Dr Epps was to have been the main African-American astronaut appointed to the space station group.
She would have flown on board a Russian Soyuz flight in June yet is being supplanted by another space traveler.
Nasa has not given an explanation behind pulling back her but rather says she will be considered for future missions.
Jeanette Epps, conceived in Syracuse, finished a doctorate in advanced plane design in 2000. Subsequent to graduating, she worked in a research facility for a long time before being selected by the Central Intelligence Agency (CIA).
She filled in as a specialized knowledge officer for a long time before being chosen as an individual from Nasa’s 2009 space explorer class. Her opportunity with the CIA included organizations to Iraq.
In a meeting with Elle magazine a year ago, Dr Epps stated: “I get extremely energized when I consider being up in space, incompletely in light of the fact that I contrast it with going into a battle region.
“Both are extremely unsafe in any case, for me, it’s an easy decision: I would preferably confront the threats in space than backpedal to a battle region.”
She included: “When individuals return from space, I perceive the amount they need to go once more.”
Dr Epps was because of dispatch to the circling station from Baikonur, Kazakhstan, alongside the German European Space Agency (Esa) space explorer Alexander Gerst and the flight’s officer, Russian cosmonaut Sergei Prokopev.
Nasa offered no explanation behind the choice to expel her from the Expedition 56/57 mission. In an announcement, they said she would “come back to Nasa’s Johnson Space Center in Houston to expect obligations in the Astronaut Office”.
Her substitution, Serena Auñón-Chancellor, is a restorative specialist from Fort Collins, Colorado. Dr Auñón-Chancellor beforehand spent over nine months in Russia supporting therapeutic operations for space station team individuals.