March 26 (UPI) -- NASA canceled what would have been the first all-female spacewalk at the International Space Station on Monday because it did not have the right size spacesuit for both women to complete the mission.
Astronauts Anne McClain and Christina Koch were supposed to make the historic spacewalk on Friday, when they were to install lithium-ion batteries to one pair of the station's solar arrays.
When McClain did a spacewalk with fellow astronaut Nick Hague on March 22, she discovered that the medium-size upper torso portion of the spacesuit fit her best. However, it is the same size Koch needs and there is only one available at the space station, NASA said in a news release.
"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," NASA said in a statement Monday.
"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," the statement continued.
Koch will now do Friday's spacewalk with Hague. McClain will do a spacewalk with Canadian Space Agency astronaut David Saint-Jacques on April 8.
McClain worked with both the medium and small suits during training sessions on Earth and initially believed the larger suit would work well for her. After the March 22 spacewalk, though, she determined that the medium suit was a better fit for her.
"When they launch on board, we know pretty well what suit size they are but, of course, your body changes slightly in space due to fluid shifts or spine elongation," Mary Lawrence, a NASA spacewalk flight director, said last week in a SpaceNews.com article.