Expedition 61 flight engineers Christina Koch and Andrew Morgan of NASA concluded their spacewalk at 2:40 pm EDT (Eastern Daylight Time) on October 6. The two NASA astronauts began the replacement of nickel-hydrogen batteries with newer, more powerful lithium-ion batteries on the far end of the station’s port truss during the seven-hour and one minute spacewalk. They were also reportedly able to accomplish several tasks, including the removal of an additional nickel-hydrogen battery, originally scheduled for the second spacewalk.
The new lithium-ion batteries provide an improved power capacity for operations with a lighter mass and a smaller volume than the nickel-hydrogen batteries. 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 400-pound (180-kilogram) batteries, half the size of a refrigerator are part of the space station's solar power network. 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 58-foot (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.
Morgan and Koch are scheduled to venture outside again for another spacewalk to continue the battery replacements on the first of the two power channels for the station’s far port truss on October 11. The next spacewalks dedicated to the battery upgrades are scheduled on October 16, 21 and 25. After completion of the battery spacewalks, the second half of this sequence of spacewalks will focus on repairs to the space station’s Alpha Magnetic Spectrometer. Dates for those spacewalks still are being discussed, but they are expected to begin in November. NASA is calling it a "spacewalk bonanza." This expedition 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.
(With PTI inputs)