Christina Koch and Anne McClain had planned to step outside the International Space Station in a historic moment, out to a floating lab to install batteries to be charged up from its solar arrays.
However at the last moment, it became clear that both women needed medium-sized space suits, and there was only one readily available.
Koch ended up exiting the ISS with her male colleague, Nick Hague instead, wearing the medium suit.
McClain had trained in both medium and large spacesuits but realised at the time of the spacewalk that the medium fitted her better.
So what was the problem?
The suit’s fit relates to the hard upper torso area. Although Nasa has two medium-sized hard upper torsos, only one of them had been properly configured to be used on a spacewalk.
People had been excited to see a spacewalk conducted only by women – a first. When it never happened, they took to social media to share in their disappointment.
Mainly, people were wondering - how come there weren't enough medium-sized suits, to begin with?
Some people hadn't understood what the issue was - how could there not be enough suits? Also, not all men wear a large...
Others pointed out that it technically wasn't 'cancelled' it had just been shifted
There was also this:
Nasa spokesperson Stephanie Schierholz said:
We have another medium-size spacesuit segment on the station; Anne trained in M and L and thought she could use a large but decided after Friday’s spacewalk a medium fits better.
In this case, it’s easier [and faster!] to change spacewalkers than reconfigure the spacesuit.