Expedition 60 Flight Engineers Nick Hague and Andrew Morgan of NASA will begin their planned six-and-a-half-hour
spacewalk from inside the Quest airlock about 8:20 a.m.
NASA said McClain realised during her first
spacewalk with fellow astronaut Nick Hague that a medium-sized hard upper torso, which the agency calls "the shirt of the spacesuit," fitted her best.
McClain is scheduled to
spacewalk on April 7 for the second time, having done so already on March 22.
During repressurization of the station's airlock following the
spacewalk, a spacesuit configuration issue put the suit Mastracchio was wearing in question for the next excursion - specifically whether water entered into the suit's sublimator inside the airlock.
We do our best to anticipate the spacesuit sizes that each astronaut will need, based on the spacesuit size they wore in training on the ground, and in some cases astronauts train in multiple sizes," she said in explaining the problem that hampered Friday's planned
spacewalk.However, individuals' sizing needs may change when they are on orbit, in response to the changes living in microgravity can bring about in a body.
Anne McClain and Christina Koch had been due to step into history books in a
spacewalk on Friday, during the final week of Women's History Month.
The next step was for flight controllers to turn on the power inside the fledgling station; electricity had been turned off to the cables before the
spacewalk began, for the astronauts' safety.
The
spacewalk will go ahead on Friday, but Ms Koch will now be accompanied by her male colleague Nick Hague, rather than Ms McClain.