(CNN) NASA astronauts Anne McClain and Christina Koch were set to make history Friday as the first all-female crew to conduct a spacewalk at the International Space Station. But Koch will instead be joined by male colleague Nick Hague due to spacesuit availability.

NASA said Monday it has only one spacesuit size medium available at the station. But the agency clarified Tuesday that it has more than one medium-size spacesuit torso aboard but said to stay on schedule with the space station upgrades, "it's safer and faster to change spacewalker assignments than reconfigure spacesuits."

We've seen your tweets about spacesuit availability for Friday's spacewalk. To clarify, we have more than 1 medium size spacesuit torso aboard, but to stay on schedule with @Space_Station upgrades, it's safer & faster to change spacewalker assignments than reconfigure spacesuits. pic.twitter.com/tPisBHaF2p — NASA (@NASA) March 26, 2019

The astronauts were set for a series of three spacewalks to complete work on the International Space Station. On March 22, Hague and McClain conducted the first in the series. McClain and Koch were set to go out together Friday to continue work on installing powerful lithium-ion batteries for one pair of the station's solar arrays.

𝘈 𝘮𝘪𝘭𝘭𝘪𝘰𝘯 𝘥𝘳𝘦𝘢𝘮𝘴 𝘪𝘴 𝘢𝘭𝘭 𝘪𝘵'𝘴 𝘨𝘰𝘯𝘯𝘢 𝘵𝘢𝘬𝘦... pic.twitter.com/2fDXJX94wa — Anne McClain (@AstroAnnimal) March 25, 2019

"However, after consulting with McClain and Hague following the first spacewalk, mission managers decided to adjust the assignments, due in part to spacesuit availability on the station," a NASA statement said

"McClain learned during her first spacewalk that a medium-size hard upper torso -- essentially the shirt of the spacesuit -- fits her best. Because only one medium-size torso can be made ready by Friday, March 29, Koch will wear it."

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