Earlier this month, the US space agency NASA announced that it had scheduled a spacewalk with two female astronauts. This was historic news because there has never been an all-female spacewalk. In the past, missions have been all-male or male-female.
NASA astronauts Anne McClain and Christina Koch were set to make history in the first-of-its-kind mission. They had been scheduled to install lithium-ion batteries at the International Space Station (ISS) on Friday. Yet just 19 days after the initial announcement, the plans have fallen through.
The issue? Spacesuits. Nasa says there is only one medium-size hard upper torso spacesuit ready, yet both women need to wear a medium size on their mission.
In statement on Monday, the space agency said: 'Koch had been scheduled to conduct this spacewalk with astronaut McClain, in what would have been the first all-female spacewalk.
'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.
'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.'
According to the BBC, there are actually enough medium-sized hard upper torso pieces on the space station, but one of the suits is yet to be properly configured for a spacewalk.
The problem would have taken hours to fix, and wouldn't be sorted in time, so NASA decided it would be easier (and safer) to switch astronauts. This means Koch will now still go ahead with Friday's spacewalk, but with her male colleague Nick Hague instead of McClain.
McClain is 'tentatively scheduled' to perform her next spacewalk on 8 April.
According to Space.com, picking the right spacesuit is not as straight-forward as you might think. The human body grows taller due to microgravity (the same thing that causes astronauts to float around in space), which means space stations conduct multiple spacesuit fit checks before preparing for spacewalks.
McClain tweeted this month that she was 2in taller than when she launched.
Soviet cosmonaut Svetlana Savitskaya was the first woman to walk in space 35 years ago. More than 500 people have been into space, but only 11% have been women, Reuters reported. When McClain took part in a spacewalk last week, she became the 13th woman to do so; Koch will be the 14th.
