UNITED NEWS INTERNATIONAL (UNI) — The U.S. space agency removed one of its astronauts from an upcoming mission.

NASA said Jan. 18 that it pulled astronaut Jeanette Epps from a trip to the International Space Station set for June.  

The space agency didn’t explain why Epps was removed but added that she would be eligible for future missions.

A NASA spokesperson called decisions like this “personnel matters.”

ABC News said NASA sometimes pulls crewmembers over health concerns.

Epps would have been the first African-American astronaut to live on board the ISS, likely for a five- to six-month term.

NASA said Epps will now return from her training in Russia to work at the Johnson Space Center in Texas.

Prior to being chosen for NASA’s 2009 astronaut class, Epps worked as an intelligence officer with the Central Intelligence Agency and completed deployments to Iraq.

Epps will be replaced on the ISS mission by Serena Auñón-Chancellor.