaceflight by a woman.