Washington | NASA has ordered a safety review of the two companies it has hired to fly astronauts to the International Space Station, a months-long assessment that would involve hundreds of interviews designed to assess the culture of the workplaces, the agency said.

The review, to begin next year, would look at both Boeing and SpaceX, the companies under contract to fly NASA's astronauts, and examine "everything and anything that could impact safety" as the companies prepare to fly humans for the first time, William Gerstenmaier, NASA's associate administrator for human exploration, said in an interview with The Washington Post.