Jeanette Epps: Nasa drops woman who was set to be first black resident crew member on International Space Station

A woman who was set to become the first black astronaut to serve as long-term crew member aboard the International Space Station has been withdrawn from the mission, Nasa said.

The space agency said on Thursday it had pulled Jeanette Epps from a flight scheduled to launch in June, and will send Serena Auñón-Chancellor in her place.

Both women were selected as astronauts in 2009 and Ms Auñón-Chancellor had been her colleague's back-up for this mission, according to reports.

Ms Epps "will return to NASA’s Johnson Space Centre in Houston to assume duties in the astronaut office and be considered for assignment to future missions," Nasa said.

It did not give a reason for the reassignment.

Pressed on the decision by Ars Technica, a Johnson Space Centre spokeswoman said: "A number of factors are considered when making flight assignments. However, these decisions are personnel matters for which Nasa doesn’t provide information."

Ms Epps is a former CIA intelligence officer who holds a PhD in aerospace engineering.

She had wanted to work for Nasa since childhood, she said last year, and had "always had strange dreams of being in nothingness, just floating in complete darkness".

Describing how she was looking forward to the possibility of performing a space walk, she wrote in Elle: "Soon, it will no longer be a dream."