NASA was forced to cancel its historic first all-female spacewalk due to the fact that the astronauts didn't have more than one spacesuit size. 

Anne McClain and Christina Kouch were slated to conduct the second out of three scheduled spacewalks on Friday, March 29. McClain had done the first one was NASA's Nick Hague on March 22. 

NASA said that after consulting with McClain during the first spacewalk, mission managers had to change the following spacewalk assignments because both Koch and McClain required a medium-sized upper torso - essentially the shirt of the spacesuit - and there was only one available for Friday. 

According to a statement posted on NASA's website, Koch will be conducting the second spacewalk while McClain is slated for the third on April 8th. 

The March 29 spacewalk is scheduled to start at 6:20 a.m. ET, while the April 8 spacewalk is set to start at 6:05 a.m. ET.

The second spacewalk will be finishing work done in the first one, which was to install powerful lithium-ion batteries for one pair of the station's solar arrays.