NASA astronaut Jeanette Epps, who was slated to become the first Black crew member to live on board the International Space Station, was unexpectedly pulled from her June flight, reports a number of media outlets, including the Washington Post, which is also claiming her brother is claiming her dismissal from the mission may be due to racism. In a news release, NASA announced that Serena Auñón-Chancellor, a fellow member of Epps’s astronaut class who was scheduled to launch later in the year, would be bumped up to take Epps’s place. Epps, who had already started training for her role on Expedition 56-57, will return to Johnson Space Center in Houston, where she will be a candidate for future crews. NASA did not give an explanation for the crew change. But Epps’s brother blamed racism at the space agency. “My sister Dr. Jeannette Epps has been fighting against oppressive racism and misogynism in NASA and now they are holding her back and allowing a caucasian astronaut to take her place!” Henry Epps wrote in a Facebook post Saturday. He linked to a petition asking NASA to reinstate Epps. In an email, Epps said she could not comment on her brother’s post or the reason for the crew change and clarified that neither she nor anyone in her family created the petition. Epps said that she did not have a medical condition or family problem that would have prevented her from participating in the mission and that her overseas training in Russia and Kazakhstan had been successful. NASA likewise declined to comment about Henry Epps’s post but provided a statement saying, “Diversity and inclusion are integral to mission success at NASA and we have a diverse astronaut corps reflective of that approach.” Last-minute crew changes are not unusual at NASA. Apollo 13 pilot Ken Mattingly was pulled from his mission days before launch after being exposed to German measles. It’s also common for NASA to give limited explanations for these changes, which may involve private medical reasons or other sensitive information. Epps, who has a PhD in aerospace engineering, was selected as a NASA astronaut in 2009 after seven years of working for the CIA. During an interview with New York magazine last year after her historic assignment to the ISS crew was announced, Epps said she felt “a huge amount of responsibility.” Fourteen African American astronauts have flown in space, and several have visited the space station. In 2008, astronaut Leland Melvin was part of the space shuttle crew that delivered the Columbus science laboratory to the space station. But Epps would have been the first to serve on the ISS long-term. “As a steward, I want to do well with this honor. I want to make sure that young people know that this didn’t happen overnight. There was a lot of work involved, and a lot of commitment and consistency. It is a daunting task to take on.” Auñón-Chancellor’s selection was also history-making: She will be the first Hispanic woman to live on the space station.