MIAMI (CBSMiami/AP) – A power system failure at the International Space Station has pushed NASA to move the first all-female spacewalk to this week.

Astronauts Christina Koch (cook) and Jessica Meir (mere) will now venture out Thursday or Friday, instead of next Monday.

A battery power controller failed over the weekend, prompting the change. The women will replace the broken component, rather than install new batteries, which was their original job.

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Last week, astronauts conducted two spacewalks to replace old space station batteries. They have three more spacewalks to go to finish the battery work. A battery-swapping spacewalk scheduled for Wednesday has been called off.

This will be the first spacewalk by only women in more than a half-century of spacewalking.

NASA says the six station astronauts remain safe, despite the failure.

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