NASA Astronaut Eric Boe Removed From Boeing Starliner Test Flight Due to 'Medical Issue'

NASA astronaut Eric Boe has been removed from the test flight of Boeing's Starliner crew transport spacecraft—which is scheduled for no earlier than August 2019—because of a "medical issue."

Two-time space shuttle pilot Boe was selected to be involved in the test flight last year, however, he will now be unable to fly, according to the space agency. He will be replaced by veteran NASA and ISS astronaut Edward "Mike" Fincke.

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"Eric Boe, originally assigned to the mission in August 2018, is unable to fly due to medical reasons; he will replace Fincke as the assistant to the chief for commercial crew in the astronaut office at NASA's Johnson Space Center," a NASA statement read.

Boe was pilot of the Endeavour space shuttle mission STS-126 which launched in November 2008, as well as Discovery's final mission, STS-133, in February 2011. Meanwhile, Fincke has only taken part in one space shuttle mission as Mission Specialist on Endeavour's final voyage, however, he has spent more than 381 days in space, completing over 48 hours of spacewalks.

Boeing's Starliner is being developed as part of NASA's Commercial Crew Program—an initiative where the space agency is collaborating with the American aerospace industry "to develop and operate a new generation off spacecraft and launch systems capable of carrying crews to low Earth orbit and the International Space Station."

The Starliner will be able to carry seven people—or a mix of crew and cargo—into low Earth orbit and can be reused up to 10 times, with an estimated turnaround time of six months.

Alongside Boeing, NASA is also working with Elon Musk's SpaceX who are developing a similar crew transport spacecraft known as "Dragon." Boe and fellow astronauts Bob Behnken, Doug Hurley and Sunita Williams were selected to work closely with Boeing and SpaceX in the development of the Starliner and Dragon.

It is not common for astronaut crew members to be reassigned due to the high levels of preparation and training required for each flight, however, it does happen in some circumstances. Reasons for being removed from a flight may include health, family or personal issues, according to NASA.

A high-profile case occurred last year when NASA removed astronaut Jeanette Epps from her mission to the International Space Station (ISS.) Epps—who would have become the first African American to be part of a long-term mission on the ISS—has said that she still doesn't understand the reasons for her reassignment.

NASA astronaut Eric Boe is seen during an event were it was announced that he, Boeing astronaut Chris Ferguson, and NASA astronaut Nicole Aunapu Mann are assigned to the Boeing CST-100 Starliner Crew Test Flight to the International Space Station, Friday, August 3, 2018 at the Johnson Space Center in Houston, Texas. Bill Ingalls/NASA via Getty Images