NASA responded to criticism Tuesday over canceling what would have been its first all-female spacewalk assignment by citing concerns with safety and speed.

"To clarify, we have more than 1 medium size spacesuit torso aboard, but to stay on schedule with @Space_Station upgrades, it’s safer & faster to change spacewalker assignments than reconfigure spacesuits," the agency tweeted.

NASA had suggested in a statement on Monday that only one of the correct-size astronaut suits would have been available for Anne McClain and Christina Koch on March 29.

ADVERTISEMENT

"Mission managers decided to adjust the assignments, due in part to spacesuit availability on the station," the statement read.

"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."

The cancellation of the all-female walk was met with criticism on Monday.

Hillary ClintonHillary Diane Rodham ClintonTrump's economic approval takes hit in battleground states: poll This is how Democrats will ensure Trump's re-election The Hill's Morning Report - Trump takes 2020 roadshow to New Mexico MORE tweeted that NASA should simply “make another suit” instead of canceling the walk.

"Humanity: Able to land a rover on Mars and communicate with it, or have a probe get close to a comet hurtling through space. Also humanity: Hmm, we don't seem to have this in your size, Woman Astronaut," Sirius XM's DC correspondent Olivier Knox joked on Twitter. 

Tech journalist Abby Beall also wrote an op-ed in the Independent claiming that the cancellation reveals flaws in space technology when it comes to women.

"The root of the problem is this: the Nasa spacesuits are old, and were not made with women in mind," she wrote.