That is not one small step for women.

History was supposed to be made Friday when, for the first time ever, two female astronauts were scheduled to do a spacewalk together outside the International Space Station. However, one of the astronauts was switched out this week because of a lack of "spacesuit availability."

Last week, NASA astronaut Anne McClain wore a large-sized spacesuit to conduct her first-ever spacewalk, where she helped swap out aging batteries that store energy collected by the station's solar panels. While she was working, she realized that her suit was too big to maneuver in comfortably. Instead of the large, she would need a medium-sized hard upper torso – what NASA calls "the shirt of the spacesuit."