The toilet fan on SpaceX's Inspiration4 mission malfunctioned, setting off an alarm, and the all-civilian crew had to be coached on how to fix it

• SpaceX sent four civilians into space earlier in September as part of the Inspiration4 mission.
• The crew had a problem with the toilet after the fan inside it malfunctioned, per a CNN interview.
• SpaceX staff had to instruct them how to fix it, but were interrupted by communications blackouts.

The world's first all-civilian astronaut crew faced an unexpected problem when they flew into orbit earlier this month - they had to fix the toilet fan after it set off an alarm.

The Inspiration4 mission took off on September 16, sending four civilian astronauts into orbit for three days onboard SpaceX's Dragon spacecraft.

SpaceX CEO Elon Musk mentioned in a tweet on September 21 that the Inspiration4 crew had "some challenges" with the toilet, which was located at the nose of the Crew Dragon spacecraft inside a glass dome roof. In an interview with CNN on Thursday, crew member Jared Isaacman explained what had happened.

Toilets in space have fans to generate suction, ensuring any human waste goes in the right direction - but the fan on the spacecraft malfunctioned, triggering an alarm, Isaacman said.

Isaacman told CNN that the SpaceX team had to instruct the Inspiration4 crew on how to fix the fan, but that frequent communications blackouts interrupted the process.

"I would say probably somewhere around 10% of our time on orbit we had no [communication with the ground], and we were a very calm, cool crew during that," Isaacman told CNN.

"We were able to work through it and get [the toilet] going even with what was initially challenging circumstances, so there was nothing ever like, you know, in the cabin or anything like that," Isaacman said.

Isaacman said that the Inspiration4 crew had previously talked to some NASA astronauts about the toilet, and the astronauts told them that "using the bathroom in space is hard, and you've got to be very - what was the word? - very kind to one another."